classroom unit ventilators

Catalog C: UV-1-231F

AAF-HermanNelson®

Self-contained Classroom Unit VentilatorsModels AZS, AZQ, AZR Air Cooled UnitsModels AED, AEQ Air-To-Air Heat Pump UnitsModels ARQ, ERQ Water Source Heat Pump Units

Catalog UV-1-231F / / (6/99) AAF-HermanNelson®

AAF-HermanNelson®

Self-contained Unit Ventilators

• School Classrooms• Conference Rooms

• Hotel Suites• Recreation Rooms

Comfort Conditioning For:

Catalog UV-1-231F / / (6/99)AAF-HermanNelson®

Quality Construction Features ................................................................. 4-5

Design Features ............................................................................................. 6

Welded Frame ........................................................................................................................... 7

Draw-thru Design ..................................................................................................................... 8

Motor/Bearings Design Features ............................................................................................... 9

Damper Operation .................................................................................................................. 10

Room Air/Outdoor Air Damper ............................................................................................. 11

Temperature Controls (MicroTech DDC) ......................................................................... 12-13

Unit Mounted Control Components ...................................................................................... 14

Louvers/Ventimatic Shutter ..................................................................................................... 15

Cabinets & Filters ................................................................................................................... 16

Heat Pump Operation ............................................................................................................. 17

Details and Dimensions ........................................................................ 18-21

Models AZS, AZQ, AZR, AED, AEQ .................................................................................... 18

Models ARQ, ERQ ............................................................................................................ 19-21

Application Considerations ........................................................................ 22

Water Source Heat Pump Models ........................................................................................... 22

Specifications ......................................................................................... 23-31

Air Cooled Units AZS, AZQ, AZR .................................................................................... 23-25

Air-To-Air Heat Pumps AED, AEQ ................................................................................... 26-28

Water Source Heat Pumps ARQ, ERQ .............................................................................. 29-31

©1999 AAF-HermanNelson® Incorporated

The information in this catalog supersedes andreplaces previous [catalogs][bulletins] with regards toAAF-HermanNelson Incorporated Terminal AirConditioning products. Illustrations cover the generalappearance of AAF-HermanNelson products at the timeof publication. AAF-HermanNelson reserves the rightto make changes in design and construction at any timewithout notice.

Table of Contents


In 1917, AAF-HermanNelson® began makingUnit Ventilators and has been manufacturingthem longer than anyone else in the industry. UnitVentilators have proven to be the most energyefficient systems available for maintaining therequired amount of ventilation and precisetemperature control.

AAF-HermanNelson Unit Ventilator systemshave an economical first cost and an economicallife cycle cost. Sophisticated devices modulateindividual room control to adjust quickly tochanges in activity levels and temperatures.Sudden changes in occupancy are adjusted for inthe same manner to maintain a comfortabletemperature throughout the day.

The Self-contained Classroom Unit Ventilatorswere designed to provide optimal comfortlevels with minimal energy consumption. This ismade possible by State-of-the-Art controls andsuperior outside air capabilities which allow theunit to supply “free cooling” a large percentageof the time.

The term “self-contained” refers to the unitdesign, where the entire cooling function is done

Take a Close Look at the Best Unit VentilatorEver Built . . . For Over 80 Years!

AAF-HermanNelson®

Self-containedUnit Ventilator

because they lack the ability to please everyoneall the time. With the Self-contained Unit Venti-lator each room is independently controlled forcooling and for heating. There is no need for centralcooling or heating systems, making the Self-contained Unit Ventilator less expensive to install.

Self-contained Unit Ventilators are available withfactory furnished, fully automatic modulatingcontrols. These controls adjust quickly tocompensate for changes in activity and occupancyso the proper learning environment can bemaintained.

These units are also designed to provide manyhours of “free cooling” using extensive outsideair capabilities. Even in cold northern climates,cooling can be required year round, often whenthe outdoor temperature is below freezing. TheAAF-HermanNelson Classroom Unit Ventilatorutilizes this “free cooling” to maintain anefficient method of comfort conditioningthroughout the year.

Whatever the application may be, there is anAAF-HermanNelson Unit Ventilator to meetthe need.

within the unit. A refrigeration cycle is employedto remove heat from the occupied space andtransfer it to the outdoors where it can be dissi-pated into the atmosphere. With a self-containedsystem, there is no need for a chiller, chilled waterpiping, a remote condensating unit, etc., tosupply cooling.

The Self-contained Unit Ventilator is ideal forretrofit projects. Many older buildings have veryold, outdated heating systems and most oftenhave no cooling systems.

Additionally, these older buildings employed alarge amount of asbestos insulating materials thatcan be toxic if disturbed. Once this material isdisturbed, it must be removed by qualified abate-ment professionals. The Self-contained UnitVentilator is the perfect solution to this dilemmabecause there is no need to make structural modi-fications in order to add heating or cooling. Theonly wall modification necessary is to cut a hole forthe condensing section and the outside air louver.

The Self-contained Unit Ventilator is a greatchoice for new installations as well. Central coolingor central heating systems are often undesirable


The Quality of the Energy SavingUnit Ventilator System

All AAF-HermanNelson Unit Ventilators un-dergo special preparation to assure long-lastingbeauty, resistance to abuse and corrosion.

You will find AAF-HermanNelson’s finish meetsyour most rigid expectations. Here are some ofthe things we do to make sure it does:

1. High-quality furniture steel is carefully inspectedbefore painting. Scratches and marks thatmight show through the finish are removed.

2. After fabrication, the metal undergoes a 5-stagecleaning and phosphatizing process whichremoves cutting oils and forming compoundsand prepares the surface for painting. Thisassures a good bonding surface and reduces thepossibility of peeling or corrosion.

3. Final steps are the application of speciallyformulated Thermosetting Urethane Powderto the exterior. This film is then oven-cured toassure maximum scuff and mar resistance.

4. Textured Thermosetting Urethane Powder whichis highly resistant to scratches and surfacedamage, is used on the top.

5. Finally, they are painstakingly inspected. Weknow the next inspector is you. We want youto be satisfied.

Classroom Unit VentilatorsQuality built by AAF-HermanNelson®

Certified to ISO 9002 to assure the highest quality product

Theseimportant stepsassure yearsof reliableperformance

Outside. . .special care and qualityfor a long-lasting look ofelegance and beauty.


• Motor location out of airstream (away fromhot coil) extends motor life.

• Large diameter, hollow fan shaft providesquiet, economical performance, directly con-nected motor provides for easier maintenance.

• Multi-tap transformer provides fan motorspeed control through “High-Medium-Low-Off” switch.

• Multiple fans provide precise, smooth, quietperformance.

• Antiblow-thru, room air damper preventsgusts of wind from blowing into room.

• Rigid, double wall, insulated outdoordamper of welded galvanized steel.

• Nylon damper bearings assure quiet, main-tenance-free operation of room air, outdoor air,and face and bypass dampers.

• Steam distributing coils assure more evendistribution of steam and more even dischargeair temperature.

• Vacuum breaker relieves vacuum in steamcoil to allow drainage of condensate from coilwhich eliminates water hammer and greatlyreduces the possibility of coil freeze-up.

• Manual air vent and drain plug isfurnished on all water coils.

• UL/CUL built to insure compliance with safetystandards.

• Access panel interlock safety switchprovided on electric heat units.

• Capillary-type overheat thermostatprovides overheat protection across entireelectric heating coil length.

• DDC Controller provided with stand-aloneor network operation.

• Oilable sleeve bearings standard on fanmotor and fan shaft end bearing for quietnessand long life.

• Institutional quality cabinet has durable,textured, scuff-resistant, Charcoal Bronze, bakedenamel top surface which results in lowreflectivity. Baked alkyd enamel paint finishin choice of standard colors on all otherexterior panels.

• Removable bar discharge grille permitseasy cleaning of fan housings.

• Adjustable leveling legs compensate forfloor irregularities.

• Fiberglass insulated unit back also servesas an outdoor air seal.

• Built-in pipe tunnel for field crossover of hotwater or chilled water piping, electrical orrefrigeration tubing.

• Three individual front access panelsprovided for ease of maintenance and service.

Design Features

AAF-HermanNelson is the classroom leader andhas over eighty years of experience in classroomenvironmental control. Many features arestandard for AZS, AZQ, AZR, AED, AEQ, ARQand ERQ models. These features are as follows:

• Tamper resisting, hex socket head,positive positioning threaded fastenersfurnished on all access panels.

• Welded galvanized steel unitized chas-sis provides rattle-resistant operation.

• Insulated, galvanized steel drain panhas welded corners and mastic coating onexterior.

• Hand of drain pan connection is field-reversible.

• Throwaway filter is included in all units asstandard (electric heat units have permanentfilters).

• Single air filter; indoor and outdoor airutilize a common filter.

• Draw-thru design provides uniformed airdistribution across the coil with an evendischarge air temperature.

• Energy efficient fan motor, permanent splitcapacitor (PSC), plug-in type fits all size units.

• Motor has built-in, automatic reset,thermal overload protection.

AAF-HermanNelson Unit Ventilators are highly engineeredto provide an extensive offering of features.


Unitized Welded Galvanized Steel Frame

The AAF-HermanNelson unitized frame (seeFigure 7-3) resists vibration loosening and thechain reaction of problems this can cause. It willbe as strong and as accurately assembled in 25 yearsas it is the first day of installation. This construc-tion assures correct alignment of fan shaft andbearings, and prevents binding of dampers.The AAF-HermanNelson Unit Ventilator is trulyengineered and manufactured to resist abuse overthe years.

Extra StrengthAssures Long LifeThe unique benefits of the welded frame construc-tion (see Figure 7-1) combined with AAF-HermanNelson’s extra-strength steel bar grilles andheavy-gauge metal cabinet casings, provide fullassurance of trouble-free operation and long life.

Unitized welded galvanized steel frame constructionmakes this the most durable Unit Ventilator you can buy.

Figure 7-2Other, CompetitiveFastener Type Construction

Figure 7-1AAF-HermanNelsonWelded Chassis

CompareExclusive AAF-HermanNelson unitized weldedgalvanized steel chassis construction is far superiorto the typical competitive fastener assembledconstruction. Loosened fasteners usually leadto vibration rattles and sagging panels. (seeFigure 7-2)

Figure 7-3AAF-HermanNelsonWelded Chassis


AAF-HermanNelson® Draw-Thru Design

Figure 8-1The AAF-HermanNelson designheating section is safely locatedbelow foreign object “Dropzone.”

The heating element is located away from thetop of the unit, eliminating damage from pencils,crayons, sharp-pointed objects, paper, chewinggum, etc., which may be dropped through the top.

The AAF-HermanNelson Draw-Thru principle isone of the most significant factors that sets theAAF-HermanNelson apart from most competitivemodels. With this system, fans draw air through theentire heat transfer element (see Figure 8-2), ratherthan blowing it through highly concentrated areasof the element (see Figure 8-3).

There are two reasons why AAF-HermanNelson’sDraw-Thru Design is so effective:

(1) Draw-thru design provides uniform dischargeair temperatures.

(2) Draw-Thru fans assure complete, even, heattransfer over the entire length of the heat exchangerfor more efficient Unit Ventilator operation.

Draw-Thru Design Results In Uniform Coil FaceVelocity And Even Discharge Air Temperatures

Draw-Thru Design Permits SaferLocation Of Heating Element

Coil

Coil

Air Flow Shaded

OutdoorAir

Room Air

FilterCoil

Supply Air

• Uneven heat transfer• Uneven discharge air temperature• Uneven air flow• Premature element failure due to hot spots

In the typical blow-thru design (see Figure 8-3),air is forced through limited areas of the heattransfer element. As a result, uneven heat transfertakes place, which translates to uneven dischargetemperatures.

On electric heat units, there is a constant heat inputalong the total coil length in the form of electricenergy, when the coil is energized. Electric heating

Figure 8-3Uneven Air Distribution withTypical Blow-Thru Designs

Disadvantages of some Competitive Blow-Thru Designs

elements must have uniform air distribution acrossthem for optimum element life. Coil hot spotsresult in any area that has a lesser amount of airpassing over it. These hot spots reduce elementlife and are the single greatest cause of prematureelectric heating element failure . . . an unnecessaryand costly maintenance problem.

The use of the AAF-HermanNelson draw-thrudesign with even air distribution over the entirecoil length will greatly reduce the number ofelectric heating element failures, and will extendthe life of the heating elements.

Figure 8-2AAF-HermanNelson Draw-Thru Design With Even Air Distribution

Coil

Air Flow Shaded


Motor Design Features/Quiet Operation

AAF-HermanNelson Unit Ventilator motors offerlow operating current and wattage. See Figure9-1. This can result in savings up to hundredsof dollars per year.

This permanent, split capacitor motor featuresautomatic reset thermal-overload protection, andhas no brushes, contacts or centrifugal startingswitches—the most common cause of motor failure.It is safely located out of the air stream and awayfrom the overheating effect of the heating coil.

Another common cause of motor failure is a lackof lubrication. Even “permanently” lubricatedmotors are supplied with recommended lubrica-tion charts calling for lubrication every five or tenyears. For this reason we recommend thatmaintenance instructions of the motor manufac-turer be clearly followed.

Designed To AssureQuiet OperationThe AAF-HermanNelson Unit Ventilatoris engineered, and manufactured for quietoperation. Airflow patterns, dampers, fans,housings, shafts, motors, insulation, and allother components are thoroughly evaluatedand tested to assure quiet operation.

AAF-HermanNelsonHigh Tech Fan DesignAssures Quiet Operation

Advantages ofAAF-HermanNelson®

Motors and Bearings

Easy Motor RemovalShould it ever be required, motor removal is fastand easy. Location of the AAF-HermanNelsonmotor (see Figure 9-3) is separate from thecomplete fan assembly (which on many unitventilators must be removed with the motor. SeeFigure 9-2). A 1⁄4 horsepower motor is used forall applications.

Motor Located Out of Air StreamAAF-HermanNelson direct-connection driveplaces the motor away from the hot coil, out ofthe air stream. See Figure 9-3. This alsoprevents motor strain often caused by “Whipping”action of unsupported fans on double extendedshafts, which can lead to early motor failure.See Figure 9-2.

Long-Life BearingsThe rotating element has only one large, sleeve-type end bearing and two motor bearings forsmoother operation. See Figure 9-4 and 9-3.Should end bearing replacement ever be required,location of the bearing at the end of the shaft (notin-board like some units - see Figure 9-2) makesfor easy access and fast replacement.

Figure 9-1BrushlessMotor

Fan WheelThe AAF-HermanNelson fan wheels withoffset blades, balanced and precise dimensionsensure smooth, quiet, consistent performance.See Figure 9-5.

Low Sound LevelAAF-HermanNelson fan housings are heavy-gauge steel, and designed to permit air toexpand after it leaves the fan for the smoothest,quietest air flow. Fans are slow-speed design,balanced statically and dynamically for quietoperation. Large fan shafts of ground andpolished steel operate safely, well belowcritical speed. Modular fan construction alsocontributes to equal outlet velocities for quietoperation. These performance-engineeredfeatures result in a quiet Unit Ventilator.

Figure 9-5Fan Wheel

FansCoupling In-Board

BearingFans Motors

Double-extended shaft units with motorlocated in the air stream

In-board bearing, with motor located in theair stream

Figure 9-2. Competitive Designs

Figure 9-3. AAF-HermanNelson Design

Drive shaft solidly anchored and supported onboth ends with motor located out of the air stream

Coupling

Partition

EndBearing

FansMotor

Figure 9-4. Long-Life Bearings


Smooth Air Flow Eliminates Turbulence And Resulting NoiseRegardless of damper positions, AAF-HermanNelson Unit Ventilators permit an even air flow through the unit . . . with no obstructions or restrictedair passages to cause turbulance, vibration and noise.

The Unit Ventilator will besending heated room air intoyour classroom. Usually thisoccurs before occupancy.

Fast morning warm-upusing 100% recirculatedroom air.

Damper Operation

Figure 10-1Return Air Mode

Figure 10-2Mixed AirMode

The Unit Ventilator will besending a mixture of room airand fresh outdoor air into yourclassroom. This usually occursintermittently all day long.

Unit maintaining desiredroom temperature.

The Unit Ventilator will besending only fresh, outdoor airinto your classroom to cool theroom, counteracting the heatgenerated by the pupils, lightsand sun. This also may occurintermittently all day long.

Figure 10-3Outdoor AirVentilationMode

Natural cooling usingmaximum outdoor air.


The typical classroom is cooled by outdoor airover half the time, even in cold climates. It iswell recognized that cooling, not heating, is themain thermal problem in school classrooms.

It is therefore essential that unit ventilatorsefficiently deliver outdoor air when classroomconditions call for “natural” cooling. You buy theunit for its natural cooling ability. With AAF-HermanNelson Unit Ventilators, you are assuredof having outdoor air whenever it is needed.

AAF-HermanNelson Unit Ventilators use all thefilter area at all times for both outdoor air andreturn air, providing relatively constant room airflow at all damper positions. (See Figure 11-1).

AAF-HermanNelson®

Room Air/Outdoor Air Dampers

AAF-HermanNelsonClassroom Damper FeaturesThe standard AAF-HermanNelson outdoor airdamper is made of galvanized steel to inhibitcorrosion, double wall welded construction forrigidity and fiberglass insulation sandwichedbetween the double wall. (See Figure 11-4)Our outdoor damper has additional insulationon the exterior of the outside air damper bladeand on the outdoor air entry portion of the unit.

Both the room air and outdoor air dampers havenylon damper bearings to assure quiet, mainte-nance free operation.

Positive Sealing DamperDampers on AAF-HermanNelson Unit Ventilatorshave turned metal on the long closing edges whichprovide positive sealing by imbedding intovirgin wool mohair. Dampers have wool mohairend seals thus preventing outdoor air fromentering. (See figure 11-4)

Balanced Damper DesignThe AAF-HermanNelson room air damperdesign is free floating and prevents intermittentgusts of cold air from blowing directly into theclassroom on windy days (See figure 11-5).

Some competitors units, which utilize a singlerolldamper, and multiple filters, fail to deliver “rated”air in the outdoor air position because of vari-able resistance to air flow within the unit (seeFigure 11-2).

With the roll damper type unit, when both out-door and room air are admitted to the unit, bothfilters are used. When outdoor air is admittedfor natural cooling, it must now all pass throughonly one filter. This increases the resistance to airflow considerably and reduces the total cfm de-livered to the classroom.

Typical roll damper units are fitted with filterswhich become contaminated at different rates,which prevents delivery of rated air. In addition,at filter changing time, only half-used filters areoften replaced – an additional cost.

Even single filter units, whose design limits theoutdoor air to one half of the filter area and theroom air to the other half, have an air deliveryprofile similar to that shown for the roll damperunit. (See Figure 11-3).

Figure 11-4AAF-HermanNelsonOutdoor Air Damper

Turned Metal

Insulated DoubleWalled Construction

Wool MohairSeal

Wool MohairEnd Seal

TurnedMetal

Figure 11-5AAF-HermanNelson

Indoor Air Damper Design

OutdoorAir

Figure 11-1AAF-HermanNelson Design

Filter (1)

RoomAir

RoomAir

Filter (1)

RollDamper Outdoor

Air

Filter (2)

Figure 11-2Competitive Roll Damper Design

WoolMohair

Seal

Figure 11-3Competitive Design

RoomAir

Filter

R.A./O.A.Divider

OutdoorAir

Gustof

Wind


On stand-alone units the heating setpoint isdetermined by the room temperature adjustmentpotentiometer setting. On network units this “pot”is inoperative and adjustment is done at the frontend computer. The cooling setpoint is determinedby adding the dead band to the heating setpoint.

Typical setpoint values for a heating/cooling unitwould be 76°F cooling and 70°F heating. A roomtemperature above 78°F will cause mechanicalcooling to be initiated. A room temperature below70°F will cause heating to be initiated. When theroom temperature is between 70°F and 76°F, noheating or mechanical cooling is permitted and thisis the “dead band.”

No energy other than fan energy is expended duringthis mode. The room temperature can be heldbetween 70°F and 76°F during a substantialportion of the school year simply by admitting moreor less outdoor air to offset the high internal heatgains associated with school classrooms.

Minimum OutdoorAir PotentiometerThe minimum outdoor air pot located on the UVCallows user adjustment from 0% to 100% on stand-alone units. On network units the factory setting is20% and any adjustment is done by the front endcomputer with the pot on the UVC being inoperative.

GeneralMcQuay International has developed a Direct DigitalControl (DDC) package known as MicroTech,designed specifically to provide sophisticatedtemperature control of AAF-HermanNelsonClassroom Unit Ventilators. The MicroTech DDCpackage can function either as a stand-alonecontroller or as part of a network control from afront end computer.

The use of this AAF-HermanNelson MicroTechDDC package assures a correct sequence of operation,as well as the elimination of any problems whichmay be associated with divided responsibilitybetween the unit manufacturer and the automatictemperature control contractor.

Any stand-alone AAF-HermanNelson Unit Venti-lator can be easily converted later to a networkedunit by the addition of a front end computer,network components, communication wiring andthe simultaneous, one-time, global downloading ofa new software program into all microprocessors inthe unit ventilator network.

AvailabilityMicroTech DDC packages are available for thefollowing AAF-HermanNelson Self-contained UnitVentilators:

1. Air source heat pump with electric heat2. Water source heat pump3. Water source heat pump with electric heat4. DX cooling only5. DX cooling with electric heat6. DX cooling with steam heat7. DX cooling with hot water heat

MicroTech Unit VentilatorController (UVC)The “brain” of the HermanNelson Classroom UnitVentilators MicroTech DDC system is a micropro-cessor-based board (UVC) located in the left endcompartment of the Unit Ventilator. The MicroTechUVC utilizes digital control strategies to maintainprogrammed heating, cooling and ventilationsetpoints. See Figure 12-1.

Dead BandThe AAF-HermanNelson MicroTech DDC systemutilizes separate heating and cooling setpoints. Thisenergy saving feature permits “one-time” setting ofthe desired heating and cooling temperatures. Thiseliminates the need to make seasonal thermostatadjustments. The “dead band” is factory set at 6°F.

Room Air Temperature Sensorsand Tenant OverrideRoom air temperature sensors are available for unitmounting or wall mounting. Unit mounted roomair temperature sensors are located in a samplingchamber located behind a grille in the front panel.A representative sample of room air is continuouslydrawn across the sensor in the sampling chamberby the unit fans during the occupied cycle, thusproviding excellent room air temperature sensing.No separate night setback thermostat is required forthe MicroTech DDC system. The same room airtemperature sensor is used for both the occupiedmode and the unoccupied mode. The unit mountedconfiguration eliminates the problem of selectingthe optimum location for a wall mounted roomair sensor.

The following are the choices of room air tempera-tures sensors available:

1. Unit Sensor with Tenant OverrideThis provides thermistor type temperaturesensing and a unit mounted tenant overrideswitch to allow timed override from unoccupiedto occupied mode.

2. Wall Sensor with Tenant Override, SetpointAdjustment, and CommunicationsThis provides thermistor type temperature sensing,

Figure 12-1. MicroTech Unit Ventilator Controller (UVC)

AAF-HermanNelson® Temperature ControlsMicroTech Direct Digital Control (DDC)


AAF-HermanNelson Temperature Controls MicroTech DDC . . . (Continued)

an LED unit mode indicator, a tenant overrideswitch to allow timed override from unoccupiedto occupied mode, and a setpoint offset adjust-ment potentiometer which allows the user toincrease or decrease the current control setpointby 3°F. A thermometer is provided along with acommunications port.

LED Mode and Fault IndicatorA yellow LED is on the UVC board and a greenLED on the wall mounted room air temperaturesensors. Both LEDs emulate the UVC status byflashing at predetermined intervals to indicate:Occupied Mode, Unoccupied Mode, Tenant Over-ride Mode and Fault Conditions.

Damper ActuatorsThe damper actuators are compact electric/ hydraulictype, factory-mounted, wired and adjusted. Onshutdown, the outdoor air damper will be closedand the face and bypass damper (when used) will bereturned to the full face position allowing air thruthe coil. See Figure 13-1.

Modulating Control ValvesSteam valves are 2-way, normally open, anglepattern. Hot water and chilled/hot water (2-pipe)valves can be either 2-way or 3-way and are normallyopen to the coil. Chilled water valves can be either2-way or 3-way and are normally closed to the coil.See Figure 13-2.

End-of-Cycle ValvesAny unit with a steam coil that is Face & BypassDamper controlled also has a 2-position, 2-way,End-of-Cycle valve to shut off steam flow at the endof the heating cycle.

Any unit with a hot water coil that is Face & BypassDamper controlled that also has a separate coolingcoil has a 2-position, 3-way, End-of-Cycle Valve to shutoff the hot water flow at the end of the heating cycle.

Any two coil unit with a chilled water coil that is Face& Bypass Damper Controlled has a 2-position, 3-way, End-of-Cycle Valve to shut off the chilledwater flow at the end of the cooling cycle.

Master/Slave ControlThe MicroTech DDC system has the capability ofproviding Master/Slave Control for up to a total of6 Stand Alone Units. Master/Slave control fornetwork units is not required since the networkinherently allows all units in a given space to have thesame programmed setpoints if desired.

The master unit provides the control input to theslaves that designates room heating and coolingsetpoints (occupied and unoccupied), minimumoutdoor air damper position setpoint, and theoperating mode (occupied, unoccupied, or tenantoverride).

The object of Master/Slave control is to maintain auniform temperature throughout the space. Thisrequires that each unit in the Master/Slave configu-ration has its own room air temperature sensor toenable it to maintain the room heating or coolingsetpoints dictated to it by the master unit. Commu-nications for the Master/Slave configuration are byparallel wiring between the master and each slave unit.

The Master/Slave configuration requires only oneday/night (occupied/unoccupied) changeoverdevice and it is for the master unit only.

Night Setback Control GeneralAAF-HermanNelson offers various night controloptions to enhance the basic Unit Ventilator control

system. The MicroTech DDC system uses the sameroom air sensor for both occupied (day) and unoc-cupied (night) control which eliminates the usage ofa separate night setback thermostat.

Steam and hot water units provide convective heatduring the unoccupied cycle but remain under thecontrol of the room air sensor to prevent “convectiveoverheating” during the unoccupied cycle. Whenconvective heat is insufficient to maintain theunoccupied heating setpoint, the unit fan motor isenergized until the room air temperature exceeds theunoccupied heating setpoint.

With the MicroTech DDC system, the outdoor airdamper remains closed during the unoccupied cycle.

Network UnitNo additional control wiring is required onMicroTech Network units since the occupied/unoccupied changeover is accomplished via thenetwork communication wiring. MicroTech offersa choice of 26 unique time schedules. Each UnitVentilator controller in the network can be assignedits own time schedule or any number of unit venti-lators can be assigned to the same time schedule.

Stand Alone UnitsOccupied/unoccupied changeover on Stand Aloneunits can be accomplished: manually by a unitmounted day-night switch in each unit, automati-cally by a unit mounted time clock in each unit, orautomatically by a remote mounted time clockwhich operates a unit mounted day-night relay ineach unit.

The unit mounted time clock has a 24-hour dialwith skip-a-day feature and battery back-up. Thetime clock utilizes the unit line voltage power supply.

The remote mounted time clock can be furnished byothers or by AAF-HermanNelson. The AAF-HermanNelson time clocks are 120 volt, 24 hourwith skip-a-day or 7 day and with or without reservepower. It is common practice to have more than onezone which requires a separate remote time clockfor each zone. The remote mounted time clock’sfunction is to energize or de-energize an external(24 volt or 120 volt) control circuit which operatesthe unit mounted day-night relay in each unit in thezone. The control circuit must be deenergized by theremote time clock during occupied cyle andenergized during unoccupied cycle.

Figure 13-1. Damper Actuator

Figure 13-2. Modulating Control Valve


Figure 14-1 shows the location of the standard andoptional AAF-HermanNelson control items. Thefollowing is a general description of these components.

1. MicroTech Unit Ventilator ControllerThis is a factory mounted microprocessor-basedDirect Digital Control (DDC) device which iscapable of stand-alone control or network controlfrom a front end computer. The controller cansupport sixteen (16) inputs and sixteen (16)outputs. Each input supports either analog sensingand/or binary contact closure. Each outputconsists of a binary contact closure to operatecontrolled devices. The controller will providestatus of either the outputs or the inputs uponrequest from a personal computer connectedeither to a network or an individual controller.The controller contains self-diagnostic capabilityto maintain constant reliability. The controllerprovides heating and cooling control in responseto various inputs as well as the room sensor whichmay be either unit mounted or wall mounted.Damper actuators are precisely positioned bymeans of step-and-wait parameters built intocontrol software. Two-position functions such asDX cooling and electric heating are also initiatedby the controller. Room temperature adjustment,unoccupied temperature offset and outdoor airdamper minimum position are all adjustable at thecontroller. In a network system, these three adjust-ments are not operative and are done as part of thenetwork control plan.

The controller provides a visual means of faultdetection with the use of status LED on board.

2. Room Temperature AdjustmentsThis item controls the room temperature setpoint.

3. Damper Actuator(s)These devices position the outdoor and room air

AAF-HermanNelson®

Unit Mounted Control Components

dampers in response to the Unit Ventilator Controller(UVC). Factory mounted, wired and adjusted.

4. Sampling chamberThis enclosure houses the room air sensor when-ever a unit mounted sensor is specified. Room airis continuously drawn through the samplingchamber to ensure fast, accurate response totemperature changes within the room.

5. Defrost timerWhen the unit is in the heating mode, the out-door coil may operate at temperatures low enoughto cause frost to form on the outdoor coil. Theunit has an automatic defrost cycle which operatesat a factory set interval of 90 minutes, but only ifthe outdoor coil surface termperature is below28˚F (-2˚C). The timer is field adjustable for a 30or 45 minute interval.

6. “High-Medium-Low-Off”Motor Speed SwitchAllows user to select the fan speed desired.The “Off ” position shuts unit down completely.

7. Tenant Override SwitchAllows the user to manually override the unit’soccupied mode for up to a preprogrammed twohours.The tenant override value is resettable froma personal computer connected either to a networkor an individual controller. The tenant overrideswitch can also be part of the wall room sensor.

†8. Time Clock (Accessory)This device automatically cycles unit throughoccupied and unoccupied modes in accordancewith a user programmed time schedule. Program-ming instructions are included. Time clocks havebattery backup so they will not require resetting ifelectric power is interrupted. Located in front ofthe room air fan motor.

†9. Holiday Switch (Accessory)This device is furnished with the time clock, avail-able as an accessory. It permits manual changeoverto unoccupied (night) control for extended or oth-erwise unscheduled periods. The switch must bemanually returned to the normal (automatic con-trol) position at the end of the “holiday”period for the unit to operate on the automatictemperature control sequence.

†9. Day/Night SwitchThis manual switch may be used in lieu of auto-matic unoccupied (night) control or remoteunoccupied control. It permits manual changeoverto unoccupied control, but must be manuallyreturned to the “Day” position for unit to operateon the automatic control sequence.

10. Unit Main Power “On-Off” SwitchDisconnects main power to unit for servicing theunit or when unit is to be shut down for anextended period.

11. Emergency Electric Heat SwitchShould the reverse cycle heating system becomeinoperative, this device allows the unit to be manu-ally switched to emergency electric heat. This willpermit the electric resistance heaters to operate asneeded regardless of outdoor temperature.

12. Right End CompartmentClass 1 wiring required.

13. Left End CompartmentClass 2 wiring required.

† Not furnished with network units since thefunction is handled through the communicationnetwork.

Motor 84

10*

12

11*

13

6*

9*

2

1

3

5AccessDoor 7*

CompressorCompartment

*Accessible Thru Access Door

Figure 14-1. Front View With Access Panels Removed


Horizontal and Vertical Blade Louvers

The Ventimatic shutter is a continuously variable,gravity actuated, room exhaust vent which operatesin direct response to positive static air pressure.(See Figure 15-5) Outdoor air which is introducedby the unit ventilator must leave the room in someway. In some states, exhaust vents are required bylaw or code to accomplish this. The VentimaticShutter solves the problem. (See Figure 15-4)

The operation of the Ventimatic shutter isinherently silent. The shutter flaps are made oftemperature resistant, glass fabric that is impreg-nated with silicone rubber for flexibility and longlife. This fabric retains its original properties downto - 50°F. The Ventimatic shutter’s ability toexhaust only the amount of air required results in

Ventimatic Shutter

considerable energy savings. In the heating mode,the unit ventilator brings in only the minimumrequired percent of outside air. The Ventimaticshutter, in turn, exhausts a minimum amount. Inthe cooling mode, when conditions allow, the unitventilator brings in outdoor air for full naturalcooling: The Ventimatic shutter responds byexhausting an equal amount. (See Figure 15-5)

Figure 15-1Water SourceHeat PumpHorizontalBlade Louver

Figure 15-2Water SourceHeat PumpVertical BladeLouver

Two styles of louvers are available for AAF-HermanNelson Self-contained Unit Ventilators.The first style is an architectural design withmultiple break type horizontal blades (WSHPonly, see Figure 15-1). The second style is avertical design with double break type aluminumblades which are split horizontally (WSHP only,

see Figure 15-2). The double break design providespositive water impingement and entrapment butis slightly more restrictive than the horizontaldesign louver.

The Air Cooled Unit and Air-to-Air Heat Pumpuses a vertical blade louver which is split horizontallyto separate outside air intake to exhaust air from theoutdoor coil (see Figure 15-3). All louvers can befurnished unpainted, clear anodized aluminum, orpainted with a color selected by the architect. They arealloy AQ 5005, suitable for color anodizing by others.

AAF-HermanNelson Unit Ventilator louvers canbe used with panel wall, stud wall or masonry wallconstruction. All louvers contain weep holeslocated in the exterior side of the weathertightframe to allow for removal of moisture such asrainwater or condensate overflow.

A wire mesh bird screen is factory installed on theroomside of the louver and both horizontal andvertical blade louvers have a demountable featureto allow access to the unit from outside the building.

Figure 15-3Air Cooledand Air-to-AirHeat PumpVertical BladeLouver

The core of the louver can be removed withoutdisturbing the frame’s weathertight seal that wasmade during installation.

Heavy-duty lattice grilles are also available foreither vertical or horizontal blade louvers. Grillescan be furnished in unpainted, clear anodized orpainted heavy-gauge aluminum. The horizontaland vertical lines of the grilles are designed to “lineup” with the louver blades to present an aestheticappearance.

It is strongly recommended that an AAF-HermanNelson louver be utilized because it is integralto the unit performance. Louvers made by othermanufacturers may be too restrictive or cause excessiverecirculation of condenser air. Either of these con-ditions could have a serious negative effect on unitperformance and possibly cause unit malfunction.Louvers by other manufacturers must always bytested and approved by AAF-HermanNelson priorto their application with AAF-HermanNelsonSelf-contained Unit Ventilator products to ensuresatisfactory unit performance.

louvers on the same wall, equal pressure will keepexcess air from entering through the unit ventila-tor. “Same wall” location also minimizes short cir-cuiting of airflow that can occur with opposite walllocations. (See Figure 15-6)

OutdoorLouver

Figure 15-4. Ventimatic Shutter Assembly

BirdScreen

VentimaticShutter

Figure 15-5Installationof VentimaticShutter toHorizontalBlade WallExhaustLouverNote: All dimensions approximated.

As Directedby Architect

BirdScreen

DrainHoles

CementMortar

Not lessthan 9"

CementMortar

3⁄4" Approx.

Steel ShutterMounting Plate

Steel BaffleLeaf Support(2 Req'd)

Flexible Glass FabricSilicone ImpregnatedShutter Leaf (2 Req'd)

7"

3⁄4" Approx.

Steel InteriorWall Grille(Optional)

Figure 15-6Installation ofInterior Wall Grille

When using the Ventimatic shutter exhaustsystem it is important that the Ventimatic shutterand the unit ventilator wall louvers be mountedon the same wall. This will neutralize the effect ofwind pressure that could force excess air into theunit ventilator’s wall intake louver. By locating the

The Ventimatic shutter is normally mounted onan exterior louver. Large units generally employtwo Ventimatic shutters to insure adequate exhaustair capacity. The two shutters are mounted side-by-side on the same outdoor louver. The size andappearance of the louver used for the unitventilator and for the Ventimatic shutter shouldbe identical. Applying the Ventimatic shutter inthis manner presents an architecturally coordi-nated installation.


Cabinets & Filters

Tamper Resistant AccessHex head (Allen wrench) front panel fastenersdeter unauthorized access to interior of unit. (SeeFigure 16-1)

Removable Discharge GrilleFacilitates cleaning of fans and fan housings.(See Figure 16-1)

Sectionalized Access PanelsAll Self-contained Units are furnished with threeindividual front panels. This feature permitsopening of only the required panel. No cumber-some full length panels to contend with.(See Figure 16-1)

The convenient 12" wide front panels at eachend provide access to piping compartments,temperature control components and High-Me-dium-Low-Off switch. Unlike units that have fulllength front panels, the 12" wide front panelscan be removed without disturbing the normaloperating mode of the unit. The centerfront panel is normally only removed for filtermaintenance and discharge grille removal.(See Figures 16-1 and 16-3)

FiltersAll units are furnished with AAF throw-awayfilters. Additional, permanent wire mesh andrenewable media filters are available. The one-piece filter design makes filter changeout quickand easy. (See Figure 16-3)

Throwaway Filters feature Amerglas media.They are designed to be used once, then discarded.

Permanent filters are metal filters that may beremoved, cleaned and re-used innumberabletimes. (See Figure 16-3)

Renewable Filters consist of frame and renew-able Amerglas media. (See Figure 16-4)

With AAF-HermanNelson’s single filter design,filter changeout takes only seconds. Change only onefilter instead of multiple filters—no hidden filters.

With one-piece filter design, the mixture ofoutdoor air and room air passes through thesingle unit filter. With all air being handledby one filter there is no possibility of unevendust loading which is an inherent danger ofunits with separate filters for room air andoutdoor air.

12" Left FrontAccess Panel

Fan ShaftBearing

12" Left FrontAccess Panel

Filter

Motor

Renewable MediaFilter

Figure 16-1

Figure 16-2

Figure 16-4

DischargeGrille

Front Access Panel

Screen

Discharge Grille MountingBracket(s)

Sheet

Metal

Screws

Figure 16-3

12" Right FrontAccess Panel

Renewable Media

Hex HeadFasteners

Hex HeadFasteners

Hex HeadFasteners

StructuralFrame


GeneralThe AAF Model AED and AEQ units are air-to-airheat pumps and not dependent upon a central-ized heating system. Heat pumps extract heat fromcold outside air, amplify it, and transfer it to theoccupied space. This process drastically reducesthe need for electric resistance heating, thusconserving precious fossil fuels and minimizingenergy costs.

The heat pump cycle for the Models AED andAEQ units are designed to supply all the heatingneeds of the occupied space regardless of outdoortemperature. Optimal energy savings is obtainedwhen outdoor temperatures range from 65˚Fto 30˚F (18˚C to -1˚C). However, considerablesavings can be realized by operating the heat pumpcycle when subzero temperatures exist.

When the outdoor temperature is below 20˚F(-71˚C), the electric resistance heaters are able tobe energized. They will be energized only if theroom temperature setpoint cannot be satisfied bythe heat pump cycle alone. Should electric heatbecome necessary, it is energized in stages. Thiseliminates wide temperature swings that wouldoccur if an unnecessary amount of electric heat isenergized. Once the room temperature setpoint issatisfied, the electric heaters are de-energized instages until the desired room temperature canbe maintained.

The electric heat elements can also be energizedmanually by the “emergency heat switch.” Thisfeature is included to provide emergency heat inthe case of a compressor malfunction. Once themalfunction is repaired, the emergency heat switchshould be replaced in the “normal” position toallow regular heat pump operation to resume.

Defrost cycleThe heat pump cycle is designed to extract as much“free” heat out of the air as possible. The ModelAED and AEQ units are furnished with a defrostcycle to melt away any frost which may form onthe outdoor coil that could hinder normal heatpump operation.

A coil mounted sensor is used to activate thisdefrost cycle. The defrost cycle is factory set toenergize every 90 minutes depending on thecondition of the outdoor coil. If the sensordetermines the coil is too cold, it signals thereversing valve to reverse the flow of refrigerantsending hot gas through the frosted coil. Thisprocess occurs for a maximum of ten minutes.

During the defrost cycle, if the room requires heatto satisfy the thermostat setpoint, the electricresistance heaters are energized. These heaters arebrought on in stages until the desired roomtemperature is obtained. Once the coil is defrosted,the electric heat elements are de-energized and

Heat Pump Operation

Water Source Heat Pump Units – Models ARQ, ERQ

GeneralThe ARQ and ERQ Models are Self-containedWater Source Heat Pump Unit Ventilators. Theyare economical units which cool by removing heatfrom the room and transferring this heat to awater loop. Heating is accomplished by drawingheat out of the water loop and transferring it tothe room as warm air. Refrigerant is used toamplify this process allowing greater heat transferfor more efficient heating and cooling.

The ARQ and ERQ Models are designed andbuilt to serve commercial and industrial applicationssuch as schools, hospitals, office buildings and otherbuildings with large conference rooms and commonareas. This unit is available in six sizes, ranging from2 to 41⁄2 tons (7 to 15.8 kW) cooling capacity.

The ARQ and ERQ Models have outstandingventilation characteristics allowing up to 100%outside air to be introduced to the space. It con-tains a built-in refrigeration section that elimi-nates the need for chillers and outdoor condens-ing units making the ARQ and ERQ Models eco-nomical for new or retrofit construction.

Heating Cooling ProcessWater source heat pumps are a very efficientmethod of heating and cooling. When one unitis rejecting heat into the water loop, another unitis drawing heat from the water loop. The unitsare installed on a closed water loop using inter-connecting pipe. With a water source heat pumpsystem it is possible, and even desirable, to havemany units cooling at the same time that others

the heat pump heating cycle is resumed. This cycleoccurs every 90 minutes if defrost is required. The90-minute timer can be field adjusted to either45-minute or 30-minute cycles if necessary.

However, regardless of the cycle time, defrost willnot occur unless the outdoor coil sensor deter-mines the coil temperature is too low.

Condensate removalHeat pumps can generate condensate whileheating which must be disposed of properly.Condensate is produced mainly during the defrostcycle when refrigerant is reversed through theoutdoor coil to melt the frost or ice that is present.The Model AEQ is supplied with a drainconnection that can be attached to the building’sinternal collection system for disposal.A self-contained condensate disposal system is alsooffered for the AED Model. Condensate istransferred to a compartment that contains anelectric element designed to completely boilawayall heat pump condensate. This systemaccomplishes condensate disposal while simulta-neously adding much needed humidity to theoccupied space.

The Model AED and AEQ Self-contained Air-to-Air Heat Pump Unit Ventilators can providethe lowest energy usage of any Self-contained UnitVentilator available.

are heating. Cooling will occur in rooms that havedirect sunshine or a large number of occupants.Heating may be required in rooms with no sunsuch as north facing rooms and in unoccupiedspaces.

There are times, however, when every unit willrequire heating or every unit will requirecooling. For this situation, water source heatpumps usually include a cooling tower to rejectexcessive or unwanted heat. They will alsoemploy a central boiler for supplemental heat orseparate unit mounted electric resistance heatingcoils to add heat when the loop water tempera-ture becomes too low to extract heat.

Air-To-Air Heat Pump Units – Models AED, AEQ


LOUVER(NOTE 2)

STEEL LINTEL(BY OTHERS)

28"(711mm)

165⁄8"(422mm)

SEENOTE 1

WALLSLEEVE

CAULKPERIMETER

3" (76mm)

3"(76mm)

FLOOR

LOUVER(NOTE 2)

STEEL LINTEL(BY OTHERS)

165⁄8"(422mm)

CAULK PERIMETER)

WALLSLEEVE

28"(711mm)

3" (76mm)

3" (76mm)

FLOOR(INCLUDING CARPET)

LOUVER(NOTE 2)

28"(711mm)

165⁄8"(422mm)

28"(711mm)

CAULK PERIMETER

WALLSLEEVE

3" (76mm)

3" (76mm)

FLOOR

C

Notes:� Horizontal splitter (by others) must be installed whenever there is any space

beween the wall sleeve and the louver. It is also necessary to seal the ends ofthe wall opening.

� The top and two sides of the louver must be caulked watertight. Do not caulkbottom edge of louver. Refer to installation instructions in IM 502 for details.

DIMENSIONS IN INCHES (MM)UNIT ROOM PROJ. AMOUNTSIZE A L C END PANEL IN WALLDEPTH

0 165⁄8 (422) 113⁄8 (289)24 86 84 3 (76) 195⁄8 (498) 83⁄8 (213)30 (2184) (2134) 51⁄4 (133) 217⁄8 (557) 61⁄8 (156)

113⁄8 (289) 28 (711) 00 165⁄8 (422) 113⁄8 (289)

36 98 96 3 (76) 195⁄8 (498) 83⁄8 (213)40 (2489) (2434) 51⁄4 (133) 217⁄8 (557) 61⁄8 (156)

113⁄8 (289) 28 (711) 0

440 165⁄8 (422) 113⁄8 (289)

48110 108 3 (76) 195⁄8 (498) 83⁄8 (213)

54(2794) (2743) 51⁄4 (133) 217⁄8 (557) 61⁄8 (156)

113⁄8 (289) 28 (711) 0

Unit Cross Section – AZS, AZQ, AZR, AED, AEQ

� RACEWAY FOR FACTORY WIRING

� ELECTRIC HEAT CONTROL BOX

� EVAPORATOR COIL

� ELECTRIC HEATING COIL

� CONDENSING COIL

� OUTDOOR FANS

� INDOOR FANS

� Louvers may be recessed a maximum of 2" (51mm) from the exterior face of the wall.� Drain must be flush with floor to allow unit installation and removal. Unit drain

tube is 7⁄8" (22mm) O.D. copper.� A field supplied air seal should be applied to the exterior perimeter of the wall

sleeve when unit is installed with no recess.

Figure 18-1Full Recess

Figure 18-2Partial Recess

Figure 18-3No Recess (SEE NOTE 5)

TopView

FrontView

Application Considerations

Table 18-1. AZS, AZQ, AZR, AED, AEQ

Details and DimensionsAir Cooled Models AZS, AZQ, AZR, AED, AEQ

Figure 18-4. Cooling Mode

28"(711mm)

16 5⁄8"(422mm)

30"(762mm)

28"(711mm)

�

�

�

�

��

28"(711mm)

16 5⁄8"(422mm)

30"(762mm)

28"(711mm)

�

�

�

�

��

Figure 18-5. Heat Pump/Heating Mode

OUTDOOR INDOOR OUTDOOR INDOOR

CondenserDischarge Air

CondenserSupply Air

OutsideAir

1" (25mm)

121⁄8"(314mm)

111⁄2"(292mm)

Area For CondensateFloor Drain (See Note 4)

L

Wall Sleeve Location

Room Projection

C

Hinged Door (Control Access)

Area For Electric Wiring

51⁄2"(140mm)

1" (25mm)

63⁄8"(162mm)

5"(127mm)

26"(711mm)

165⁄8"(422mm)

1"(25mm)

EndPanel

1"(25mm)

EndPanel

A

RemovableDecorator Panels

30"(762mm)


� RACEWAY FOR FACTORY WIRING� ELECTRICAL JUNCTION BOX� AIR-TO-REFRIGERANT COIL� (OPTIONAL) ELECTRIC HEAT/COIL

(BOILERLESS ONLY)� WATER-TO-REFRIGERANT COIL

BRAZED PLATE HEAT EXCHANGERLOCATED IN LEFT END COMPARTMENT

Unit Cross Section – ARQ, ERQ

16 5⁄8" (422mm)or

21 7⁄8" (557mm)

30" (762mm)

Outdoor AirReturn Air

� �

��

Details and DimensionsWater Source Heat Pump Models ARQ, ERQ

Component Location and Dimensions (165⁄8˝ Deep)

Top View6-1⁄4"

(159mm)

11-1⁄2"(292mm)

3⁄4"(19mm)

11-1⁄2"(292mm)

16-5⁄8"(422mm)

11"(279mm)

6"(152mm) 17-1⁄2"

(445mm)

4

2

1

3

7

65

8

5

14"(356mm)

13-1⁄4"(337mm)

30"(762mm)

11"(279mm)

22-1⁄2" (572mm)23" (584mm)

7⁄8" (22mm) O.D.Copper Drain

Left-hand Standard Field Reversible

Return Water 3⁄4" (19mm) FPT

Supply Water 3⁄4" (19mm) FPT

A

F

G

H

1"(25mm)

1"(25mm)

5"(127mm)

3"(76mm)

27⁄8"(73mm)

3"(76mm)

E

Left End View Front View Right End View

Piping & Wall Thermostat Wiring:� Bottom entry within 11" x 111⁄2" (279 mm x 292 mm) area.Electrical — Main Power & Control Wiring:� Bottom entry within 6" x 111⁄2" (152 mm x 292 mm) area.� 1" (25.4 mm) and 2" (51 mm) knockouts in main junction box for main

power wiring.Component Location:� Hinged 24" x 143⁄4" (610 mm x 375 mm) access door.� Fan motor� Electrical control box� Compressor compartment� Compressor

ARQ-024, 030 ARQ-036, 040 ARQ-048, 054ERQ-024, 030 ERQ-036, 040 ERQ-048, 054

IN. MM IN. MM IN. MMA 86 2184 98 2489 110 2794B 48 1219 60 1524 72 1829D 55 1397 67 1702 79 2007E 51⁄5 132 51⁄5 132 7 178F 31⁄4 83 31⁄4 83 31⁄4 83G 1015⁄16 278 1015⁄16 278 17 432H 14 356 14 356 8 203

Table 19-1


Outdoor Air Arrangement — 165⁄8" (422mm) deep units

Details and Dimensions Water Source Heat Pump Models ARQ, ERQ (Continued)

Figure 20-2. Closed Pipe Tunnel (165⁄8˝ Deep)

Rear View (Without End Panels)

Right End View(Without End Panel)

C

11⁄2"(38mm)

13"(330mm)

25" (635mm)

30"(762mm)

19"(483mm)

4"(102mm)

D

Left End View(Without End Panel)

1" (25mm)

ARQ-024, 030 ARQ-036, 040 ARQ-048, 054ERQ-024, 030 ERQ-036, 040 ERQ-048, 054

IN. MM IN. MM IN. MMC 48 1219 60 1524 72 1829D 55 1397 67 1702 79 2007

Table 20-1

17"(165mm)

1" (25mm)

7" (178mm)

81⁄8"(206mm)

Outdoor Air Opening

1" (25mm) Air Seal

Resilient Insulationand Air Seal

If wall is chased, wallopening for outdoorair MUST BE WITHINTHE 28" x D (711mmx D) AREA.

28" x D(711mm x D)

81⁄2"(216mm)

4"(102mm)

6"(152mm)

165⁄8"(422mm)

Piping & Wall Thermostat Wiring:� Rear entry field cut in 4" x 177⁄8" (102 mm x 454 mm) area.

Electrical — Main Power & Control Wiring:� Rear entry field cut in 4" x 6" (102 mm x 152 mm) area.

Component Location:� Four 7⁄8" (22 mm) diameter holes in back for anchoring unit to wall.

2

3

3

1

131⁄2"(343mm)

61⁄2"(165mm)

177⁄8"(454mm)

29"(737mm)


Outdoor Air Arrangement — 217⁄8" (566mm) deep units

Table 21-1

Unit Size DimensionsC D

024 &

030

036 &

042

048 &

060

in.

mm

in.

mm

in.

mm

48 55

1219 1397

60 67

1524 1702

72 79

1829 2007

Outdoor AirDuct Collar

[5-1⁄4" (133mm) x B]Arrangement H

Rear View (Without End Panels)Left End View(Without End Panel)


13-1⁄2"(343mm)

30"(762mm)

17"(165mm)

19"(483mm)

23" (534mm)

Air Seal

C

4"

1-1⁄2"(38mm)11"

(279mm)

3"(76mm)

17-7⁄8"(454mm)

7"(178mm)

1-3⁄4" (44mm)11-3⁄4"

(298mm)

14"(356mm)

21-7⁄8" (556mm)3-1⁄4"

(83mm)1" (25mm)

6"1"

(25mm)

27-1⁄2" (699mm)

Outdoor AirOpening

1"(25mm)

4"(102mm)

11

11

4

2

B5-1⁄4"(133mm)

1⁄4" (6.4mm)

27-1⁄2" (699mm)x C area forOutdoor Air

Arrangement G

1"(25mm)

Piping Tunnel[1-3⁄4" x 11-3⁄4"(44 x 298mm)]Isolated from

Outdoor Air

1"(25mm)

1"(25mm)

6-1⁄2"(165mm)

Rear View (Without End Panels)

Left End View(Without End Panel)


11

11

4

2

C1-1⁄2"

(38mm)11"(279mm)

3"(76mm)

17-7⁄8"(454mm)1"

(25mm)

1" (25mm)

1"(25mm)

Air Seal

1"(25mm)

17"(165mm)

23" (534mm)

13-1⁄2"(343mm)

30"(762mm)

19"(483mm)

6-1⁄2"(165mm)

1"(25mm)

4"(102mm)

7"(178mm)

4"

Outdoor AirOpening12"

(305mm)14"

(356mm)

21-7⁄8" (556mm)

3-3⁄4" (95mm)2-1⁄2" (64mm)

14-1⁄2"(368mm)

10"

5-1⁄4" (133mm)

14-1⁄2"(368mm)

12" (305mm) x CArea For

Outdoor Air

Piping Area

6"

Piping & Wall Thermostat Wiring:➀ Bottom entry within 11" x 111⁄2" (279 mm x 292 mm) area.➁ Rear entry field cut in 4" x 177⁄8" (102 mm x 454 mm) area.Electrical — Main Power & Control Wiring:➂ Bottom entry within 6" x 111⁄2" (152 mm x 292 mm) area.

Rear entry field cut in 4" x 6" (102 mm x 152 mm) area.➄ 1" (25.4 mm) and 2" (51 mm) knockouts in main junction box for main

power wiring.Component Location:

Hinged 24" x 143⁄4" (610 mm x 375 mm) access door.Fan motor

➇ Electrical control box➈ Compressor compartment➉ Compressor

Four 7⁄8" (22 mm) diameter holes in back for anchoring unit to wall.Hinged 12" x 143⁄4" (305mm x 375mm) access door (Optional.)

6

7

4

11

12

Details and Dimensions Water Source Heat Pump Models ARQ, ERQ (Continued)

Figure 21-1. Partial Adaptor Back (217⁄8" Deep)

Figure 21-2. Full Adaptor Back (217⁄8" Deep)


Application ConsiderationsWater Source Heat Pump Models ARQ, ERQ

Figure 22-1. Standard UnitStandard Intake Louver Location

Figure 22-2. Chased Wall UnitTop of Intake Louver up to21" (533mm) Above Floor(With Adapter Back Available as an Accessory)

Figure 22-3. Chased Wall UnitTop of Intake Louver up to28" (711mm) Above Floor(With Adapter Back Available as an Accessory)

165⁄8" (422mm) Deep Unit

Important! Gasket sealingsurface is required.

Floor Line

Lintel(by others)

IntakeLouver

CementMortar

Pitch AwayFrom Unit

11⁄2" (38mm)


Floor Line

Lintel(by others)

IntakeLouver

CementMortar

Pitch AwayFrom Unit

11⁄2" (38mm)

Not LessThan 3"(76mm)

Not MoreThan 21"(533mm)


Floor Line

Lintel(by others)

IntakeLouver

CementMortar

Pitch AwayFrom Unit

11⁄2" (38mm)

Not LessThan 3"(76mm)


217⁄8" (556mm) Deep Unit

Figure 22-4. Pipe Passage UnitStandard Intake Louver Location(With Adapter Back Available as an Accessory)

Figure 22-5. Full Adapter Back UnitTop of Intake Louver up to28" (711mm) Above Floor(With Adapter Back Available as an Accessory)

Figure 22-6. Window Intake UnitWindow Intake Louver(With Adapter Back Available as an Accessory)


Floor Line

Lintel(by others)

IntakeLouver

CementMortar

Pitch AwayFrom Unit

11⁄2" (38mm)Not MoreThan 12"(305mm)

Important!Gasketsealing

surface isrequired.

Floor Line

Lintel(by others)

IntakeLouver


Floor Line

IntakeLouver

Window Sash

“Goose Neck” Duct(by others)

Duct Collar(AAF)


General — Furnish and install where shown onplans, a complete self-contained, air cooled,heating and cooling unit ventilator. This unit shallmeet capacities, airflow and configuration asshown on unit schedule.

Each standard unit must be listed by UnderwritersLaboratories Inc. (U.L.) as complying with allsafety standards.

The units shall ship fully assembled with theexception of the end panels which shall be pack-aged separately to allow easy access for piping andelectrical rough-in. (Option: Wall sleeves shall beshipped in advance of unit for rough-in.)

Unit construction — All internal sheet metalparts subject to corrosion must be made of galva-nized steel. The entire frame must be weldedconstruction to provide strength and rigidity.Frames assembled with sheet metal fasteners arenot acceptable.

Cabinets — Exterior cabinet panels shall beconstructed of heavy-gauge steel and every exposedcorner must be welded and ground smooth forappearance and durability. All surfaces shall becleaned and phosphatized, then painted with anoven baked powder paint. Top surface shall beCharcoal Bronze textured powder paint to resistscratching and hide fingerprints. Front accesspanels and top access door shall be supplied withtamper resistant fasteners.

Removable discharge grille shall be constructed ofcontinuous, round edged, steel bars to provide a10-degree vertical deflection.

Adjustable side deflection vanes shall be providedbeneath the discharge grille to give optimallateral air distribution.

(Option: A 1⁄4" (6mm) mesh screen shall beprovided beneath the discharge grille to protectagainst objects being dropped through thedischarge grille.)

Room air fans and motor — The motor andfan assembly shall be low speed design and shallbe double inlet, forward curved centrifugal typewith maximum fan speed of 1100 rpm. Fan wheelsshall be constructed of dark, high density, injec-tion molded polypropylene having high impactstrength, chemical resistance and thermal stabil-ity. Assembly shall be direct drive type and shall

SpecificationsAir Cooled Units

be statically and dynamically balanced. Motor shallbe permanent split capacitor (PSC) plug-in typelocated out of the airstream and have an internalthermal overload device (auto-reset). Fan speedsshall be controlled by High-Med-Low-Off switch.Fan/coil arrangement shall be draw-thrudesign for uniform coil face velocity and dischargeair temperature.

Fan motors and controls shall have each hot lineprotected by factory installed cartridge type fuse(s)The unit manufacturer shall provide one (1) sparemotor for each size and type of motor furnishedas part of a unit ventilator, except units havingdouble extended shaft motors shall be providedwith one (1) spare fan board assembly for eachunit size.

All components of the fan/motor assembly shallbe removable from the front of the unit. Themotor and fan shaft shall have sleeve type bearingswith precision tolerances and shall not requireoiling more than once annually.

Condenser fans and motors — The fanboard and fan housings shall be constructed ofgalvanized steel. The fan motor and fan shaft shallhave permanently lubricated ball bearings. Motorshall be permanent split capacitor (PSC) type. Fanwheels shall be forward curved centrifugal type.

Outdoor/room air dampers — Each unitshall be provided with separate room air and out-door air dampers. The room air damper shall beconstructed of aluminum and counterbalancedagainst back pressure. Outdoor air damper shallbe two-piece, double wall construction with 1⁄2"(13mm) thick, 1.5 lbs. (.68 kg) density fiberglassinsulation sandwiched between welded galvanized-steel blades. Outdoor air damper shall haveadditional foam insulation on the exterior of theblades and end partitions. Dampers shall befitted with blended mohair seals along all sealingedges. Damper bearings shall be made of nylon orother material which does not require lubrication.

Refrigeration system — The refrigerationsection shall be constructed of galvanized steel andshall include a factory sealed, factory piped assemblyconsisting of a hermetically sealed compressor withan integral crankcase heater, a condenser coil,condenser fan and motor, and an evaporator coil.No condensate drain piping system shall berequired as the cooling condensate is to bedisposed of by directing it into the condenser fan

scrolls for re-evaporator on the hot condenser coil.The equipment manufacturer is to be fully respon-sible for the integrity of the refrigerant pipingand the entire refrigeration circult, includingcompressor. Condenser and evaporator coils shallbe fully assembled and tested prior to shipment.The motor compressor unit shall be vibrationisolated internally and externally and shall beconnected in such a manner as to prevent trans-mission of vibration to other components withinthe section.

Single-phase only: Single-phase units shallhave permanent split capacitor (PSC) compressormotor with start assist consisting of a compressorstart capacitor and compressor start relay.

Units with three-phase power: Shallutilize three-phase compressors for balancedelectrical compressor loads.

The condenser coil shall be constructed of coppertubes mechanically expanded to embossed alumi-num plate fins. The unit shall be so designed as toallow access to the entering side of the condensercoil for cleaning without opening the sealedrefrigeration circuit. The evaporator coil shall beconstructed of copper tubing having embossedaluminum plate fins mechanically bonded theretoand shall be positioned above an insulated galva-nized steel drain pan.

Refrigerant (R-22) shall be metered by a thermo-static expansion valve in lieu of capillary tubingto achieve evaporator performance and to protectthe compressor from floodback of liquid refrigerant.The refrigerant section shall be adequatelyinsulated to prevent “sweating.”

The unit shall be furnished and wired withcompressor thermal/current overload and highpressure cutout. Gauge ports shall be provided toallow reading of refrigerant pressures at thesuction and discharge of the compressor.Compressor shall be equipped with internalpressure relief valve to protect against excessivepressure buildup.

[Optional] Electric coils — Heating elementsshall be of the open wire type. Electric heat shallbe controlled in [two] [three] stages. A capillarytype high limit thermostat shall be provided todisconnect the heating elements through backupcontactors if an overheat condition is detected.A front panel interlock switch shall be furnished

Models AZS, AZQ, AZR



Specifications Air Cooled Units (Continued)

to de-energize the electric resistance heatingelement when center front panel is opened.

[Optional] Hot water coil — Coil shall bealuminum plate fin and copper tube construction.Coil shall be suitable for 150 psi workingpressure. Coil shall be provided with an accessiblemanual air vent at the high point of the coil and athreaded drain plug at the low point of the coil.

Contractor shall provide all necessary balancingvalves, shutoff valves and union connections inboth the supply and return piping connections topermit removal of the unit from the wall sleevefor servicing.

[Option: Coil shall be controlled by a 3-way(optional 2-way) modulating control valve andshall be factory wired by the unit ventilatormanufacturer. Valve shall be field installed andpiped by the installing contractor.]

— OR —

[Option: Coil shall be controlled by a modulatingface and bypass damper. Coil shall have a 3-way,2-position, end-of-cycle valve to shut off water flowwhen heating is no longer required. Valve and coilreturn shall have union connections. Valve shallbe factory wired by the unit ventilator manufac-turer and shall be field installed and piped by theinstalling contractor.]

(Optional) Steam coil — Coil shall be alumi-num plate fin and copper tube construction. Coilshall be double tube (DT) steam distributing,freeze resistant type. Coil shall be pitched toinsure complete condensate removal for freezeprotection and elimination of “water hammer.”

Contractor shall provide all necessary shutoff valvesand union connections in both the supply andreturn piping connections to permit removal ofthe unit from the wall sleeve for servicing.

A pressure equalizing device (vacuum breaker) shallbe factory installed to prevent the retention ofcondensate in the coil. The installing contractorshall connect the device to the return line beyondthe trap using the tubing provided. Steam trapshall be furnished and field installed by theinstalling contractor.

[Option: Coil shall be controlled by a 2-way,modulating control valve and shall be factory wired

by the unit ventilator manufacturer. Valve shallbe field installed and piped by the installingcontractor.]

— OR —

[Option: Coil shall be controlled by a modulatingface and bypass damper. Coil shall have a 2-way,2-position, end-of-cycle valve to shut off steamwhen heating is no longer required. Valve and coilsupply shall have union connections. Valve shallbe factory wired by the unit ventilator manufac-turer. Valve shall be field installed and piped bythe installing contractor.)

[Optional] Up-feed piping.

[Option: Up-feed piping stub-up within the unitend compartment requires the installing contractorto furnish union connection at the floor line inthe supply and return lines with shutoff valvesbelow the floor line. This is required to permitunit installation and removal for servicing.]

[Option: Up-feed piping stub-up shall be broughtup external to the unit within a removable 6",(152mm) wide end panel. The shutoff valves andunion connections shall be located within the 6"(152mm) wide end panel.]

Filter — Filter shall be one-piece design locatedto provide filtration of the outdoor air/returnairflow. Separate filters for outdoor air and returnair are not acceptable. Throwaway filter shall befactory furnished initially installed in the unit.

[Option: Furnish _____________ extra set(s) ofthrowaway filters.]

[Option: Furnish one set of wire mesh permanentfilters as final filter.]

[Option: Furnish one set of renewable (metalframe with glass fiber media) filters as final filter.]

[Option: Furnish _____________ roll(s) ofrenewable filter media.]

Acoustical treatment — The compressor shallbe mounted on neoprene compressor isolators forexternal vibration isolation. Compressor enclosurepanels shall be 16-gauge minimum andcrossbroken for additional rigidity to dampenvibration. Compressor enclosure panels and unitfront panel (compressor end) shall have 11⁄2 lbs.

(.68 kg) minimum density, 1" (25mm) thick glassfiber insulation and felt type material affixed tothe interior surfaces to dampen the compressorsound. Unit shall have attenuating loops inboth the suction and discharge lines to reducemechanical vibration.

[Optional] Acoustical package — Thecompressor shall be mounted on neoprenecompressor isolators for external vibration isolation.Sound attenuating loops and seamless flexiblebronze hose vibration absorbers shall be furnishedin both the suction and discharge lines to reducemechanical vibration.

Compressor enclosure panels shall be 16-gaugeminimum and crossbroken for additional rigidityto dampen vibration. Complete interior ofcompressor compartment shall be lined with amulti-functional material that serves as a soundbarrier, an absorber of sound and also must act asa decoupler to the compressor enclosure. Thismulti-functional material shall have a mylar coatingon the face to act as a sound reflector and toincrease the strength of the material. Dampingmaterial shall be textured foam type.

The exterior of the compressor compartment shallbe coated with a high density damping materialto eliminate impact noise and vibration. The rightend panel, right-hand front panel, 36" (914mm)of the right-hand end of the center front panel andthe hinged top access door shall be coated with a highdensity material to eliminate noise and vibration.

[Option: If the unit has no right-hand end paneland has a cabinet abutting the right end, adhesivebacked high density damping material shall befurnished for field installation by the Installingcontractor.]

Temperature controls — The unit ventilatormanufacturer shall provide factory installed,calibrated, and tested temperature controls. Unitsthat are capable of providing up to 100% outsideair shall provide a microprocessor-based DirectDigital Control (DDC) that can monitor condi-tions and automatically adjust unit operations tomaintain these requirements. This DDC controlshall have the following tenant adjustments: (1)room temperature setpoint, (2) minimum percentoutdoor air setting, and (3) unoccupied setpoint(offset). An LED status/fault indicator shall befurnished for inspection and a communicationsport shall be incorporated to allow manipulation



Specifications Air Cooled Units (Continued)

by a remote PC. The remote PC shall be able toaccess and change pertinent operating aindroom conditions from a remote location. Themicroprocessor-based control must be capable ofcommunicating to a local IBM-compatible PCusing the RS-232 protocol. When using thisremote PC, the unit must be capable of reactingto changes made by the remote PC. The remotePC must also be able to access all pertinentoperating and room conditions.

Room temperature sensorand tenant override options

Unit-mounted — Units shall have a tempera-ture sensor located in a sampling chamber toallow a constant circulation of room air to flowacross the sensing device. The sampling chambershall be designed in such a manner that willensure rapid and accurate sensing of room air.[Option: A unit mounted tenant override deviceshall be supplied.]

Wall-mounted sensor — Units shall have atemperature sensor with status LED funnished formounting to the wall. [Option: In addition, atenant override switch shall be furnished as partof the wall mounted sensor.]

Wall-mounted sensor with tenant over-ride and setpoint adjustment — A sensorwith integral tenant override and status LED shallbe furnished with the unit ventilators. This sensorshall also contain a manually adjustable tempera-ture setting allowing the controller setpoint to beincreased or decreased by 3°F (2°C).

Wall sensor with setpoint adjustment —Units shall have a sensor furnished with a manu-ally adjustable temperature setting allowing thecontroller setpoint to be increased or decreasedby 3°F (2°C).

[Optlonal] Ventilation lockout relay —Units that are not on network control shall befurnished with a [24V] [120V] ventilation lock-out relay to permit closing the outdoor damperduring normal occupied operation. Outdoor airdamper shall close when the relay is energized bya [24V] [120V] signal.

[Optional] Exhaust fan interlock relay —Each unit shall be furnished with an exhaust faninterlock relay. When energized by a [24V] [120V]external signal, the outdoor air damper shall move

to the 100% outdoor air position and shallremain fully open.

[Optlonal] Night control with unit day/night switch (stand-alone units only) —Each unit (except slaves) shall be furnished with aunit mounted day/night switch to permit manualindexing from day to “night” mode. For units with100% O.A. capability, the unoccupied offsettemperature setpoint(s) shall be in force whenindexed to the “night” mode. The outdoor airdamper shall remain closed at all times during the“night” mode.

[Optional] Night control with unit-mountedtime clock — Each unit shall be furnished witha unit-mounted, field programmed time clock forday/night changeover. This clock shall have abattery backup that will provide up to 150 hoursof operation during a power outage. A unit-mounted holiday switch shall be furnished toallow manual changeover to unoccupied control forextended or otherwise unscheduled periods.

Wall sleeve — The galvanized steel, one-piecewall sleeve shall be set In a wall opening and buttedup directly against the intake louver. Where it isnot possible to butt the wall sleeve against the wallintake louver, the contractor shall fabricate andinstall a horizontal sheet metal baffle betweenlouver and wall sleeve to provide an airtightseparation between condenser discharge andreturn air. The wall sleeve is to be permanentlyfastened in place and shall be suitably sealed,caulked or grouted by the contractor around theentire perimeter to prevent air leakage.

The wall sleeve shall be fitted with an electricaljunction box containing a main “on-off” switch.All field wiring connections shall be made in thiswall sleeve junction box.

(It shall be the installing contractor’s responsibilityto make the final load side power wiring connec-tions between the wall sleeve junction box and theunit terminal block (including the wiring goingto the electric heating elements.The wall sleeveshall be cartoned separately and shipped to thejobsite preceding the unit ventilator. Junction boxshall ship separately for field installation.)

Wall intake Louver — The louver shall be sup-plied by the unit manufacturer and shall be ofheavy-gauge (unpainted, painted, or clear anod-ized) aluminum construction. The louver shall be

of the [vertical blade] [horizontal blade] type andshall be divided in half horizontally across the lou-ver to prevent condenser air recirculation. A 1⁄2"(13mm) square mesh bird screen shall be providedon the backside of the wall intake louver. All lou-vers shall be 28" (711mm) high by 21⁄4"(57mm)thick and suitable for both masonry and panel wallconstruction. The frame of the louver shall haveweep holes along the bottom. Lintels shall be pro-vided by the contractor above the louver opening.

(Optional: Heavy-duty lattice grille horizontal andvertical lines shall “line up” with the louver bladesto present an aesthetic appearance. Grille shall befabricated from mill finish aluminum. The standardaluminum allow shall be [unpainted] [painted][clear anodized].)


General — Furnish and install where shown onplans, a complete self-contained, air-to-air heatpump unit ventilator. This unit shall meet capaci-ties, airflow and configuration as shown on unitschedule.

Each standard unit must be listed by UnderwritersLaboratories Inc. (U.L.) as complying with allsafety standards.

The units shall ship fully assembled with theexception of the end panels which shall be pack-aged separately to allow easy access for piping andelectrical rough-in. (Wall sleeves shall be shippedin advance of unit for rough-in.)

Unit construction — All internal sheet metalparts subject to corrosion must be made of galva-nized steel. The entire frame must be weldedconstruction to provide strength and rigidity.Frames assembled with sheet metal fasteners arenot acceptable.

Cabinets — Exterior cabinet panels shall beconstructed of heavy-gauge steel and every exposedcorner must be welded and ground smooth forappearance and durability. All surfaces shall becleaned and phosphatized, then painted with anoven baked enamel. Top surface shall be CharcoalBronze textured baked enamel to resist scratchingand hide fingerprints. Front access panels and topaccess door shall be supplied with tamper resis-tant fasteners.

Removable discharge grille shall be constructed ofcontinuous, round edged, steel bars to provide a10-degree vertical deflection. Adjustable sidedeflection vanes shall be provided beneath thedischarge grille to give optimal lateral airdistribution.

(Option: A 1⁄4" (6mm) mesh screen shall beprovided beneath the discharge grille to protectagainst objects being dropped through thedischarge grille.)

Room air fans and motor — The motor andfan assembly shall be low speed design and shallbe double inlet, forward curved centrifugal typewith maximum fan speed of 1100 rpm. Fan wheelsshall be constructed of dark, high density, injec-tion molded polypropylene having high impactstrength, chemical resistance and thermal stability.Assembly shall be direct drive type and shall bestatically and dynamically balanced. Motor shall

SpecificationsAir-to-Air Heat Pump UnitsModels AED, AEQ

be permanent split capacitor (PSC) with speedscontrolled by High-Off-Low switch. Fan/coilarrangement shall be draw-thru design foruniform coil face velocity and discharge airtemperature.

Motors shall be permanent split capacitor (PSC),plug-in type located out of the airstream and havean internal thermal overload device (auto-reset).

Fan motors and controls shall have each hot lineprotected by factory installed cartridge type fuse(s)The unit manufacturer shall provide one (1) sparemotor for each size and type of motor furnishedas part of a unit ventilator, except units havingdouble extended shaft motors shall be providedwith one (1) spare fan board assembly for eachunit size.

All components of the fan/motor assembly shallbe removable from the front of the unit. Themotor and fan shaft shall have sleeve type bear-ings with precision tolerances and shall not requireoiling more than once annually.

Condenser fans and motors — The fanboard and fan housings shall be constructed ofgalvanized steel. The fan motor and fan shaft shallhave permanently lubricated ball bearings. Motorshall be permanent split capacitor (PSC) type. Fanwheels shall be forward curved centrifugal type.

Outdoor/room air dampers — Each unitshall be provided with separate room air and out-door air dampers. The room air damper shall beconstructed of aluminum and counterbalancedagainst back pressure. Outdoor air damper shallbe two-piece, double wall construction with 1⁄2"(13mm) thick, 1.5 lbs. (.68 kg) density fiberglassinsulation sandwiched between weldedgalvanized-steel blades. (Option: “Cold weather”outdoor air damper shall have additional foaminsulation on the exterior of the blades and endpartitions.) Dampers shall be fitted with blendedmohair seals along all sealing edges. Damper bear-ings shall be made of nylon or other material whichdoes not require lubrication.

Refrigeration system — The refrigerationsection shall be constructed of galvanized steel andshall include a factory sealed, factory piped assem-bly consisting of a hermetically sealed compressorwith an integral crankcase heater, a condenser coil,condenser fan and motor, and an evaporator coil.No condensate drain piping system shall be

required as the cooling condensate is to bedisposed of by directing it into the condenser fanscrolls for re-evaporator on the hot condenser coil.The equipment manufacturer is to be fully respon-sible for the integrity of the refrigerant piping andthe entire refrigeration circult, including compres-sor. Condenser and evaporator coils shall be fullyassembled and tested prior to shipment. Themotor compressor unit shall be vibration isolatedinternally and externally and shall be connectedin such a manner as to prevent transmission ofvibration to other components within the section.

Single-phase only: Single-phase units shallhave permanent split capacitor (PSC) compressormotor with start assist consisting of a compressorstart capacitor and compressor start relay.

Units with three-phase power: Shall utilizethree-phase compressors for balanced electricalcompressor loads.

The condenser coil shall be constructed of coppertubes mechanically expanded to embossed alumi-num plate fins. The unit shall be so designed as toallow access to the entering side of the condensercoil for cleaning without opening the sealedrefrigeration circuit. The evaporator coil shall beconstructed of copper tubing having embossedaluminum plate fins mechanically bonded theretoand shall be positioned above an insulatedgalvanized steel drain pan.

Refrigerant (R-22) shall be metered by a thermo-static expansion valve in lieu of capillary tubingto achieve evaporator performance and to protectthe compressor from floodback of liquid refrigerant.The refrigerant section shall be adequatelyinsulated to prevent “sweating.”

The unit shall be furnished and wired withcompressor thermal/current overload and highpressure cutout. Gauge ports shall be provided toallow reading of refrigerant pressures at thesuction and discharge of the compressor.Compressor shall be equipped with internalpressure relief valve to protect against excessivepressure buildup.

Electric coils — Heating elements shall be ofthe open wire type. Electric heat shall be controlledin [two] [three] stages. A capillary type high limitthermostat shall be provided to disconnect theheating elements through backup contactors if anoverheat condition is detected. A front panel


interlock switch shall be furnished to de-energizethe electric resistance heating element whencenter front panel is opened.

Defrost control and defrost condensatedisposal — Defrost control shall be of thetime-temperature type. Defrost cycle shall beinitiated only at the factory set interval of 90minutes and only when the coil surface temperatureis below 28°F (-2°C). Defrost timer shall be fieldadjustable for 30-minute or 45-minute intervals.Unit shall include a thermostatically controlledelectric resistance heater for defrost condensatedrain pan. Heater shall be energized at 38°F (3°C)±5°F (±3°C) outdoor air temperature. Defrostcondensate shall be piped into a building drainsystem. [Option: Unit shall not require a heatingcondensate drain. A built-in method of heatingcondensate disposal shall be used which providesroom humidification.]

Emergency electric heat switch — Anemergency electric heat switch shall be furnishedto allow the unit to provide electric resistanceheating regardless of outdoor air temperature incase of compressor malfunction.

Filter — Filter shall be one-piece design locatedto provide filtration of the outdoor air/return air-flow. Separate filters for outdoor air and return airare not acceptable. Throwaway filter shall befactory furnished initially installed in the unit.





Acoustical treatment — The compressor shallbe mounted on neoprene compressor isolators forexternal vibration isolation. Compressor enclosurepanels shall be 16-gauge minimum andcrossbroken for additional rigidity to dampenvibration. Compressor enclosure panels and unitfront panel (compressor end) shall have 11⁄2 lbs.(.68 kg) minimum density, 1" (25mm) thick glassfiber insulation and felt type material affixed tothe interior surfaces to dampen the compressor

Models AED, AEQ

Specifications Air-to-Air Heat Pump Units (Continued)

sound. Unit shall have attenuating loops in boththe suction and discharge lines to reducemechanical vibration.

[Optional] Acoustical package —The compressor shall be mounted on neoprenecompressor isolators for external vibration isolation.Sound attenuating loops and seamless flexiblebronze hose vibration absorbers shall be furnishedin both the suction and discharge lines to reducemechanical vibration.

Compressor enclosure panels shall be 16-gauge minimum and crossbroken for additionalrigidity to dampen vibration. Complete interiorof compressor compartment shall be linedwith a multi-functional material that servesas a sound barrier, an absorber of sound andalso must act as a decoupler to the compressorenclosure. This multi-functional materialshall have a mylar coating on the face to act as asound reflector and to increase the strength ofthe material. Damping material shall be texturedfoam type.

The exterior of the compressor compartment shallbe coated with a high density damping materialto eliminate impact noise and vibration. The rightend panel, right-hand front panel, 36" (914mm)of the right-hand end of the center front paneland the hinged top access door shall be coatedwith a high density material to eliminate noise andvibration.

[Option: If the unit has no right-hand end paneland has a cabinet abutting the right end, adhesivebacked high density damping material shall befurnished for field installation by the installingcontractor.]

Temperature controls — The unit ventilatormanufacturer shall provide factory installed,calibrated, and tested temperature controls. Unitsthat are capable of providing up to 100% outsideair shall provide a microprocessor-based DirectDigital Control (DDC) that can monitorconditions and automatically adjust unitoperations to maintain these requirements. ThisDDC control shall have the following tenantadjustments: (1) room temperature setpoint, (2)minimum percent outdoor air setting, and (3)unoccupied setpoint (offset). An LED status/faultindicator shall be furnished for inspection and acommunications port shall be incorporated toallow manipulation by a remote PC. The remote

PC shall be able to access and change pertinentoperating aind room conditions from a remotelocation. The microprocessor-based control mustbe capable of communicating to a local IBM-compatible PC using the RS-232 protocol. Whenusing this remote PC, the unit must be capable ofreacting to changes made by the remote PC.The remote PC must also be able to access allpertinent operating and room conditions.

Units that have 20% maximum outdoor capabilityshall be furnished with a room thermostat that is[unit] [wall] mounted and shall be [manual][automatic] changeover type. The mechanicalcooling cycle shall be locked out whenever theoutdoor air termperature is below 50°F (10°C).



Wall-mounted sensor — Units shall have atemperature sensor with status LED furnished formounting to the wall. [Option: In addition, atenant override switch shall be furnished as partof the wall mounted sensor.]

Wall-mounted sensor with tenant over-ride and setpoint adjustment — A sensorwith integral tenant override and status LED shallbe furnished. This sensor shall also contain amanually adjustable temperature setting allowingthe controller setpoint to-be increased or decreasedby 3°F (2°C).

Wall sensor with setpoint adjustment —Units with 100% O.A. capability shall have asensor furnished with a manually adjustabletemperature setting allowing the controllersetpoint to be increased or decreased by3°F (2°C).

[Accessory] Ventilation lockout relay —Units that are not on network control shall befurnished with a [24V] [120V] ventilation lock-out relay to permit closing the outdoor damperduring normal occupied operation. Outdoor air


damper shall close when the relay is energized bya [24V] [120V] signal.

[Accessory] Exhaust fan interlock relay— Each unit shall be furnished with an exhaustfan interlock relay. When energized by a [24V][120V] external signal, the outdoor air dampershall move to the maximum outdoor air positionand shall remain fully open.

[Accessory] Night control with unit day/night switch (stand-alone units only) —Each unit (except slaves) shall be furnished with aunit mounted day/night switch to permit manualindexing from day to “night” mode. The unoccu-pied offset temperature setpoint(s) shall be in forcewhen indexed to the “night” mode. The outdoorair damper shall remain closed at all times duringthe “night” mode.

[Accessory] Night control withunit-mounted time clock — Each unitshall be furnished with a unit-mounted,field programmed time clock for day/night changeover. This clock shall have a batterybackup that will provide up to 150 hours ofoperation during a power outage. A unit-mounted holiday switch shall be furnished toallow manual changeover to unoccupied controlfor extended or otherwise unscheduled periods.

Wall sleeve — The galvanized steel, one-piecewall sleeve shall be set in a wall opening and buttedup directly against the intake louver. Where it isnot possible to butt the wall sleeve against the wallintake louver, the contractor shall fabricate andinstall a horizontal sheet metal baffle between louverand wall sleeve to provide an airtight separationbetween condenser discharge and return air. Thewall sleeve is to be permanently fastened in placeand shall be suitably sealed, caulked or grouted bythe contractor around the entire perimeter toprevent air leakage.


It shall be the installing contractor’s responsibilityto make the final load side power wiring connec-tions between the wall sleeve junction box and theunit terminal block (including the wiring goingto the electric heating elements.)(The wall sleeveshall be cartoned separately and shipped to the

Models AED, AEQ

Specifications Air-to-Air Heat Pump Units (Continued)

jobsite preceding the unit ventilator. Junction boxshall ship separately for field installations.)

Wall Intake Louver — The louver shall be sup-plied by the unit manufacturer and shall be ofheavy-gauge (unpainted, painted, or clear anodized)aluminum construction. The louver shall be of the[vertical blade] [horizontal blade] type and shallbe divided in half horizontally across the louverto prevent condenser air recirculation. A 1⁄2"(13mm) square mesh bird screen shall be providedon the backside of the wall intake louver. All louversshall be 28" (711mm) high by 21⁄4"(57mm) thickand suitable for both masonry and panel wall con-struction. The frame of the louver shall have weepholes along the bottom. Lintels shall be providedby the contractor above the louver opening.

(Optional: Heavy-duty lattice grille horizontal andvertical lines shall “line up” with the louver bladesto present an aesthetic appearance. Grille shallbe fabricated from mill finish aluminum. Thestandard aluminum allow shall be [unpainted][painted] [clear anodized].)


General — Furnish and install where shown onplans, with unit capacities and characteristics aslisted in schedule for self-contained water sourceheat pump console units.

This unit shall be listed by Underwriters Labora-tories Inc. (U.L.). Units shall bear the U.L. andcUL labels.

The unit shall be furnished with a main power“on-off” switch.

Cabinet — Cabinet shall have all welded galva-nized steel frame with an oven baked powder paintfinish. Color selected by architect frommanufacturer’s color chart. Top surface shall havean oven baked textured Charcoal Bronze finish toprovide superior durability, scuff resistance and lowreflectivity in lieu of smooth enamel. Front accesspanels and top access door shall be supplied withtamper resistant hex socket head threaded fasteners.Opening or removing the unit left- or right-handfront panels shall not affect unit operation inorder to facilitate testing and servicing. Internalsheet metal parts shall be constructed of galvanizedsteel to inhibit corrosion.

Unit discharge grille shall be constructed ofcontinuous round edged steel bars to provide10-degres vertical deflection. Adjustable sidedeflection vanes shall be provided beneath thedischarge grille to provide optimum lateral airdistribution. Cabinet depth shall not exceed 165⁄8"(422mm) [217⁄8" (566mm) if adapter back is used].[Option: A 1⁄4" (6mm) mesh screen shall beprovided beneath the discharge grille to protectagainst objects being dropped through thedischarge grille.]

Unit shall have glass fiber blanket insulation. Thisshall act as an outdoor air seal on 165⁄8 (422mm)deep units. Units that are 217⁄8" (566mm) deepshall also have glass fiber blanket insulation onthose adapter back parts which come In contactwith outdoor air. Units that are 217⁄8" (566mm)deep shall have a vinyl foam air seal which shallgo around the perimeter of the wall opening forthe wall intake louver.

Fan and Motor — The motor and fanassembly shall be low speed designed to assuremaximum quietness and efficiency. Fans shalldouble inlet, forward curved centrifugal type withmaximum fan speed of 800 rpm. Fan wheels shallbe constructed of dark, high density, injection

SpecificationsWater Source Heat Pump UnitsModels ARQ, ERQ

molded polypropylene having high impactstrength, chemical resistance and thermal stability.Assembly shall be statically and dynamicallybalanced. Fan housings shall be of steel construc-tion. Fan shaft shall be 11⁄4" (32mm) diameter,hollow steel with 11⁄4" (32mm) end bearing. Fanand motor assembly shall be direct drive type.

Motor speed shall be controlled by factoryfurnished and mounted multi-tap transformerthrough High-Off-Low switch.

Fan/coil arrangement shall be draw-thrudesign for uniform coil face velocity and dischargeair temperature In addition to providing thekinetic energy for optimum air distribution.

Motors shall be permanent split capacitor (PSC),plug-in type designed specifically for unit ventila-tor operation. Motors shall be located out of theairstream and have an internal thermal overloaddevice (auto-reset).

Fan motors and controls shall have each hot lineprotected by factory Installed cartridge type fuse(s).The unit manufacturer shall provide one (1) sparemotor for each size and type of motor furnishedas part of a unit ventilator, except units havingdouble extended shaft motors shall be providedwith one (1) spare fan board assembly for eachunit size.

All components of the fan/motor assembly shallbe removable from the front of the unit. Themotor and fan shaft shall have sleeve type bearingswith precision tolerances and shall not requireoiling more than once annually.

Outdoor/room air dampers — Each unitshall be provided with separate room air andoutdoor air dampers. The room air dampershall be constructed of aluminum and counter-balanced against back pressure to close by windpressure, thereby preventing outdoor air fromblowing directly into the room. Outdoor airdamper shall be two-piece, double wallconstruction with 1/2" (13mm) thick, 1.5 lbs. (.68kg) density fiberglass insulation sandwichedbetween welded between 20 gauge galvanized-steel blades for rigidity and to inhibit corrosion.[Option: “Cold weather” outdoor air damper shallhave additional foam insulation on the exteriorsurfaces of the damper blade and on the ends ofthe outdoor air chamber.]

Refrigeration system — The refrigerationsection shall be constructed of galvanized steel andshall include a factory sealed compressor, awater-to-refrigerant coil, and air-to refrigerant coiland reversing valve. The reversing valve shall havea replaceable external solenoid coil which isenergized only when space heating is required. Theequipment manufacturer is to be fully responsiblefor the integrity of the refrigerant piping and theentire refrigeration circuit, including compressor,water-to-refrigerant coil and air-to-refrigerant coil,shall be fully assembled and tested prior to shipment.

The motor compressor unit shall be vibrationisolated internally and externally and shall beconnected in such a manner as to prevent trans-mission of vibration to other components withinthe section.

Single phase only: Single phase units shall havepermanent split capacitor (PSC) compressormotor with start assist consisting of a compressorstart capacitor and compressor start relay.

The water-to-refrigerant coil shall be of either thecoaxial type with a copper convoluted inner tubeand a steel outer shell or stainless steel plate heatexchanger. Either type shall be constructed to besuitable for 300 lbs. (2069 kPa) water workingpressure and 450 lbs. (3104 kPa) refrigerant pressure.

Refrigerant (R-22) shall be metered by a thermo-static expansion valve In lieu of capillary tubingto achieve balanced evaporator performance andto protect the compressor from floodback of liquidrefrigerant.

The refrigerant section shall be adequately insu-lated to prevent “sweating.” The unit shall befurnished and wired with the following safetydevices: compressor thermal/current overloads andhigh pressure cutout switch. Gauge ports shall beprovided to allow reading of refrigerant pressuresat the suction and discharge of the compressor.

Condensate Pan — Insulated drain pan shallbe constructed of galvanized steel and shall bepositioned beneath the air-to-refrigerant coil.Drain connection shall be field reversible for left-or right-hand drain line.

Filter — Filter shall be one-piece type. Throw-away filter shall be factory furnished initiallyinstalled in the unit.






(Optional] Bollerless systems — Units shallutilize reverse cycle operation for heating until thewater loop temperature drops below 60°F (16°C),at which time the unit switches over to electricresistance heating. Heating elements shall be ofthe open wire type. Units have up to three stagesof electric heat. A capillary tube type high limitthermostat shall be provided to disconnect theheating elements through backup contactors if anoverheat condition is detected.

A front panel interlock switch shall be furnishedto de-energize the electric resistance heating coilwhe the center front socess panel is opened.

An emergency electric heat switch shall be furnishedto allow the unit to be manually switched to electricresistance heating in case the reverse cycle heatingsystem becomes inoperative. This shall permit theelectric resistance heaters to operate as needed re-gardless of loop water temperature.

Acoustical treatment — The compressor shallbe mounted on neoprene compressor isolators forexternal vibration isolation. Compressor enclosurepanels shall be 16-gauge minimum andcrossbroken for additional rigidity to dampenvibration. Compressor enclosure panels and unitfront panel (compressor end) shall have 11⁄2 lbs.(.68 kg) minimum density, 1" (25mm) thick glassfiber insulation and felt type material affixed tothe interior surfaces to dampen the compressorsound. Unit shall have attenuating loops in boththe suction and discharge lines to reducemechanical vibration.

[Optional] Acoustical package —The compressor shall be mounted onneoprene compressor isolators for externalvibration isolation. Sound attenuating loops andseamless flexible bronze hose vibration absorbersshall be furnished in both the suction and dischargelines to reduce mechanical vibration to the

Models ARQ, ERQ

Specifications Water Source Heat Pump Units (Continued)

outside of the compressor compartment throughthe refrigerant tubing to the refrigerant coils.

Compressor enclosure panels shall be heavy-gaugeand crossbroken for additional rigidity to dampenvibration. Complete interior of compressorcompartment shall be lined with amulti-functional material that serves as a soundbarrier, an absorber of sound and a decoupler tothe compressor enclosure. This multi-functionalmaterial shall have a mylar coating on the face toact as a sound reflector and to increase the strengthof the material. Damping material shall betextured foam type.

The exterior of the compressor compartment shallbe coated with a high density damping materialto minimize impact noise and vibration. The rightend panel, right-hand front panel, 3 feet (914mm)of the right-hand end of the center front paneland the hinged top access door shall be coated witha high density material to eliminate noise and vibration.

VentiMatic shutter (room exhaust) —Where indicated, the unit ventilator manufacturershall provide an “in-room” air relief VentiMaticshutter mounted on a separate wall intake louverto prevent excessive static pressure build-up In theroom. The VentiMatic shutter shall be constructedof galvanized steel with shutter dampers of wovenglass fabric impregnated with silicone rubber.

Temperature controls — The unit ventilatormanufacturer shall provide factory installed,calibrated, and tested temperature controls. Unitsthat are capable of providing up to 100% outsideair shall provide a microprocessor-based DDCcontrol that can monitor conditions and automati-cally adjust unit operations to maintain theserequirements. The control sequence shall be onthe basis of [ASHRAE II]. This DDC controllershall have the following tenant adjustments: (1)room temperature setpoint, (2) minimum percentoutdoor air setting, and (3) unoccupied setpoint(offset). An LED status/fault indicator shall befurnished for inspection and a communicationsport shall be incorporated to allow manipulationby a remote PC. The remote PC shall be able toaccess and change pertinent operating aindroom conditions from a remote location. Themicroprocessor-based control must be capable ofcommunicating to a local IBM-compatible PCusing the RS-232 protocol. When using thisremote PC, the unit must be capable of reactingto changes made by the remote PC. The remote

PC must also be able to access all pertinentoperating and room conditions.



Wall-mounted sensor — Units shall have atemperature sensor with status LED furnished formounting to the wall. [Option: In addition, atenant override switch shall be furnished as partof the wall mounted sensor.)

Wall-mounted sensor with tenant over-ride and setpoint adjustment — A sensorwith integral tenant override and status LEDshall be furnished with the unit ventilators.This sensor shall also contain a manuallyadjustable temperature setting allowing thecontroller setpoint to be increased or decreasedby 3°F (2°C).

Wall sensor with setpoint adjustment —Units shall have a sensor furnished with a manu-ally adjustable temperature setting allowing thecontroller setpoint to be increased or decreasedby 3°F (2°C).

[Accessory] Ventilation lockout relay —Units that are not on network control shall be fur-nished with a [24V] [120V] ventilation lockoutrelay to permit closing the outdoor damper dur-ing normal occupied operation. Outdoor airdamper shall close when the relay is energized bya [24V] [120V] signal.

[Accessory] Exhaust fan interlock relay— Each unit shall be furnished with an exhaustfan interlock relay. When energized by a [24V][120V] external signal, the outdoor air dampershall move to the 100% outdoor air position andshall remain fully open.

[Accessory] Night control with unit day/night switch (stand-alone units only) —Each unit (except slaves) shall be furnished with aunit mounted day/night switch to permit manual


indexing from day to “night” mode.The unoccu-pied offset temperature setpoint(s) shall be in forcewhen indexed to the “night” mode. The outdoorair damper shall remain closed at all times duringthe “night” mode.

[Accessory] Night control with unit day/night relay — Each unit (except slaves) shallhave a factory installed relay for day/nightchangeover. This relay shall have a [24V] [115V]holding coil that, when energized by an externalsource, shall be automatically indexed to thenight mode, placing the unoccupied temperaturesetpoints in force. The outdoor air dampershall remain closed at all times during the“night” mode.

[Accessory] Night control withunit-mounted time clock — Each unit shallbe furnished with a unit-mounted, field pro-grammed time clock for day/night changeover.This clock shall have a battery backup that willprovide up to 150 hours of operation during apower outage. A unit-mounted holiday switchshall be furnished to allow manual changeover tounoccupied control for extended or otherwiseunscheduled periods.

Wall sleeve — The galvanized steel, one-piecewall sleeve shall be set in a wall opening and buttedup directly against the intake louver.


It shall be the installing contractor’s responsibilityto make the final load side power wiring connec-tions between the wall sleeve junction box and theunit terminal block (including the wiring goingto the electric heating elements.)(The wall sleeveshall be cartoned separately and shipped to thejobsite preceding the unit ventilator. Junction boxshall ship separately for field installations.)

Wall intake louver — The wall intake louvershall be supplied by the unit manufacturer andshall be of heavy-gauge [unpainted] [painted][clear anodized] aluminum construction. Thelouver shall be of the [horizontal] [vertical] bladetype with weep holes along the face of the bottomedge of the louver frame. A 1⁄2" (13mm) squaremesh bird screen shall be provided on the back ofthe wall intake louver. [Option: A four-side flange

Models ARQ, ERQ

Specifications Water Source Heat Pump Units (Continued)

shall be provided around the perimeter of the louverwhere required.] Lintels shall be provided by thecontractor above the wall intake louver opening.

(Optional: Heavy-duty lattice grille horizontal andvertical lines shall “line up” with the louver bladesto present an aesthetic appearance. Grille shallbe fabricated from mill finish aluminum. The standardaluminum allow shall be [unpainted] [painted][clear anodized].)

©1999 AAF-HermanNelson

The information in this catalog supersedes and replaces previous [catalogs][bulletins] with regards to AAF-HermanNelson Incorporated Terminal AirConditioning products. Illustrations cover the general appearance of AAF-HermanNelson products at the time of publication. AAF-HermanNelson reserves the right to makechanges in design and construction at any time without notice.

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4900 Technology Park Boulevard Auburn, New York 13021-9030 USA (315) 253-2771

Catalog UV-1-231F / / (6/99)

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