Sterling Hydronic Unit Heaters

Steam and Hot WaterHorizontal and Vertical

Horizontal Unit– Standard (Header Type)

Available in steam or hot water

Casing constructed out of 20 gauge die-formed steel

Standard with adjustable horizontal louvers

Totally enclosed fan motor standard

(19) Sizes 18-360 MBH Coil connections on top

and bottom of unit ETLc Certified

Horizontal Standard Coils

Cast bronze saddles braised to copper header

Copper tubing Aluminum fins Factory tested at 200 PSI Max working pressure

150 PSI Max steam temperature

366 ⁰F Pipe connections have

internal threads for ease of connection

Horizontal Unit - Serpentine• Hot water only• Casing constructed out of 20

gauge die-formed steel• Standard with adjustable

horizontal louvers• Totally enclosed fan motor

standard• (4) Sizes 8-36 MBH.• Coil connections on side of

unit• OSHA fan guard is standard• ETLc Certified

Horizontal Serpentine Coils

• Coil is serpentine design with 3/8” copper tubing. Tubing connections shall be 3/8” copper tubing, type “M”

• Aluminum fins• Factory tested at 200

PSI• Max working pressure

150 PSI• Pipe connections have

internal threads for ease of connection

Vertical Louvers (Horizontal Units)

Vertical louvers are available as a field installed accessory

Allows for the adjustment of airflow for 4-way air control

Vertical – Standard Available in steam or

hot water Casing formed by two

square steel plates Totally enclosed fan

motor standard (15) Sizes 41-705 MBH Coil connections on top

and bottom of unit ETLc Certified

Vertical Unit Coil

Copper coil with aluminum fins mechanically bonded to the tubes

Coils are tested at 375 PSI

Max working steam pressure of 75 PSI or hot water up to 225 PSI or 325 ⁰F

Threaded steel pipe coil connections

Vertical – Low Output

Field knock-outs (15) Sizes 34-620

MBH Reduced

temperature rise

Louvers (Vertical)

OSHA Fan Guards

• Louver Cone Diffuser

Motors

Explosion Proof Totally Enclosed

Steam Pressure and Water Control

Steam Pressure Control

Strap on Hot Water Control

Starter and Speed Control Switch

Manual Starter

5.0 Amp Speed Control Switch

Phenolic Coating V1 – Phenolic Coating (Air Dried)

◦ The unit is coated with the Heresite VR-514 coating. ◦ It is a special primer-finish combination that is

specifically designed for salt water services.◦ It is ideal for use in building located on or near the

ocean or other large bodies of salt water.

V2 – Phenolic Coating (Baked)◦ The unit is coated with the Libcote-7-9818 coating.◦ It is specifically designed for use in moist, wet or damp

environments. ◦ It is ideal for use in waste water treatment plants or in

spaces with excessive amounts of steam or humidity in the air.

HS Tstats U1- Line

Voltage Stat “Off/Auto Switch”

U2 – Line Voltage Stat “Auto/Off/Fan Switch”

U3 – Line Voltage Stat “Auto/Off/ Fan Switch”

Tstats Continued U4 – Celsius Line

Voltage Thermostat (Fahrenheit version

shown)

W1 – T6169C Line Voltage Thermostat w/Subbase (Light Duty) – (VS Only)

VS Tstats W2 – T4051A

Line Voltage Thermostat (Heavy Duty)

W4 – Q651A1009 Stat Subbase Only (Used with T4051A1003 for “Off/Auto Switch”)

Disconnect

115/230 Single Phase

• 208/230 Three Phase

• 460/575 Three Phase

HS Room Layout

When selecting unit size and location keep the following items in mind: How close will the unit be to

people and small items? You don’t want a unit 4 feet from someone’s desk blowing 5,500 CFM at them

Always direct units toward areas of higher heat loss such as bay doors and truck loading docks

Fans with higher RPM will be louder than fans with lower RPM

See unit IOM for additional information