2011 expo low-ebuildings_ventilation_jm_0911
DESCRIPTION
Low Energy Buildings and Ventilation A presentation by Jason Morosko of Ultimate Air, Athens Ohio Presented at the Columbus Green Building Forum's 2011 Green Building EXPOTRANSCRIPT
Low Energy BuildingsAnd Ventilation
Jason Morosko www.UltimateAir.com Athens, [email protected]
About Me:
Jason Morosko, MSME, Certified Passive House Consultant
Manufacturer/Designer of energy recovery ventilation equipment
High performance home design consultant, specialty in envelop/mechanicals
Currently building a passive house – Oct 2011Currently building a passive house – Oct 2011
“The concern is right on—that a tight house without enough fresh air is a bad thing. But the g f gsolution—to keep the house leaky—is wrong”
“What is more important than the air you breathe?”breathe?”
TOPICS
Design overview – low energy buildingsImpact of ventilation – importance of ERV’sERV design – and what’s on the marketERV design – and what s on the market
DISCUSSION
What makes a house – energy efficient? How can we measure it?A house should be designed before it is built (including the mechanicals).)A note on a set of plans I was reviewing – “HVAC, plumbing, and electrical are to be design build. “ This should not happen.
TERMS – what do they mean?EER, SEER, COP, Ton of cooling, BTU, kWh, HSPF, AFUE
Th ffi i i f h ti i t ?The efficiencies of heating equipment….?
Consider – the heat loss of ducting/piping/installation can be up to 35% Duct in the conditioned space?35%... Duct in the conditioned space?
Orientation can have more than a 20% impact on conditioning
Net Zero?
IS ORIENTATION IMPORTANT?
ENERGY EFFICIENT
• Definition of “green”, “low energy”, “net zero”, “LEED”, “passive house”…. • Air infiltration, IAQ, cfm50… and how are they relatedAir infiltration, IAQ, cfm50… and how are they related• Energy recovery ventilation• How does a house lose heat (or gain heat)• The ‘awesome’ house
I l d• Insulated• Air sealed• Best windows and doors• Least envelop penetrationsp p• Best layout for efficient construction• Orientation (windows)• Shading• thermal bridge free• thermal bridge free• design and build for long life
BRAINSTORM
Thermal Envelop? How does heat move into and out of the building?Conduction Convection and RadiationConduction, Convection, and Radiation.R‐Value? Walls? Windows?
VENTILATION
‐ Exhaust only‐ Supply only
Balanced: Air flow into and out of a defined volume in equal amounts
‐ BALANCED
Balanced: Air flow into and out of a defined volume in equal amounts
Mechanical: Not passive? Usually with an electrical fan motor
Ventilation: Controlled movement of air into and outVentilation: Controlled movement of air into and out of a building, generally using mechanical means, through deliberately placed holes in the Building Envelope ‐John Bower
Heat Recovery: The transfer of heat energy between air streams
Energy Recovery: The transfer of heat and latent (moisture) heat energy between air streamsair streams
Types of Ventilators
Cross Flow and Counter Flow Flat Plate Cores
How Does A Rotary ERV Work?
As Stale Indoor Air is Exhausted
Heat and moisture are captured in core materialbefore stale air
C d
before stale air is exhausted
Captured heat and moisture are transferred to fresh air stream -Ai i fi
F h Fil d C di i d Ai i D li d
Air is filtered
Fresh, Filtered, Conditioned Air is Delivered
ERV vs. HRV
l bIn most applications it is better have moisture transfer
1. Hot humid outside condition: remove humidity from the incoming air = ERV2. Cold outside – dry inside: return as much humidity as possible to the inside = ERVhumidity as possible to the inside ERV3. Cold outside – excessively humid inside:
exhaust some humidity, but not all = ERV
If l t t ll h idit fIf you always want to move all humidity from the outside to the inside, or from the inside to outside, or if the humidity inside and outside are always favorable = HRVy
Choosing a ventilation unit
1. Energy Efficiency Rating2 Moisture Transfer Rating2. Moisture Transfer Rating3. Cost‐of‐Ownership4. Ease of Installation/Operation4. Ease of Installation/Operation5. Fan power6. Filtration7. Service
( )
Indoor Air Quality
How do we improve Indoor Air Quality (IAQ)?
First: Source Control‐no pets, harmful cleaners, voc loaded building materials, …..
Second: VentilationSecond: Ventilation‐bring air in from outside, expel air from inside, as efficiently as possible
Third: FiltrationThird: Filtration‐clean the inside air
Contaminants
OutdoorPollensMoldsMoldsDustRADON
IndoorPeopleP t d d VOC’Pet dander VOC’sFormaldehydes CO2MoldsB t iBacteria
Current Recommendations
0.35 ACH Universal3,000 ft2 x 8 ft ceiling = 24,000 ft3
24 000 f 3 0 35 ACH 8 400 fh24,000 ft3 x 0.35 ACH = 8,400 cfh8,400 cfh / 60 = 140 cfm
ASHRAE 62.2 Minimum Ventilation For LowRise Residential
# bedrooms + 1 x 7.5 cfm = 37.50.01 cfm x 3,000 ft2 = 30 cfm
Total = 67 5 cfmTotal = 67.5 cfm
Room Type/Classification Total Ventilation Capacity
CSA‐F326 Residential Ventilation Requirements 150 cfm
Room Type/Classification Total Ventilation CapacityA Rooms cubic feet/minute (cfm)Master Bedroom (1) 20 Basement (unfinished) 20 Si l B d (3) 10Single Bedroom (3) 10Living Room (1) 10Dining Room (1) 10Family Room (1) 10y ( )Recreation Room (1) 10Other Habitable Rooms 10
B RoomsB RoomsKitchen (1) 10Bathrooms (2) 10Laundry (1) 10Utility Room 10
PHPP and ventilation rates
PHPP ill l l t i til ti fl dPHPP will calculate maximum ventilation flow, and average 24/7 operational flow
Looking both at achieving 0.3 ACH per volumeAnd looking at occupation driven requirements
Ventilation System Details
DEFINITIONS
EER and SEER Energy Efficiency Ratio and Seasonal EER…… Window AC use EER. Central AC use SEER. BTU capacity divided by the wattage. In the case of SEER – the ratio is defined by a particular season (climate).y p ( )BTU/watt‐hour.Simplicity: Ave COP = 0.293 * SEER
COP Coefficient of performance. Unit less. Heat output divided by l t i l i t BTU H / BTU Helectrical energy input. BTU per Hr / BTU per Hr.
HSPF Heating season performance factor. A measure of overall heating efficiency of a heat pump. ‘Average’ seasonal COP. Ave COP = 0.293 * HSPF
AFUE Annual fuel utilization efficiency. The average thermal efficiency of the equipment for a year.
TON 1 refrigeration ton = 12,000 BTU/hr. Heat (removed) required to melt 1 ton of ice (2000lbs ) in 24 hours1 ton of ice (2000lbs.) in 24 hours.
TYPICAL AFUE VALUES
Fuel Furnace/boiler AFUE
Heating oilCast iron (pre‐1970) 60%Retention head burner 70‐78%gMid efficiency 83‐89%
Electric heatingCentral or baseboard 100%Geothermal heat pump see COP
Less tha
Air‐source heat pump see HSPF
Natural gasConventional 55‐65%Mid‐efficiency 78‐84%
an 1 COP
Condensing 90‐97%
PropaneConventional 55‐65%Mid‐efficiency 79‐85%
P!
Condensing 88‐95%
FirewoodConventional 45‐55%Advanced 55‐65%S f h A 75 90%State‐of‐the‐Art 75‐90%
Source: http://en.wikipedia.org/wiki/Annual_fuel_utilization_efficiency
THERMAL BRIDGE DISCUSSION
Definition of a thermal bridge: A building element which has a linear thermal transmittance of greater than 0.01 W/mK – according to passive house.g / g p
= 0.005778 BTU/hr.ft.F OR – R value less than 14.42.