Low Energy Buildings And VentilationJason Morosko www.UltimateAir.com Athens, Ohiojmorosko@ultimateair.com
About Me:Jason Morosko, MSME, Certified Passive House ConsultantManufacturer/Designer of energy recovery ventilation equipment High performance home design consultant, specialty in envelop/mechanicalsCurrently 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?”
TOPICSDesign overview – low energy buildingsImpact of ventilation – importance of ERV’sERV design – and what s on the marketERV design – and what’s on the market
DISCUSSIONWhat 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, AFUEThe efficiencies of heating equipment….?Th ffi i i f h ti i t ?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 conditioningNet Zero?
ENERGY EFFICIENT• Definition of “green”, “low energy”, “net zero”, “LEED”, “passive house”…. • Air infiltration, IAQ, cfm50… and how are they related Air 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 penetrations pp • Best layout for efficient construction • Orientation (windows) • Shading • thermal bridge free thermal bridge free • design and build for long life
BRAINSTORMThermal Envelop? How does heat move into and out of the building?Conduction, Convection, and Radiation.Conduction Convection and RadiationR‐Value? Walls? Windows?
VENTILATION ‐ Exhaust only ‐ Supply only ‐ BALANCEDBalanced: Air flow into and out of a defined volume in equal Air flow into and out of a defined volume in equal amountsMechanical: Not passive? Usually with an electrical fan motorVentilation: Controlled movement of air into and out Controlled movement of air into and out of a building, generally using mechanical means, through deliberately placed holes in the Building Envelope ‐John BowerHeat Recovery: The transfer of heat energy between air streamsEnergy Recovery: The transfer of heat and latent (moisture) heat energy between air streams air streams
How Does A Rotary ERV Work?As Stale Indoor Air is Exhausted Heat and moisture are captured in core materialbefore stale air before stale airis exhaustedCapturedC dheat and moistureare transferred tofresh air stream -Air i fiAi is filtered Fresh, Filtered, Conditioned Air is Delivered F h Fil d C di i d Ai i D li d
ERV vs. HRV In most applications it is better l b have moisture transfer1. 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 = ERVIf you always want to move all humidity from If l tt ll h idit f the outside to the inside, or from the inside to outside, or if the humidity inside y and outside are always favorable = HRV
Choosing a ventilation unit1. Energy Efficiency Rating2.2 Moisture Transfer Rating Moisture Transfer Rating3. Cost‐of‐Ownership4. Ease of Installation/Operation Ease of Installation/Operation5. Fan power6. Filtration7. Service
Indoor Air QualityHow do we improve Indoor Air Quality (IAQ)? ( )First: Source Control ‐no pets, harmful cleaners, voc loaded building materials, ….. Second: Ventilation ‐bring air in from outside, expel air from inside, as efficiently as possibleThird: Filtration ‐clean the inside air
ContaminantsOutdoor Pollens Molds Dust RADONIndoor People Pet dander P td d VOC’s VOC’ Formaldehydes CO2 Molds Bacteria B t i
Current Recommendations0.35 ACH Universal3,000 ft2 x 8 ft ceiling = 24,000 ft324,000 ft3 0.35 ACH = 8,400 cfh24 000 f 3 x 0 35 ACH 8 400 fh8,400 cfh / 60 = 140 cfmASHRAE 62.2 Minimum Ventilation For Low Rise Residential# bedrooms + 1 x 7.5 cfm = 37.50.01 cfm x 3,000 ft2 = 30 cfm Total = Total = 67.5 cfm 67 5 cfm
CSA‐F326 Residential Ventilation Requirements 150 cfm Room Type/Classification Room Type/Classification Total Ventilation Capacity Total Ventilation Capacity A Rooms cubic feet/minute (cfm) Master Bedroom (1) 20 Basement (unfinished) 20 Single Bedroom (3) Si l B d (3) 10 Living Room (1) 10 Dining Room (1) 10 Family Room (1) y ( ) 10 Recreation Room (1) 10 Other Habitable Rooms 10 B Rooms B Rooms Kitchen (1) 10 Bathrooms (2) 10 Laundry (1) 10 Utility Room 10
PHPP and ventilation ratesPHPP will calculate maximum ventilation flow, and PHPP ill l l t i til ti fl d average 24/7 operational flow Looking both at achieving 0.3 ACH per volume And looking at occupation driven requirements
DEFINITIONSEER 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 * SEERCOP Coefficient of performance. Unit less. Heat output divided by electrical energy input. BTU per Hr / BTU per Hr. l ti l i t BTU H / BTU HHSPF Heating season performance factor. A measure of overall heating efficiency of a heat pump. ‘Average’ seasonal COP. Ave COP = 0.293 * HSPFAFUE 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 hours. 1 ton of ice (2000lbs ) in 24 hours
TYPICAL AFUE VALUES Fuel Furnace/boiler AFUE Cast iron (pre‐1970) 60% g Heating oil Retention head burner 70‐78% Less tha Mid efficiency 83‐89% Central or baseboard 100%Electric heating Geothermal heat pump see COP an 1 COP Air‐source heat pump see HSPF Conventional 55‐65% Natural gas Mid‐efficiency 78‐84% P! Condensing 90‐97% Conventional 55‐65% Propane Mid‐efficiency 79‐85% Condensing 88‐95% Conventional 45‐55% Firewood Advanced 55‐65% State‐of‐the‐Art S f h A 75‐90% 75 90% Source: http://en.wikipedia.org/wiki/Annual_fuel_utilization_efficiency
THERMAL BRIDGE DISCUSSIONDefinition 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.