Showing results 1 - 30 of 30
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A central fan-integrated supply system uses a fresh air intake ducted to the home's central furnace or air handler unit to supply fresh air throughout the home
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A direct-vent sealed-combustion fireplace takes its combustion air directly from outside through a dedicated air inlet and vents combustion products directly outside
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A direct-vent sealed-combustion furnace has dedicated pipes for combustion air and exhaust
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A powered flow hood is used to measure outside air flowing into the inlet terminal of a whole-house ventilation system
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An energy recovery ventilator draws in fresh outside air that is filtered and circulated by the central air handler, while stale air from central returns is routed through the ERV to exchange heat before being exhausted outside.
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Because flue temperatures are cool, intake and exhaust ducts on a Category 4 direct-vent sealed-combustion condensing furnace can be made of PVC
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For fireplaces that are not mechanically drafted or direct-vented to outdoors, total net rated exhaust flow of the two largest exhaust fans is .15 CFM per 100 sq. ft. of occupiable space when at full capacity
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Furnaces, boilers, and water heaters located within the home’s pressure boundary are mechanically drafted or direct-vented
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If integrating an ERV/HRV with the heating/cooling duct system, add dedicated ducts for either the supply or return side to prevent short-circuiting of air distribution
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Indoor measurement of a whole house mechanical ventilation system with a pressure balancing flowhood provides a sheltered location for measuring airflow
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Lower-cost local ERVs are usually installed in a ceiling to supply outdoor air to and exhaust air from the room in which they are located
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National Fuel Gas Code (NFPA 2012) identifies four categories for combustion furnaces and water heaters based on combustion type (sealed or unsealed) and vent pipe temperature
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Right – The corridor in this multistory building is pressurized with outdoor supply air.
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Right – The elevator lobby of this multistory building is pressurized with outdoor air supplied to the space through this ceiling supply register.
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Right – The HVAC unit installed in the insulated attic uses a heat pump to provide heating and cooling while also providing dehumidification and fresh air ventilation.
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Right – This energy recovery ventilator provides fresh air and exhausts stale air through a heat exchanger that recovers heat from the outgoing air in winter and reduces heat from incoming air in the summer to provide ventilation without wasting energy.
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The natural draft and induced draft furnace are both Category I appliances that receive combustion air from the combustion appliance zone
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The raised hood at the base of the vent stack on this water heater shows that it is an atmospheric vented gas water heater
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The ultra-efficient ground source heat pump (COP 4.4) delivers conditioned air throughout the home via ducts; an ERV provides fresh air to the system.
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These ERV/HRV configurations are NOT recommended because outdoor air can be sucked back into the ERV/HRV before being distributed to the living space
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This HRV, installed in a conditioned attic, provides balanced ventilation to the whole home
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