The Quick Green Blog - An Appraiser View

Air quality, often the most-cited important feature of Green Built Certified Homes, is achieved through capturing, controlling, and diluting the source through filtration.

Healthy indoor air quality is important for energy efficiency and comfort, and is accomplished with a tight building envelope. Air filtration through walls, for example, contributes to energy loss and is also a source of mold when warmer conditioned air condenses as it reaches a cooler surface in the wall cavity.

A tight building shell does create the need for an intentional means of introducing fresh air into the living space. Introducing air into the home in a controlled manner has both an energy and IEQ advantage.

The first step involves calculating the building's heating and cooling BTU load requirements.  Then the type and size of HVAC equipment is determined to meet that load.  Finally, the supply and return ductwork is laid out and sized for the structure.

When installing gas furnaces or fireplaces use direct-vent equipment and/or install induced mechanical draft in a combustion closet to minimize the quantity of combustion-generated pollutants entering the home and the unnecessary loss of indoor air to support these devices.

Tip: Look for Energy Star certified HVAC units with high SEER, HSPF, and AFUE ratings to minimize utility expenses and reduce consumption of natural resources involved in energy generation.

INDOOR AIR QUALITY VERIFICATION BY THIRD PARTY INSPECTIONS

Inspectors verify:

• Duct installation and sealing
• Building envelope air sealing details (i.e. sealing utility transits in wall plates)
• Proper insulation installation: Cut accuracy, cavity fill, gaps, voids, or compression
• Sealed crawl and attic ventilation
• Windows and doors are flashed, caulked, and sealed properly
• Direct vent equipment and perform door pressure
• Proper balance of exhaust and supply fans and energy recovery ventilators