2016 ASHRAE Winter Conference

Residential energy codes have rapidly advanced, and many builders offer “Net Zero Energy” or "Zero Energy Ready" homes.  But as homes get more efficient, risks of design and installation defects increase.  Increased insulation can elevate moisture risk inside wall assemblies. Increased air tightness can lead to IAQ problems without proper ventilation.  Lower envelope loads reduces HVAC system air flow and can lead to poor comfort control. Energy efficient homes must also be high performance homes. This presentation will describe innovative solutions for high performance homes and retrofits under U.S. DOE’s Building America program that minimize risks and maximize comfort.

The energy-efficiency levels of new homes built in the U.S. has improved significantly in the past decade with developments in building science and improved construction practices according to the United States Department of Energy (DOE). The improvement in the building thermal envelope and several other factors can cause the house to operate intermittently at a negative pressure.  Natural gas appliances can vent properly at a negative pressure, but some appliances only operate within limits.  This presentation explores the operating limits and provides data on performance from recent laboratory testing of appliances under depressurized conditions.

Part of the energy performance increase in new homes and homes being retrofitted is due to reducing the air leakage through the building envelope. However, a high performance home should still have good indoor air quality and therefore requires ventilation to remove pollutants from individual sources, such as in kitchens and bathrooms, generated by occupants and their activities and from building materials and furnishings. This seminar will discuss how to apply ASHRAE 62.2 in high performance homes and show how to improve upon the basics required in the standard through selection of different ventilation approaches and equipment.