The HVAC system in this home has many features, multiple energy sources, back-up systems, and redundancies. These features help to make it energy efficient, very functional, air quality conscientious, and adaptive to the unique needs of homes of this magnitude in this area.  Using a combination of solar thermal energy, hydronic flooring, coupled with a forced air system, geothermal energy for both heating and cooling, along with sophisticated, prioritized, staged controls, this HVAC system is capable of efficiently producing a highly controllable and comfortable interior environment.

ERV’s

Our home employs two ERV (energy recovery ventilators) to help lower energy consumption. By taking air that is to be exhausted from the home and passing it through the ERV’s, the latent heat is exchanged to the incoming airstream. The air coming into the home gets conditioned to be closer to the current interior temperature, resulting in less energy use to heat or cool it, depending on the season. The RenewAire units used have the added benefit of using water vapor transfer during the heat/cool exchange process that adds to the overall efficiency. Additionally they help modulate interior humidity levels. This system is tied to the bathroom exhaust fans, which are triggered by motion sensors that are timed to make the appropriate number air exchanges for the space.

Radiant Floor Heat

Uponor radiant floor heating systems circulate warm water through cross linked polyethylene (PEX-a) tubing embedded under the floor for the most superior comfort with the greatest energy efficiency and indoor air quality available. Radiant works with all types of flooring and is beneficial for people with indoor allergies. Radiant floor heating is cleaner, more efficient, consistent, less drafty, quieter and more comfortable than traditional forced air heating systems. The home is additionally equipped with a forced air system that is primarily for AC, and while the forced air system is also capable of producing heat, the radiant floor system is the primary heat source for the home. The zoning of this system also helps to make for more efficient heating. Uponor’s PEX-a plumbing systems provide the fastest, easiest, installations with the highest durability and the greatest reliability in residential and commercial plumbing applications. It also offers the traditional PEX benefits such as corrosion resistance and heat retention. The Uponor Climate C_ntrol™ Network System was employed to control the heating and cooling for the home and  is an integrated hardware and software package that connects all of a structure’s heating, ventilation and air conditioning (HVAC) components to a single system for better energy efficiency.

MERV 13 Air Filters

As per LEED for Homes specifications, we opted to use MERV 13 air filters in the forced air portion of HVAC system. This earned us extra LEED credits, but also works in conjunction with the rest of the HVAC system to provide superior interior air quality.

Local Exhaust

In bathrooms not tied to the ERV’s, Energy Star Rated local exhaust fans were used. Panasonic Whisper Quiet fans were chosen for their unbelievably quiet operation, their energy efficiency, and their overall quality. These will be installed with timer switches to eliminate excess exhaust of conditioned air, while simultaneously allowing for the appropriate number of air exchanges.