United States. The Celebration Green Design & Build Waystone Farm project is competing in Energize Connecticut's 2016 Zero Energy Challenge.
With nearly two-thirds of a home's energy consumption coming from heating, air conditioning and water heating, a home's mechanical systems are just as important as a home's wrapping. This is particularly true when designing and building the Passive House standard.
For Waystone Farm, celebration green design team & Build considered several key elements when planning and selecting the house's HVAC systems, including connecticut weather, a root cellar in the basement, and the need for mechanical systems to act in unison with other key passive house design principles.
The team chose the Water Furnace Series 7 geothermal heat pump system to meet heating and cooling needs, a Zehnder Energy Recovery Fan (ERV) for ventilation, and an 80-gallon Stiebel Eltron 300E heat pump for the home's domestic hot water system. Combined with the airtight envelope and other passive house building principles, these systems will save homeowners between 70% and 90% of annual energy costs.
The geothermal heat pump provides heating and cooling for the Waystone farm using the consistent ground temperature of the earth and converting it into usable energy through a closed loop system. In turn, decreasing the amount of energy needed to heat and cool the home.
The ERV system recovers heat and moisture from the air stream as it passes through the core of the unit, reducing a home's heating and cooling load and contributing to the overall energy performance of the home. ERV systems also ensure excellent indoor air quality by diluting contaminants and reducing humidity. This is a result of how the system circulates air; Fresh filtered air enters the home in areas such as bedrooms and upper living spaces with rancid air removed from areas such as bathrooms, kitchens, and laundries.