This piece was originally published in the July 2017 issue of electroindustry.
Greg Galluccio, Vice President, Engineering and Product Management, Maxlite; Dixie Comeau, President, Dixie Comeau Consulting Inc.
Last March, we introduced electroindustry readers to our net-zero home in Warwick, New York. We are framed, closed, and thrilled.
Designing an efficient heating, ventilation, and air conditioning system was a major accomplishment.
The area of the house is about 2,000 square feet on the main floor and another 1,000 square feet (partially underground) on the floor below. Although the house is not large by most standards, the HVAC design is challenged by vaulted ceilings that peak at 24 feet. Despite construction and insulation methods that nearly hermetically seal the interior, the space requires a cocktail of three different heating and cooling technologies to maintain comfort through the hot summers and cold winters of New York State.
After analyzing the space and consulting with our contractor and HVAC experts, we created a unique system to condition our home efficiently.
The vaulted great room, consisting of kitchen, dining room, living room, and music room, will be served by a combination of radiant heat in the floor and a pair of electric mini-splits located on the walls, about 12 feet high, at the rear-facing wall. The bedrooms, bathrooms, den, and utility areas will be heated and cooled by a gas-fired hydronic forced air system, delivered by an insulated ductwork layout.
Electrical components will be tied to the solar energy supply, while a buried propane tank will deliver fuel to cooktop burners and fireplace. An instantaneous (tankless) water heater will feed showers and baths.
To properly control humidity and temperature, three heating/cooling platforms will connect to a single automated control system that will respond to wireless sensors located in key areas throughout the house. With some software tweaking, we expect the systems to keep the indoor humidity within a prescribed range while maintaining comfortable temperature levels.
Since the house is essentially airtight, a low-volume air-handling and air-circulating system will keep fresh air flowing at all times. All air-handling ductwork and water carrying pipes were routed through conditioned space inside the house (as opposed to exterior walls), so the amount of heat loss across the ducting and piping systems is negligible.
Although we are getting maximum efficiency with a low carbon footprint in a state-of-the-art home, it is rather expensive. We’re happy to be first adopters for much of the technology, and believe that as these methods of construction, insulation, and climate regulation become more commonplace, the returns on investment will improve dramatically.
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