The Northwest Energy Efficiency Alliance (NEEA) recently announced the winner of the $10,000 grand prize in its "Discover Ductless" campaign. The campaign encouraged homeowners to upgrade their inefficient electric heating with ductless heating and cooling systems. These systems heat and cool at a fraction of the cost of electric baseboard and wall heaters, typically saving homeowners 25 to 50 percent on heating bills.
Ductless heating and cooling systems are reversible, 2-way heat pumps that use electricity to transfer heat between outdoor and indoor air by compressing and expanding refrigerant. Using a refrigerant vapor compression cycle, like a common household refrigerator, ductless systems collect heat from outside the house and deliver it inside on the heating cycle, and vice versa on the cooling cycle.
Ductless systems use variable speed compressors with “inverter technology” (AC to DC) in order to continuously match the heating/cooling load, avoiding the on/off cycling of conventional electric resistance and central heating systems that is commonly associated with uncomfortable temperature variations and high energy consumption.
As the name suggests, ductless systems do not require the use of air ducts. Ductless systems consist of an outdoor compressor unit and one or more indoor air-handling units, called “heads”, linked by a dedicated refrigerant line. Indoor heads are typically mounted high on a wall or ceiling covering a 3” hole where the refrigerant line passes through from the outside unit, which is mounted at the base of the house. Each indoor head corresponds with a heating and cooling zone that can be controlled independently.
Starting in 2008, the Northwest region's utilities have taken a leadership role in championing ductless heating and cooling technology. In the last 3 years more than 13,000 ductless heating and cooling systems have been installed in the Northwest, at a savings of 40,500,000 kWh hours per year. That's enough electricity to power 3,805 average homes for an entire year.
Ninety-two utility partners in Idaho, Montana, Oregon and Washington offer customer rebates on energy-efficient ductless systems – up to $1,500 or up to 40 percent of the cost of an installed ductless heating and cooling system. Ductless heating and cooling systems have the potential to save the Northwest region 200 aMW of energy savings each year—the equivalent to powering more than 150,000 homes each year.
John J.P. Howley
Woodbridge, New Jersey