Getting more heat from the heat pump


February 23, 1997|By Karol V. Menzie and Randy Johnson

EVERY NOW AND then, some topic seems to grab readers' attention. A couple of years ago it was roofs; this time around it's heat pumps.

A reader in Columbia wrote to ask whether to take advantage of a chance to connect to existing gas lines and trade in his heat pump for a gas furnace. His heat pump is relatively new, but the air-handling system is two decades old.

Most people who want to trade in the heat pump feel that it doesn't deliver warm-enough air. Although the air coming out of the ducts is 85 degrees, it's colder than body or skin temperature, so it can feel cold. The system compensates for cold by using electric-resistance heat at intervals. Fossil-fuel burning systems -- gas or oil -- can produce hotter air, so you feel more comfortable. But many people have already addressed the cold-air issue by using fireplaces or wood stoves to supplement the heat pump.

If the house is comfortable, or the rooms where the family generally congregates are warm enough, you might want to stick with the heat pump. Newer ones are said to work better, and (see the next letter) there are things you can do to increase your comfort level.

One problem with switching to a fossil-fuel system is that houses designed for heat pumps may lack chimneys. However, the newer systems can be installed anywhere you can get a flue to the outside wall. Gas furnaces can be vented through plastic pipe to the outside. They also use an air supply system to bring in outside air for combustion, rather than interior air. Oil furnaces need a metal flue, but are also easily installed. Prices are comparable for new systems -- the fossil types might be $400 to $500 more expensive.

Help from Eastern Shore

If you're unhappy with the temperature of the air blowing out of your heat pump's ducts, a device made by an Eastern Shore company might increase your comfort level.

It's called the Comfort Guardian, and it's essentially a computer that evens out the heat pump's use of electric-resistance heat. Instead of providing a burst of extra-hot air to even out the air temperature, the Comfort Guardian senses temperature dips, and doles out electric-resistance heat as needed to maintain a temperature of about 96 degrees -- air that will feel warm on your skin.

The device doesn't raise or lower energy use by itself, but David Stevens and James Mowery, co-founders of the company, say it may result in energy savings anyway, partly through ending "thermostat jiggling" by those who think they're freezing. And, as long as you feel warm, you may be able to turn the thermostat down as much as 3 or 4 degrees. According to the Baltimore Gas and Electric Co., for every degree you can turn the thermostat down, you will save 3 percent on your utility bill.

Richard Hobson, BGE director of new product and technology development, said the utility is investigating the Comfort Guardian to see if it wants to recommend the device, and others like it, to customers. If the device works as promoted, he said, "It could be an answer to the problem of cold air from a heat pump."

Hobson said there are other things homeowners can do to help make heat-pump heat more comfortable. "Balancing the air-distribution system, so air gets distributed evenly around the house, will help," he said. "Putting a humidifier on the furnace will help too," because more humid air will feel warmer and cause less drying of skin (and furniture). Also, using a programmable thermostat made for heat pumps can help adjust the energy load to times when it is most needed and reducing it when it is not, such as at night and during the workday.

If you want to try the Comfort Guardian, heating contractors charge about $350 to $400 to install it on the indoor unit of the heat pump. The job takes about an hour. "It's just a simple add-on," Mowery said, so there's no disruption. For more information, or to find a contractor in your area, call (800) 229-2615.

Cold floors

A Baltimore reader has another problem with cold air -- a cold floor in a family room over a crawl space. She wanted to know if the floor joists could be boxed in to keep the cold air away. The simple answer is no, you can't box in the joists -- but there are still some things you can do to warm up cold floors. If the floor of the crawl space is bare dirt, it should be covered with a layer of heavy plastic and that covered with several inches of gravel. The spaces between the joists should be insulated with fiberglass batts, as thick as will fit, at least R-19. Indoors, rugs can help feet stay warm -- and wall-to-wall carpeting provides the best insulation.

Pub Date: 2/23/97

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