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Electric Radiant Ceiling Heat
The most maintenance-free house heating system is electric radiant heat cables embedded in the ceiling plaster. That statement will no doubt start an argument anywhere, but are things considered, it’s hard to disagree with. There’s no furnace whatsoever to maintain, no ducts to find a place for, no chimney or flue to clean, no baseboard radiators to get in the way of furniture or to look ugly, no gas leaks to worry about, no blower noise, no oil truck to wait frantically for, no wood to chop and carry or ashes to take Out. Radiant ceiling cables also produce the cleanest heat. Time spent dusting and repainting ceilings is halved.
So what are the drawbacks? Once in awhile you have to replace a thermostat. On very rare occasions, a break develops in the network of cable that needs to be repaired. Electricians familiar with ceiling cable systems have ways to pinpoint such gaps exactly and repair them by removing only a very small amount of plaster. But in this regard, you run into the main drawback. Not many electricians want to mess with the intricate web of cable in a ceiling. Installing it requires an attention to detail that is almost craftsmanlike. We are fortunate to have an electrician who is in my opinion a genius. He can fix gaps in ceiling cable, but as he likes to point out, almost all the repairs he makes are in ceilings someone else installed. Lesson 1: If you can’t find electricians enthusiastic about radiant heat ceiling cables, better choose some other system.
As is the case so often, the best low-maintenance systems are among the costlier ones. Installing ceiling cables costs as much or more as a gas or oil furnace, and it requires a plaster ceiling or plaster on drywall. The cost, however, is not so great when you compare it to the ductwork required for hot air furnaces or baseboard radiators or water-heating systems. But since electricity is not a very efficient way to heat, so common wisdom says, you pay more for it than for oil or gas. Even in this respect, radiant ceiling heat is not as expensive as an electric resistance furnace, and there’s a good argument, all things considered, that its expense is reasonable.
It amazes me when experts say that gas and oil are more energy- saving than electricity for heating a house when they don’t count the enormous amount of energy used to manufacture and distribute gas and oil furnaces, ducting, fuel tanks, etc. Nor do they count the enormous amount of energy spent in carting oil around in trucks and boats and pipelines. They talk about how efficient the new gas furnaces are, which is true, but some of that efficiency is gained by using electric ignition rather than pilot lights, and in the new condensing furnaces (see “Gas and Oil Furnaces,” below), there is an electric inductor motor and perhaps other electric accessories that help circulate air and combustion gases to attain that efficiency. And remember, blowers on gas and oil furnaces are run by electricity. All things considered, I have a hunch radiant heating cables might be much closer to gas and oil in total energy use than we are led to believe.
Radiant ceiling heat is weird stuff. It doesn’t really heat the air the way a warm air furnace does, but rather heats objects in the air. Thus, if you have your feet under the table they may feel a bit chilly (one of the minor drawbacks of this kind of heating) while your head is comfortably warm. By not heating or moving the air radiant heat saves energy. And you feel warmer than when a hot air furnace or heat pump circulates warm air around the room. Moreover, radiant heat is a very even heat since it is the same all over the room—no cold corners that a furnace must work twice as hard to warm before the thermostat turns it off. And best of all, you can adjust the heat in every room as needed or turn it off completely in rooms not occupied. Carefully used (and of course that is the key to everything), this kind of heat in our experience is not so terribly expensive in spring and fall, when temperatures are between 300 and 60°F, if the house is very well insulated, as it must be for electric heat. In really cold weather, the meter can spin merrily away, but how much this really costs in comparison to gas or oil heat in really cold weather I can’t say from experience because we heat with wood in December, January, and February.
But a friend here in cold northern Ohio heats entirely with radiant electric ceiling heat and he swears by it. His electric rate is 6.2 per kilowatt-hour, and last year he paid out $672 for electric heat for a house of 2,700 square feet. Considering the convenience and the lack of any maintenance, can you beat that? One reason (I think) for his economy is that the house is a split-level, like ours, and the bottom floor nestles into a hill on three sides. Ground temperatures of about 55°F keep that level from ever getting real cold, and so it is easier to keep warm. My friend discounts this because his house, at least on the top level, is not very well insulated, he says, since it was built before the energy crisis. He believes this type of heat is just not that wasteful of energy, and that electric heat gets its bad name from electric resistant furnaces and baseboard heaters. “And a lot of people tend to throw their heating bill into one lump with their air-conditioning bill. We don’t have air-conditioning,” he says.
Nevertheless, electric radiant ceiling heat is not a popular choice. Where people warn electric heat, they are choosing, the heat pump more arid more, because it cuts electric usage to nearly half of electric resistance heaters or ceiling cable. Also heat pumps are air conditioners, too, and save the price of buying a separate unit for that. Indeed, heat pumps are better air coolers than they are space heaters. Improvements may alter the following advice, but as of now, air-source heat pumps are really economical only where winters are mild. When the temperature drops below about 15°F they kick into a conventional electric resistant mode of heating and that will kick up your utility bill real fast.
Some new units, called dual-fuel heat pumps, are made to work in tandem with another fuel, so that in cold weather the heat pump turns off and a gas or oil heater comes on instead of using an electric resistance heater. Their purchase is questionable because if you have to have a gas or oil heater anyway, the heat pump can be justified only as an air conditioner.
Our electrician believes the all-around “best” heating system, as a compromise between low maintenance and cost, is a water-source heat pump. Instead of drawing heat out of cold winter air, it draws it out of groundwater, which maintains a temperature of about 50° to 55°F. The most economical water-source heat pump can be enjoyed only by those who have a well. Systems that circulate water and antifreeze through pipes buried in the ground are more costly to install.
The very latest experiment in energy-saving electric heat is called electric thermo-storage, and my electrical genius acquaintance has in stalled a few such systems. The savings come from the discount you can get from many utility companies by using the bulk of your electric energy during off-peak periods. Some electric utilities are encouraging electric thermo-storage for this reason; if they can keep electric usage down during peak periods, it means lots of money saved overall. Ohio Power right now offers an off-peak rate of only 3 cents per kilowatt-hour to encourage developments like electric thermo-storage. (In our area, water heaters have a control on them that the utility company can turn on or off at central headquarters. If peak load starts going too high, they shut off our water heaters and turn them back on in the wee hours of the morning when not much electricity is being used. So far we have never lacked hot water, nor have I heard anyone else complain, while the utility company has been able to save enormous amounts of money, which hopefully they are passing on.)
In electric thermo-storage, a massive heat storage sink is built in the ground under the house. The material might be stone, brick, or another storage mass—experimenting is still underway. This mass is heated with off-peak electricity, enough to keep the house warm until the next off-peak period. Homeowners claim an 80 percent decrease in heating costs over conventional electric heat. This is something to ask about, especially if you are building new, although the system can be integrated into an existing house. However, where winters are cold you’ll need a supplementary source of heat: electric thermo-storage will raise the temperature on cold days only to the mid-60s at best.
Such a system is obviously low maintenance—mostly electronic monitors and fans for air circulation. With a heat pump there is consider ably more to maintain. Generally there’s a unit installed in your house and another outside. The compressor and one heat exchange coil are outside, and a blower and another heat exchange coil are inside. Freon refrigerant moves the heat back and forth between outdoors and indoors, in one direction in summer and another in winter by means of a clever reversing valve.
Gas and Oil Furnaces
The cheapest way to heat if you have to buy fuel, is with gas—or oil when it is as inexpensive as it is right now in late 1986. Improvements, especially the new condensing furnaces as they are called, in both gas and oil heaters have increased their efficiency remarkably. Condensing furnaces have two heat exchangers in them capable of wringing almost all the heat out of escaping combustion gases. Gas condensing furnaces have efficiency ratings of 90 to 95 percent, while those fueled by oil have ratings of 85 to 90 percent, which justifies their higher price over conventional furnaces (they sell for about $2,000). Another great advantage is that gases are cooled so low that a real chimney is not needed. Oil needs a galvanized pipe; gas only a plastic one. But in shopping, pay particular attention to how the condensation is handled. By the time circulating air scrubs the last heat from combustion gases, they have cooled to where condensation occurs. This condensate can cause corrosion on the heat exchanger. Check to see how the warranty covers that.
There are many good condensing furnaces on the market and by the time you read this every dealer should have one to sell. If not, Amana, Whirlpool, and Lennox (see Appendix A for addresses) are good brands with which to start your investigation. Lennox is also a front-runner in the much ballyhooed pulse combustion furnaces. These are even more expensive (around $3,000) but use gas so conservatively by employing intermit tent combustion rather than a steady flow of gas that payback may well justify the price. But pulse combustion requires more intricate electrical devices, and as my electrician says: “They are wonderful as long as everything is working, but there’s a lot that can go wrong.”
Maintenance on gas and oil furnaces is about the same: clean the blower at least once a year, clean or replace the filter, clean the flue, and make sure the fuel nozzles aren’t partially plugged. On water-heating systems, you also need to bleed air out of the radiators about once a year. Oil furnaces get dirtier quicker than gas ones and are more complicated to service. Many fuel companies or furnace dealers have a regular service program well worth the cost. But if you want to do the work yourself, it’s much easier to watch carefully and ask lots of questions as a serviceman does the work than try to understand printed language about heat ex changers, electrodes, transformers, cartridge gaskets, etc.
A good indication that your oil furnace needs cleaning is lots of soot in the flue inside the damper on the flue. You can check easily by lifting the damper door and peeking inside. A gremlin often overlooked is a plugged filter in the supply pipe from the oil tank to the furnace. The filter is sort of a little cup in the line, usually right outside the tank.
Other overlooked potential troublemakers are the pump and blower motors. The motors on older furnaces need a few drops of oil twice a year or more in their little oil cups with the snap-down lids. If you ignore that detail long enough, the motor will freeze up. The main filter above the blower is easy enough to replace or wash if it is the washable kind. The fans on the blower itself need cleaning less often, but if you shirk this job, you will pay for it in higher fuel bills and shorter motor life. Since the blower is a beast to get to in most oil furnaces, I think the annual servicing by a professional is well worth the cost.
Gas furnaces are somewhat easier to clean, but the whole job is one I think you should watch a serviceman do at least once. In order to get to the blower fins the blower usually needs to be removed from the furnace. Although that is not particularly complicated and well within the capability of anyone mechanically inclined, I still suggest getting a briefing from your serviceman and/or studying closely the maintenance manual that comes with your particular furnace.
A usual maintenance repair job on gas furnaces is replacing the thermocouple device that automatically turns off the gas if the pilot light goes out. Of course, with the newer electronic controls, pilot lights are obsolete and so are thermocouples.
If the blower is belt-driven, replace the belt when it begins to fray or show serious wear. Or at least have a new belt ready. Otherwise, the old belt will break on a Saturday night when the temperature is below zero and your serviceman is out of town.
Adjusting air ports on the burners is simple if you know what you are doing, but again, I suggest having your furnace dealer or serviceman do it. Money spent for real technical expertise is seldom wasted. At any rate, if you do decide to do it yourself, be sure to heed your manual and turn off all necessary switches and valves beforehand.
Combination furnaces—usually wood or coal combined with gas or oil—increase your security, and, if you have your own wood, may decrease your fuel bill. But there’s no maintenance advantage—in fact, more things can go wrong on a combination furnace than on a regular one.
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