Dear Jim: You recently mentioned “super” gas furnaces. I want low utility bills and reliability, but comfort is most important. I am willing to spend extra to get the best available. What’s new and best in 1998? — Ed D.
Dear Ed: You are in luck! The new designs of “super” efficient condensing gas furnaces also provide the best comfort. In order to utilize the most efficient “super” central air conditioners, you will need the special blower system that comes with these furnaces.
You will notice improved comfort from less temperature swings, less indoor drafts and better humidity control. You can expect to cut your heating bills by 30 percent and your summer cooling bills by slightly less.
All super furnaces use condensing heat exchangers. Not to bore you with technical details, but by condensing water vapor in the gases, less heat is lost out the flue (as little as 5 percent). Many of these designs have lifetime warranties.
With a super furnace, your chimney is no longer used. The flue gases are so cool (almost all the heat stays in your house) that they are vented outdoors through an inexpensive 2-inch-diameter plastic pipe.
For the greatest savings, choose a furnace with sealed combustion. The combustion air is brought into the furnace by another small low-cost plastic pipe. This also reduces chilly drafts indoors.
Sealed (isolated from indoors) combustion minimizes the chance of carbon monoxide poisoning, not uncommon with older gas furnaces. A small blower in a sealed furnace forces the flue gases outdoors.
If you are willing to spend a little more for the very best, select a two-stage burner design with a variable-speed blower. With the two heat levels, it automatically adjusts to the changing heating needs of your home.
These variable-speed blower models provide the best central air-conditioning comfort and efficiency in the summer too.
Consider installing a combo “thermidistat” with a variable-speed blower. You set both the humidity and temperature level. If your house is warm enough, but too dry, just the blower starts (no heat) to humidify the air. In the summer, if it is too humid, the blower runs slower to hyper-dehumidify.
Write for or instant download (www.dulley.com) Update Bulletin No. 741. Please include $3 and a business-size SAE.
James Dulley, Bangor Daily News, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.