Downside to high-efficiency furnace?
Reliability rumor examined
October 30, 2009
By Paul Bianchina
Inman News®
Q: Is a high-efficiency furnace more likely to break down compared to a mid- or low-efficiency one?
A: High-efficiency furnaces, those with a rating of 82 percent to more than 96 percent efficiency, are designed to extract and utilize some of the waste heat that would otherwise be exhausted out through the flue.
Accomplishing this task requires additional fans, valves and electronic controls within the furnace, and with more moving parts you have more things that can go wrong and therefore additional potential for breakdowns. However, I'm not aware of any substantial reliability issues that would cause me to shy away from purchasing a high-efficiency unit.
I would get at least two bids from licensed, experienced HVAC contractors, and have each contractor bid both a mid- and a high-efficiency furnace that is correctly sized to your home. Look at the cost difference between the two efficiencies, and ask each contractor to calculate how long it will take for the energy savings from the more expensive high-efficiency unit to pay back its higher cost. You may find that the investment doesn't make financial sense for you.
You also want to ask each contractor for reliability data for the brands of furnaces they carry, and also look at what the warranty is on the heat exchanger. The heat exchanger is the most expensive part of the furnace, and a long warranty -- say 20 years or more -- is often also a good indicator of how reliable the manufacturer feels the furnace is in general.
Q: We have a two-story house that is about 12 years old that has had squeaky floors for nearly the whole time we've owned it. We are considering selling and would like to correct this problem before we start go to market. It seems that the two general contractors that we have talked to didn't sound confident they could correct the problem. I am sure the carpeting would have to come up. Do you have any suggestions?
A: Floor squeaks, as you might imagine, are caused by two pieces of wood rubbing against each other, or by the wood rubbing against a fastener. The noise can actually come from a number of different sources, but since you mention that your house is fairly new and has carpeted floors, I'll stick with that scenario.
First of all, you need to do a little more research. Walk around on the floor, locate as many of the squeaks as possible, and mark them on the floor with pieces of masking tape.
If the squeaks are all occurring near walls, it is probably due to lumber shrinkage around the nails that hold the wall to the floor. This can usually be fixed by simply driving wooden shims between the top of the subfloor and the underside of the wall plate, which can be done without disturbing the floor covering or the trim.
If the squeaks are not near walls, they are probably coming from movement between the subfloor and the floor joists below, which could come from inadequate nailing or insufficient or improperly applied adhesive.
If the floor of the house was framed with solid lumber as opposed to I-joists, the noise can also be coming from wood that has dried out and twisted or pulled away from the wood or supports adjacent to it, causing movement -- and noise -- between the two pieces.
For these squeaks, one of you will need to go under the house with a strong light and tape measure while the other one stays up top. Using measurements and pressure on the floor from walking, try to locate from underneath where the squeaks are coming from, and what -- if anything -- is going on in those areas.
You may see the floor joists deflecting up and down; you may see them rubbing against other wood, or against ducts or pipes; or you may see that some of the supports under the joists are not fully touching one another.
In the event of gaps between pieces of wood, you may be able to solve the problem by taking wooden shims, coating them with woodworker's glue, and driving them into the gaps with a hammer. If the wood is moving against a pipe or duct, you can correct that through the use of additional strapping to stop the movement.
If you find a lot of areas where the subfloor seems to be moving up and down on the joists -- as opposed to them moving up and down together -- then the answer is probably going to be to drive screws down through the subfloor (from above) and into the joists. The best way to do this is to roll back the carpet and pad to access the subfloor underneath.
There are also some products on the market that allow you to drive the screws down through the carpet itself and then snap them off below the carpet, but these are only effective if you have one or two squeaks in a confined area. Be aware also that driving anything down through the carpet may void the carpet manufacturer's warranty.
Remodeling and repair questions? E-mail Paul at paulbianchina@inman.com.
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