November 8, 2010

            Dear Ken:   My furnace and water heater sit in a 1000 SF unfinished basement.  There are two cold air vents to the outside to bring in air.  Can I block them off?   Ellie

            Probably.  The rules about combustion and make-up air have changed over the years.  After the OPEC oil boycott in the early 70's, energy saving came to the forefront, and homeowners began  to seal up their houses in response.   Buildings suddenly became more airtight, so combustion air-what you use to burn the natural gas in the furnace and water heater-became less available.  That's when we introduced those fresh air vents you complain about to make up for that lost air.  We now realize that houses-in spite of our obsession with energy saving-leak enough air to allow us to capture that needed volume mostly from the inside.

            Trouble is, the new rules are quite arcane.  Usually you can install a half-louvered door to the furnace room and maybe a grille here and there.  That allows those obnoxious holes to the outside to be permanently covered over.   Don't do this yourself, however--let your HVAC company OK any new arrangement for that fresh air.  Why?  If you make a mistake, you can let fumes into the house.

            Dear Ken:   What do you think of pellet stoves?  We live in the eastern plains and would like supplemental heat.    Janet 

            I like them.  They are quiet, unobtrusive and pretty much odorless.  In fact, I'm seeing them more and more in city houses-especially in the lower levels where it's always chillier than the rest of the house.  Cost-wise, the initial capital expense is daunting;  they can run to $3000 or more installed.  But the operating expenses are fairly easy to swallow.  I've seen studies that show wood pellets can be cheaper then the propane you're probably using now.  Shop around   assiduously.  This is a pretty competitive business, so you should be able to get some nice, low estimates for your new stove.  You could also buy one in a box and install it yourself, but remember, you'll need to pull a building permit-and the installation-particularly from a safety standpoint--can be quite tricky.

            Dear Ken:   Our smoke detectors go off in the middle of the night.  I've changed batteries and blown them out, but it still happens.  Any ideas?  Bob

            If you blew them out with too much air pressure, you may have somehow partially blocked up the sensors.  First, though, try switching them around from one opening to another to see if they quit alarming.   If you can isolate the  naughty one, then replacing it should solve your problem.

            According to the Kidde company, smoke detectors have a limited life anyway.  Their sensors and circuitry get less sensitive with time, so they should be replaced at  least every ten years or so.  The same with carbon monoxide detectors, although their useful lives are shorter-about seven years.

            Smoke and carbon monoxide detectors are pretty cheap when compared to their life-saving benefits, so if you have any doubts about one or more, just recycle and replace them.  

            Dear Ken:   I heard your discussion about tankless water heaters.  I'm not a huge fan of them either, and I wanted to point out that regular water heaters heat the basement a little.      Harry

            You're right:  the steel tank radiates its heat into the living space.  The problem is that water-because of its thermal mass-is harder to heat than air.  That's why I recommend a "blanket" around the tank.  You can buy an insulation kit at the hardware store for less than $15.  Of course, this especially applies to electric water heaters-because of their high operating costs.