Pretty much every domicile I can think of has some leaks that were put there on purpose. Sometimes these can work against you. The Death Star,for instance, met its end when Luke Skywalker dropped a bomb down an exhaust vent. Tsk. Silly Death Star designers!

It's unlikely that someone will plop a proton torpedo down your dryer vent at home, but ... hey, you never know.There are a lot of wackos out there, and it is every American's duty to be paranoid about unlikely events. Even if terrorists are not eyeing your suburban island in the sun you might want to go pat your clothes dryer on its hardworking little head.

Not that you are saying a precautionary goodbye to your little R2D2 (Rotating 2-speed Dryer model 2), but so that you can check its temperature. Fever is unlikely, but chills are another story, and are "catching". The rest of your home can catch cold from your dryer.

If your dryer is cold to the touch (and the weather is cold outside), you might be losing a lot of heat through a stuck or clogged dryer vent. Dryers vent their damp air through a flapper valve -- so called because it flaps open under air pressure from the dryer, and flaps closed otherwise under the usually reliable influence of gravity and perhaps a spring or small magnet. You can see it, or reach inside and feel it, from the outside. It looks and feels flappy. I mean, it's a flap, for cryin' out loud.

If you reach inside and feel nothing flappy, there is a good chance the flap is still there, but is encrusted in the open position with lint. In any event, if you can stick your fingers into the wall from the outside, you have a problem. If the flapper is stuck open, just pull the lint out with your fingers until it frees up. When it's clean, it should flap down to the closed position. Not only will this keep cold air from sneaking into your house, but it will keep mice from making nests in your nice, warm dryer. (Yes, they do.)

While you're there, make sure the vent opens all the way, too. A flap that doesn't open means your dryer is going to take a heck of a long time to dry your clothes, and waste a lot of energy in doing so.

And since you are outside, snaking your fingers into external orifices (of your home), ponder for a moment if your kitchen stove has a vent fan that might vent to the outside. (Some fans simply recirculate air into the kitchen through a filter -- until the filter fills up with grease and catches fire. This is probably not the safest or most efficient way to clean the filter.) 

Go around to your kitchen wall and see if there is a vent there. Same deal with a flappy thing, only this might be stuck open with grease, ewwww. Or, perhaps the mice have propped it open with a stick or acorn. If you find they have built a tiny deck and barbecue area, it may have been open for a while. It undoubtedly fails to meet code, so turn them in to your local building inspector. It's one thing to have mice, and quite another to have greaser mice. Oh, yes, and you are probably losing heat there, too, if it's stuck open.

Bathroom fans also have -- you guessed it -- flappers. Which explains why the mice have opened a night club and are selling bootleg bathtub gin ... out of your bathtub.  Even if the ratatat of tiny mobster machine guns is not keeping you awake nights, you can bet that this establishment is packing heat. Right out your wall.

Some of the most promising technologies in the thrust towards more efficient heating and cooling are advances in heat pumps. A great example of this is Hallowell's Acadia heat pump, designed to extract heat from the air of even a northern winter. Historically, "air-to-air" heat pumps don't offer quite the heating "efficiency" of ground-sourced, geothermal heat pumps because they have to extract heat from air that is far colder than the earth temperature. That said, they are easier and cheaper to install, requiring about the same installation as central air conditioning. Plus, in a July 2009 article by Lauren Hunter at Remodeling magazine, Hallowell claims their air-to-air system can be even more energy efficient than geothermal in cold weather performance. That seems to me to violate laws of thermodynamics, but the universe may have written escape clauses in these laws since I went to school.

The trouble is, Hallowell is not competing with geothermal systems on a level playing field at the moment -- simply due to oversight.

In the necessary haste to keep a teetering world economy from imploding, it appears that the drafters of the energy portion of the US economic stimulus legislation relied on existing industry standards for high-efficiency heat pumps. That's not unreasonable, but unfortunately these standards covered only high-efficiency two-stage heat pumps, leaving out the possibility of more stages. The Acadia is a three-stage heat pump, and works even better than two-stage pumps -- but the tests required to qualify for the unlimited 30% tax credit have to treat it as a two-stage machine! Not surprisingly, it didn't qualify, as it was never designed to run that way. (It does qualify for an EPA Energy Star rating.)

It's as if gas-mileage standards had been written for four-speed transmissions. Fifth gear (or "overdrive" as it used to be known) makes many of today's small-engine cars efficient. If they had to be tested using only the first four gears, they wouldn't measure up.

This omission is, apparently, in the course of being rectified by waivers, but in the meantime Hallowell is losing sales it should have won. It is a very attractive system according to an owner whose home I visited. So don't write it off -- check it out, check out the latest in the tax credit / waiver situation with Hallowell, and see if it might be the system you need.