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Watch for false energy claims

With winter just around the corner, you need to brace yourself for more than just cold blasts of arctic air.
HW_electric_heater_claims
Beware of efficiency claims applied to electric heaters. With rising energy costs

With winter just around the corner, you need to brace yourself for more than just cold blasts of arctic air.

You also need to prepare for plenty of technical malarky masquerading as energy conservation science.

Beware.

Snake-oil charlatans are vibrant and vigorous in the 21st century, and they’ve been given a new lease on life with our increasing interest in energy conservation.

Here’s how a little knowledge of physics can protect you from sneaky sales pitches that promise energy savings that can never actually happen.

The cost of heating your home depends on three things and three things only: how much heat escapes from your house, how much you pay for the energy entering your home, and what portion of the energy you buy actually translates into warm air.

And of these three factors, the last one — generically called “efficiency” — is used most often to fool people. And a classic example of this funny business arrived in my shop for testing last fall. It was a new kind of electric heater that came with tall promises.

Product packaging claimed this new device saves more than 70 per cent compared with conventional heaters, and strictly speaking, this fact is true — or at least half true.

Yes, the new heater does consume substantially less power — 400 watts compared with 1,500 watts for standard heaters. But it also puts out correspondingly less heat.

In fact, every single penny of electricity it does not consume is exactly proportional to the warm air it does not deliver. It’s like claiming that a new kind of bread has half the calories per slice, with a slice that’s half as big as normal. Where’s the gain in that?

We’re so used to technical products becoming more efficient that we believe the possibility for efficiency gains exist everywhere.

They don’t, and electric heaters are one example. They’re already 100 per cent efficient. Every last kilowatt hour of electricity you pay for is converted into heat by every single electric heater on the planet. Old or new, it doesn’t matter.

Claims to the contrary are widespread and often based on bizarre technical fiction that sounds legitimate on the surface.

In the case of the miracle 400-watt heater, the manufacturer claimed that because it was wall-mounted, with a small space behind to allow air circulation upwards, the unit made you feel as warm as all the other 1,500 watt electric heaters on the planet. Really? That’s quite a claim. I only wish it were as easy to circumvent the immutable laws of physics as it is to mount a heater an inch away from a wall. It simply makes no difference.

The only heating systems that do deliver more apparent warmth for a given unit of energy consumed is radiant in-floor heating designs, and that’s not because of some hocus-pocus techno magic. A warm floor simply makes your whole body feel somewhat warmer at a slightly lower room temperature. That’s it.

So, what can you really do to lower your heating costs this winter?

It comes back to the three fundamentals behind the issue: the amount of heat leaving your house, the cost of energy entering your house, and the conversion efficiency of energy input to heat in the building.

If you’re got particularly leaky windows, then new ones will help a lot. Also, in almost all cases, the easiest, most cost-effective way to reduce heating costs is by blowing more loose-fill insulation into the attic. And after work is done up there, do whatever it takes to seal that attic hatch against air leakage.

Lots of warm air often gets lost through loose-fitting hatches. Not very glamorous stuff, I know, but when you’re tearing open your utility bill this coming February, glamour really isn’t what you’re looking for, is it?

Steve Maxwell is Canada’s award-winning home improvement expert, and technical editor of Canadian Home Workshop magazine. Sign up for his free homeowner newsletter at www.stevemaxwell.ca