Five Percent: Conserve Energy

Last week, it was colder outside than the temperature inside my fridge and freezer … but the fridge kept running — why can’t it use the cold air from outside? And while I am asking questions, why do I need a humidifier in winter while exhausting that nice, hot, humid air from our showers outside with a fan? Or, that nice hot humid air from the dryer — big plumes of hot air into the icy cold? It smells nice, too.

Our homes and their appliances are dumb as stumps. Or, is it us?

To be sure, the bathroom exhaust fan is not a simple problem — there are indeed times when that which is being exhausted is, um, best left outside.

But the clothes dryer — if you put in a dryer sheet, you’re sending nice smelling, warm, humid air outside (and, by blowing air outside through one hole, it is replaced by sucking in cold, dry, outside air through some other leak or hole). The fridge is even more perverse: 20°F outside, and the motor is running? Huh?

Afraid To Be Too Smart

Of course the reason for these inefficiencies is simply that adding smarts to appliances increases complexity, and that increases cost.

Making my dryer do the right thing would require a humidity and temperature sensor, a relay, and a servo motor plus some additional ducting, and most likely some other smarts that make sure mold isn’t building up. A heat-exchanger on the vent pipe might be a start.

The fancy fridge that uses cold air only makes sense north of New Jersey, probably. And yes, you have to duct the cold air in from somewhere. But hey, that same duct could probably be used to push hot air (from the motor running) outside when it’s warm.

Why cannot these appliances be smart?

It probably costs too much.

Heat Exchange

Efficient houses that are tight and insulated need to draw in air from outside in order to maintain air quality. These houses use heat exchangers, which are fundamentally simple devices. If it’s cold outside, they pull heat from the warmed indoor air being exhausted and use it to warm up the fresh air being pulled in.

If it’s warm outside, they pull the coolness (lack of heat, technically) out of the air being sent outside to cool off (un-heat) the air being drawn in. I ain’t rocket science — fins like the ones on radiators are used to transfer heat. Fans blow one way or the other, although that’s even optional.

Am I being overly simplistic?

Costs More Than I Have

Part of the answer lies in total efficiency. Forgetting (for a moment) the materials cost of creating the additionally complex systems needed to manage this heat exchange, or the effort and energy needed to install the equipment, the question may simply be: how much energy that we’re using from electricity (or gas) to do one thing is being done for free by mother nature … and that we can get at without too much trouble. But: the costs of adding one sort or other of heat exchanger to any heating or cooling device is likely to be more than a few dollars.

How much more is irrelevant for most consumers: more cost (now) is: worse.

In a competitive world, where cash now is valued above all else (irrationally so, say the behavioral economists) … and in a world where we cannot put an accurate price on energy (such that the energy from coal has lower cost than energy from sun or wind or nuclear) … no consumer is going to pay the extra $100 to $300 it might cost for such a contraption. Even if it saves them the extra cost in a year or two.

Internal Rate of Return

This equation, known as internal rate of return, or IRR by business people, is the basis for most business investments. If there’s no risk (as in this case), an IRR that exceeds the expected cost of money over time, or interest rate, is a good investment. It wouldn’t matter whether it took 1 year or 10 years to break even, it’s still a good investment.

Yet, IRR appears to be almost completely irrelevant for regular people. Like me. In this case the calculus is usually a trade-off between a given expenditure and what I can afford now. So if I have $800 to spend, and need a new fridge and can get one that is big enough for $700, I have $100 to spend on something else. Even if the extra $100 spent would result in savings of $100/year. Normal people don’t calculate IRR. They calculate how much is left.

(It was my great epiphany, 20 or so years after graduating from college with an Economics degree, that most people don’t even begin to follow the basic assumptions that underly traditional economic theory. Back then, I spent my paycheck, and (hopefully) not a penny more. Or less. And after another 5 years, I realized the same was true with most companies. And after 25 years, I don’t think most people are that different, even if they may have the luxury of spending a little more.)

Common Sense Isn’t Common

It’s obvious to anyone with common sense that blowing hot air out of a house in winter is dumb. Are we really willing to accept “dumb” just because the economics don’t quite work out?

Answer: yes, we are willing to accept dumb until the economics work out. So: let’s make the economics work out. The sooner we do, the easier it will be.

Photo credit: striatic via Flickr