Now stretch it actually arduous and rapidly maintain it to your higher lip, which is delicate to temperature. You will really feel that it is hotter than it was earlier than. That’s since you’re including vitality to the rubber band, which will increase its temperature.

Are you prepared for the superior half? Keep it stretched for a short while till it returns to room temperature. Now let the rubber band loosen up and rapidly contact it to your lip once more. It’s now colder than room temperature! Seriously, do that for your self.

So if you happen to had a sufficiently big rubber band, may you employ this to chill your home? Wait a minute, you are gonna say: In the primary stage, after we stretched the rubber band, it bought sizzling, after which it cooled again to its unique temperature—and in doing that it heated the air. You’re proper. But what if we may vent that hotter air exterior? Then you possibly can hold simply the cooling section inside.

Boom. You simply re-invented the air conditioner! Instead of a rubber band, an AC has a fluid known as a refrigerant that circulates in a closed loop from inside to exterior. This fluid has a low particular warmth, so it adjustments temperature rapidly, and a really low boiling level—turning right into a fuel at one thing like –15 Fahrenheit.

How’s it work? The fuel is first compressed, inflicting it to warmth as much as like 150 levels. The sizzling fuel circulates in a set of copper coils exterior, with a fan blowing over them, so the fuel loses thermal vitality to the ambiance. (Copper additionally has a low particular warmth.)

Then it is pumped again inside, the place the strain is rapidly diminished, inflicting it to increase and immediately cool right down to round 40 levels. As the now chilly fluid circulates by indoor coils, a fan blows heat inside air over it, heating the fluid once more and cooling the indoor air within the course of. As the system circulates, it principally picks up thermal vitality indoors and carries it outside.

By the best way, that is precisely the identical course of that your fridge makes use of to maintain your cheese and soda chilly. In each circumstances, the method makes one thing inside cooler and one thing exterior hotter. Put your hand behind the fridge and you will see what I imply. Just for kicks, this is a man who really built a refrigerator that runs on rubber bands.

So Heat Pumps Aren’t New!

You thought this was going to be an article about warmth pumps, proper? Well guess what. We’ve been speaking about warmth pumps this complete time, as a result of they run on the identical ideas. A warmth pump cools your property similar to an air conditioner, by circulating a refrigerant and ranging the strain to alter its temperature, so it takes thermal vitality from one place and places it in a unique place.

So again to the massive thriller: How can a warmth pump enhance the temperature of indoor air on a chilly day with out really producing any warmth? Simple: Just run it in reverse! This time we let the new compressed refrigerant cool off inside the home to lift the indoor air temperature. The low-pressure, chilly fuel then goes exterior to heat up.

Warm up exterior? Yep. Even on a freezing day, the air nonetheless has thermal vitality. So lengthy because it’s above absolute zero—which, consider me, it’s, since that is round –460 Fahrenheit—the air molecules are in movement. And since we’re cooling the refrigerant to, say, –15 levels, which is decrease than winter temperatures in most locations, it can wring thermal vitality out of even frigid air.

Of course, you possibly can’t get vitality without spending a dime. Heat pumps depend on electrical energy to drive the compressor and followers. But you probably have photo voltaic panels at house, or if the electrical energy in your space is even partly from non-carbon sources, replacing a gas furnace with a heat pump can make a big difference in lowering greenhouse fuel emissions. And it’s going to in all probability decrease your utility payments within the course of.