While I was talking to my sister the other night, she mentioned this device, shown to the right mounted on a hot water heater. It's an
AirTap Heat Pump, designed to heat a household's hot water using the same technology that cools the innards of a refrigerator.
This thing has one immediate benefit; its exhaust is cold. One could duct that exhaust to chill, say, a keg cooler or beverage reefer . . . for free.
Actually, for years I've wondered why someone didn't combine hot water generation and refrigeration, taking advantage of the facts that:
Water feeding most water heaters is usually colder than ambient air, improving coil chilling efficiency;
Water conducts heat more efficiently than air; and
Hot water is generally used extensively in rooms with refrigerators. I can see one wrinkle in this little plan: Since one must run cold supply water lines and hot water feed lines, one would pretty much be stuck placing a reefer in only one spot. Still, what's the difference between that hard-plumbed scenario and reefers that need a water line for ice makers? I've been wanting to test the feasibility of a combo reefer/water heater for years, but haven't had the the necessaries; expendable cash, tools, installation skills, kitchen space, Wifely willingness to experiment . . . et cetera ad infinitum ad naseum.
Ducting the output from this little unit to an insulated box, though. . . . That I could do.