Heat Water With A Window AC?
I'm still thinking about heating water with 1/3 the usual energy using a Haier 5K Btu/h window AC ($84 at Wal-Mart.) The pipes connect to the condenser coil at the top, so we could build a thin aquarium around it with no replumbing or recharging and pump 1.5 gpm of 110 F water out through a $168 Doucette SB1-20 400 Btu/h-F plate heat exchanger with a 110 F thermostat and pump 60 F cold water into the other side of the heat exchanger from a cold kitchen tap and back into the hot tap, and dump some hot water from the hot tap into the sink with a solenoid valve if the cold tap ever reaches say, 100 F, when/if the tank water heater completely fills. Heating 50 gallons of 60 F water to 110 takes about 21K Btu, and the AC would make about 5000(1+1/3) = 6700 Btu/h, so we might fill the tank in 3 hours, with no hot water use. When I blocked the Haier AC condenser airflow to make the exit temp 110 F, its cool air temp and power use (from a Kill-a-Watt) barely changed. This could be more efficient than a typical "portable air conditioner" with air hoses. Removing the condenser fan blade might also raise the COP.
Answer:
I like your thinking, it should work. I take it your not really thinking about hooking hoses up to the spouts of the kitchen sink taps, but to the pipes feeding them. About 40 years a go one of my friends had a water cooled central air system in his Massachusetts home. All the equipment was in the basement furnace room. The cooling water went down the drain most of the time, but he did have a valving setup which allowed him to water his lawn with that warm water if he wanted to. Googling "heat pump water heater" got over 49,000 hits, and it looks like it's proven technology: I haven't followed it, but the thing is, you have to understand the concept - it's very basic. Instead of the high-side ( hot compressor discharge gas ) going to a coil with air blowing over it, it goes to a heat exchanger with water on the other side. That's all there is to it. I recall Amana used to do it, I forget who else. It will be efficient in the same way a heat pump is - moving heat instead of converting some other form of energy into heat. But the plumbing had better not be set up like Nick said, cause it just don't work. And it had better have some kind of relief to control head pressure, for instance a secondary air coil with appropriate valving and thermostatic control. And it better be on a SERIOUS compressor, not the little throw-away rotary things they put in throw-away window-shakers. 'Serious' meaning 'real', like Copeland, Tecumseh, Bristol, etc.