All Forum Posts by: Tanya F.

I started my refrigeration system hacking back in 1991 when I lived in a college dorm suite during the summer in Illinois.  The midwest gets very hot during the summer, and this dorm had no air conditioning which made sleeping at night miserable.  The college banned window air conditioners, so that was not an option.  We had free water in the bathroom of our dorm, and I am pretty handy.  I took an old window A/C that I bought for $25 and I cut the stock air cooled condenser out of it.  I then used a piece of PVC pipe and some copper tubing to make a water cooled refrigeration condenser which we connected to the A/C unit to replace the air cooled condenser.  I used an old solenoid valve from a junk humidifier to turn on the water when the A/C compressor started.  We tapped the water line under the sink to get our cooling water for the condenser, and then we ran a hose into the toilet where we dumped the hot exhaust water down the drain.  It was kind of noisy and butt ugly, but it worked really well !

We had the only air conditioned dorm on campus which made our place a very popular place to hang out !

When I lived in Florida 20 years ago, I used a miniature version of my pool heater (called a heat recovery de-superheater) with my air conditioner to make almost all of the hot water for my house for free.  Why on earth this is not done more commonly is also baffling to me. The payoff time of my investment was less than a year.  It easily saved me several hundred dollars a year in electricity.

Most people don't really understand how an air conditioner or heat pump works, so I guess it doesn't occur to people to use the large amounts of waste heat from their air conditioners for something useful instead of just throwing it away into the air.  Air conditioners / heat pumps don't "make" cold; they simply pump heat from one place to another.   You can pump the heat out into the air, or just as easily into a pool or to heat your water.

The economics of a heat recovery system from an air conditioner are much better than that of installing a solar electric system.  A semi close second is replacing a traditional electric hot water heater with a heat pump hot water heater, especially if the hot water heater is located in a garage or another space that you would want to cool and de-humidify anyway.  A regular resistive hot water heater gives you one unit of water heating value for every unit of electrical energy you put into it.  A heat pump hot water heater gives you about 3 units of heat for every unit of electricity that you put into it.

Yes, But they say the credit may be taken under section 48. Its a difference of where the tax credit is taken from what I can understand.  See this link with accountants discussing it on intuit:  https://ttlc.intuit.com/commun...