Heat pump water heater intake from hot attic

Geo NR Gee · 05-01-16, 04:40 PM

A couple of years ago, I picked up a barely used Airgenerate ATI66 (out of business now) heat pump water heater. It was placed next to my gas water heater with the thought of hooking it up inline with the gas water heater to bring the temperature of the water up to a higher level.

I ended up pulling the gas water heater out and installing the hpwh this last week. It was the only hpwh that had ducting for the intake and exhaust air. The intake air is being drawn from the hot attic and the exhaust is dumped into the garage at the moment.

Today at 1pm, 86 degrees attic temp, 66 outside temperatures and 58 exhaust air at the heat pump water heater. This is just with a hand held temp. sensor.

The cost of the hpwh new was in the $3000 range without the tax incentives and installation. I paid $400 and installation was about $200 for power wire, breakers and plumbing. We have ran the dishwasher, clothes washer, and taken showers without running out of hot water.

While shopping at a local hardware store last year, the clerk rolled out a Boush whole house instant hot water heater for $40. marked down from $595. I was the closest to get my hands on it and had 4 other men asking me if I didn't want it. There was a few parts missing. They cost $145. for all the missing parts including shipping, so I now have $185 into it.

Would putting this Bosch unit inline with the heat pump water heat make sense for those days where using the hpwh doesn't make sense?

Electricity per kWh is $ .0955 tier one (first 600 kWh used) $ 0.11 tier two (above 600 kWh)

Gas is $0.443910
Gas Cost $0.405120
Other Natural Gas Charges & Credits $ 0.011270

05-01-16, 04:40 PM	#1
Geo NR Gee Journeyman EcoRenovator Join Date: Jan 2011 Location: Seattle Posts: 326 Thanks: 109 Thanked 23 Times in 18 Posts	Heat pump water heater intake from hot attic A couple of years ago, I picked up a barely used Airgenerate ATI66 (out of business now) heat pump water heater. It was placed next to my gas water heater with the thought of hooking it up inline with the gas water heater to bring the temperature of the water up to a higher level. I ended up pulling the gas water heater out and installing the hpwh this last week. It was the only hpwh that had ducting for the intake and exhaust air. The intake air is being drawn from the hot attic and the exhaust is dumped into the garage at the moment. Today at 1pm, 86 degrees attic temp, 66 outside temperatures and 58 exhaust air at the heat pump water heater. This is just with a hand held temp. sensor. The cost of the hpwh new was in the $3000 range without the tax incentives and installation. I paid $400 and installation was about $200 for power wire, breakers and plumbing. We have ran the dishwasher, clothes washer, and taken showers without running out of hot water. While shopping at a local hardware store last year, the clerk rolled out a Boush whole house instant hot water heater for $40. marked down from $595. I was the closest to get my hands on it and had 4 other men asking me if I didn't want it. There was a few parts missing. They cost $145. for all the missing parts including shipping, so I now have $185 into it. Would putting this Bosch unit inline with the heat pump water heat make sense for those days where using the hpwh doesn't make sense? Electricity per kWh is $ .0955 tier one (first 600 kWh used) $ 0.11 tier two (above 600 kWh) Gas is $0.443910 Gas Cost $0.405120 Other Natural Gas Charges & Credits $ 0.011270