Heat Pump Water Heaters at Avant Garage
The Avant Garage project has a unique site condition that has caused us to re-examine the method in which Postgreen Homes heats the domestic hot water in each of its homes. There is just enough shading surrounding the site on the roof of the Avant Garage to dissuade us from installing our typical two flat panel solar thermal array. For this reason, we put on our research caps and came up with a new water heating solution that still fits our strict requirements of budget and performance.
After a few days of research, we decided that some of the new Heat Pump Water Heaters being offered were the best fit for our homes. These water heaters use the same heat pump technology that our split ductless heat pumps used for heating and cooling our homes. Rather than creating heat from scratch from an electric element in the water tank, the heat pump water heaters exchange heat from the surrounding air. They are able to reach efficiencies as high as 235% compared to a typical electric hot water heater that will be between 90% – 95%.
The top two choices for Heat Pump Water Heaters on our list are the GE GeoSpring Water Heater and the Rheem Hybrid Electric Water Heater. Both come in 50 gallon options which should be sufficient for any family of four, bost nearly identical specs. Each model also costs about $1,200 – $1,400 according to our current research.
Table from the ACEEE (American Council for an Energy-Efficient Economy) on Water Heating Life Cycle Costs:
|Water Heater Type||Efficiency (EF)||Installed Cost||Yearly Energy Cost||Total 13 Year Cost|
|Electric Heat Pump Water Heater||2.20||$1,660||$190||$4,125|
|Condensing Gas Storage||0.86||$2,000||$244||$5,170|
|High-efficiency Gas Storage||0.65||$1,025||$323||$5,220|
|Conventional Gas Storage||0.60||$850||$350||$5,394|
|High-efficiency Electric Storage||0.95||$820||$439||$6,528|
|Minimum Efficiency Electric Storage||0.90||$750||$463||$6,769|
|Solar with Electric Backup||1.20||$4,800||$175||$7,072|
This table above is actually quite sobering for us. We rearranged it to be sorted from lowest total cost of operation over a 13 year period to least. You can clearly see that the heat pump water heater is at the top of the list with our standard to date Solar with Electric Backup at the bottom of the list. This is due to the high install cost of Solar which is brought down by Federal and State incentives, but it’s reassuring to see these stats given our new direction in water heating technology.
These units will also serve double duty in our future homes with basements as they naturally cool and dehumidify the surrounding air. It’s almost like a free mini air conditioner in your basement during the summer that will help keep it from getting too damp and musty feeling.
That’s it for water heating for now. Let us know what you think of our new direction in the comments.