Tuesday, August 9, 2011

Follow-up on Air-source Water Heater

As a follow-up to my post from last October (http://wormmainea.blogspot.com/2010/10/water-heater-wrap-up.html), I am providing an update on my experience with the GeoSpring water heater.

The air-source heat pump is working great.  I haven't purchased oil since February 16, and since last May (May 2010) we used only 370.1 gallons of oil. That is a 28% savings (370 gallons vs 517 gallons [average from previous 2 years]). I realize that not all of that is due to the GeoSpring-- we did a lot of air sealing in 2010. But, my boiler has been off since May 15, 2011.

How has this impacted electricity use? That was my biggest question, too.

Here are my results of my electricity consumption for 2011, 2010, and 2009 (in KWH/day):

Month 2011 2010 2009

May 17 18 17
June 19 21 18
July 18 26 20

Do you see a difference? Neither do I!

I think this may be due to replacing the dehumidifier with the GeoSpring (which cools and dehumidifies while it heats the water).Same number of people in my house. Still taking hot showers.

I think this is wonderful. Since I typically used around half a tank of oil each summer (May to October), I am saving around $340/year (100 gallons * 3.40/gallon). The GeoSpring cost me around $2500 (for unit, installation and less state rebate). The ROI is 7 years, assuming oil prices stay level (something I very much doubt). I can live with that. Realize that we had to have a lot of electrical work to accommodate the installation-- your ROI may be lower!

I see this as a very successful energy saving investment. I hope more people consider this as an option.