Air Source Heat Pump
It started when, after a visit from our technician to perform annual maintenance of our heating equipment. I own a two family home in the Milton / Mattapan/ Hyde Park area. We use #2 fuel oil in an oil fired burner with a steam radiator heating system.
As he was leaving, he pointed to the service tag that he’d filled out and attached to our boilers and said, you are getting really low efficiency out of those boilers. He mentioned that it was an average of 75%. As he was leaving, I pictured me feeding $225.00 into my burner each month. To be honest, I’d noticed that tag after each of several previous yearly preventive maintenance visits, 78, 77, 76%, it got progressively worse, but somehow, it hadn’t had the same impact.
Lets Back Up a bit
Back to the Present
All of a sudden that 25% inefficiency began to bother me. I started picturing myself shoveling money into an Oil fired boiler. So I started to do a little research.
One of the first things I learned is that 30% of the total US Building energy resources are devoted to heating. Which primarily includes Natural Gas, #2 Fuel Oil, and electricity. Of those the most expensive is electricity. Actually there are some lessor used, more expensive, fuels, but in New England, they aren’t significant enough to mention here.
So instant expert huh……Hardly
But I know more than the average homeowner. In a blind world, the one eyed man is KING. And I know where to go and who to ask for help and explanations.
So here we go, Air Source Heat Pumps (ASHP)’s which have been used in the south for years, but have only recently become viable for use in the colder climates. During research for this article I found white papers supporting ASHP’s for use in such extreme climates as Mineapolis, Minnesota and The Alaskan Yukon Territory. They are also being used effectively in Maine. In the interest of full disclosure, The Yukon paper recommended that ASHP’s be used as supplemental systems.
There are several major providers of the equipment, Next Step Living (NSL) who performed my audit, represents Fijitsu. (others such as _____ are recommended by ____) and after their assessment of my home, NSL recommended two systems, one for my upstairs apartment and one for my own. After no interest loan financing for all the equipment and labor, my overall heating costs go from 750 dollars a month to 500. The 250 dollar savings will more than offset the increase in electric costs associated with operating mini split year round, for cooling in the summer. The heat pump because of its co-efficient of performance will use about 1/3 of the energy used by a simarly sized electric heating system. This is for 7 years, the life expectancy of the equipment is about 25 years.
The upstairs unit, occupied by my elderly mother-in law, would save almost double because, she stays home all day, and likes it toasty.
One other thing, as previously discussed, ASHP’s are recommended as supplemental heating in the coldest climates of the Yukon, but here in New England, In the rare event that temperatures drop below 15 degrees NSL recommended that I retain my existing legacy system, and use it to provide supplemental heating. The challenge would be using a full tank of #2 fuel oil before it “spoiled”. According to Historical records provided by the NOAA, the average low temperature at Logan Airport since 1972 has been 22 degrees.
Besides the basic air-source heat pump, there is also a ground-source (geothermal) heat pump. Ground source heat pump systems extract heat from deep in the ground rather than from outside air. The advantage to air-source heat pumps is that they are far less expensive to install compared to ground source heat pumps, and they can do the same job.