It’s “In like a Lion” as I sit here by the fire with snow falling all day. But if Puxatawny Phil is right, spring is just around the corner, so it may be safe to start putting together some results and make a few predictions about some energy matters.
You recall that we’ve embarked on an air-source heat pump experiment this winter. We previously heated our 3,000 sq ft house exclusively with about 1,000 gallons of oil per year, and more recently with about 1.5 cords of wood and about 500 gallons of oil. This year, on March 1, we are at about 1 cord of wood, 75 gallons of oil, and 1,500 Kwh of electricity ($230). The house has been, if anything, warmer and more comfortable than previous years.
We have had a milder winter. As of today and since Sept 1, we have experienced 4,566 heating degree days. That is the measure most widely used to gauge heating demand. At this point in the past two winters we were at 5,029 and 5,182, so to quantify the milder winter it has been about 10% warmer in terms of heating demand.
The air-source heat pump is rated at 12,000 BTU/hr. About the amount of heat that 20 feet of ordinary hot water baseboards would put out if run continuously for an hour. The wall cassette is located in the center of the first floor and has been on since about Oct 1. It is variable output so it continuously adjusts it’s energy use and output to respond to the inside and outside temperatures. The oil heat zone in that area has not come on at all since then, even when the outside temperatures went down to zero. I expect that we won’t use more than 10 more gallons of oil or $50 worth of electricity from here on out. There are only a few weeks of wood heating left as well – maybe 1/4 cord or so.
I know of several other people that are trying these things out, and all are experiencing the same amazing results. At this point, I can’t imagine why anyone would go to the trouble and expense to install a ground source (geothermal) system when this technology works about as well in our climate.
Another energy related project that I’ve been working on this year is improvements at the Wolfeboro Area Children’s Center. Last summer and fall, I helped implement a project to air-seal and improve the insulation in the main roof – about 5,500 sq ft. Then as winter set in, I monitored the heating system and installed new controls to improve efficiency and balance temperatures throughout the 11+ zones.
At this point, it looks like they will burn about 2,600 gallons of oil through next September vs 3,866 and 3,370 the past two years. That’s about a 25% reduction and not bad at all for a 13,500 sq ft building of that vintage. What is typically overlooked in projects like this is the big improvement in comfort. Temperatures are consistently 70-71 degrees throughout the building, regardless of outside temperature.
Hopefully, I’ll be putting more of my future efforts into blogging energy stuff than town politics, but the election is still a week and a half away.