Submitted by infinite_zero t3_10jb26c in Maine
We live in Wiscasset well off the main road, and have always had an oil furnace to heat our 2600 square foot home. Lately, the cost to fill the tank has rapidly risen past $1000.
Our house is quite old, but we have replaced the windows, roof and added insulation in the last few years to try and reel in energy costs. Unfortunately, though this has helped a little, it hasn’t had nearly the impact we had hoped.
My wife and I are far from wealthy and the rising oil cost has become a huge concern. It’s hitting the point now where we seriously have to look into alternative heating methods if we don’t want to leave the house after retirement.
I’ve done plenty of homework on the subject of energy-efficient heating and mostly see solar and heat pump as our options. Does anyone have experience converting from oil to either of these options in a similarly-sized home?
Edit: We use about 213 gallons of oil monthly and keep the thermostat between 63° and 65° F.
Edit 2: The heat is delivered via forced air. The ductwork was replaced 2 years ago so it should still be a modern level of efficiency and well-sealed.
AlternativeWay4729 t1_j5je4c6 wrote
Our old farmhouse isn't that large, about 2000 feet with a recent extension, but it has distant wings, so doesn't heat easily.
When we got it, it wasn't insulated. The previous occupants used 700 gallons oil and ten cords of wood a year. We didn't exactly convert the place from oil. The oil furnace is still there. What we did was make incremental improvements. First we put in a wood stove and used that instead of the oil hot air furnace for about 80% of the heat. Then in stages we air sealed and insulated: new windows and doors, R40 cellulose blown in the attic, four inches cellulose blown into the stud bays, and two inches R10 foam board over the entire outside. Spray foam on the upper four feet of the cellar walls and joist bays. Smarter thermostats for the furnace and baseboards. Every year for five or six years we did something to improve on air sealing and insulation. We did it all ourselves.
Then we built an extension that had R10 foam board and six inches cellulose in the walls and R40 in the attic. We added a heat pump in the kitchen where we can feed both wings, although not well enough to get to the far corners where we have electric heaters to top up. We added solar, 2.7kW/hour of sunshine, which cancels out some of the extra power needed for the heat pump and baseboards. Right now we use 3-4 cords firewood, less than 50 gallons oil, and our power bills go from $40 in summer to $100 in late fall and spring to $300 in January and February. Quite a bit of that is tank heaters and heat lamps for livestock and block heaters for a tractor, though. We measured their consumption with a meter and it is high, as much as $80/month. If we didn't want to keep stock then we'd have only $120 to $180 more electrical consumption/month in winter. Our power bills would top out just over $200/month. I estimate our total actual heating costs at about $1200/year. Right now we are replacing the furnace with an identical newer used model. We don't use it much -- we've gone only from from 1/3 to 1/4 of a tank so far this year. But when it's really cold we do use it to keep the house warm when we're not here. It sits in the cellar so it keeps the pipes from freezing. The old one is getting rusty because the 120-year old cellar is damp and floods occasionally. And the insurance company wants us to have one, even if we barely use it.
(Full disclosure: I was an energy academic before retirement. Now I'm just a grumpy handyman.)