Q: What type of new furnace should I get? My existing oil furnace has a problem and I’m getting an oil smell in the house. My oil tank is currently 15 years old, and my service technician says I should switch from oil to propane. I live in an 1800s farmhouse so it’s not cheap to heat.
A: I agree with your furnace tech about the propane, and you definitely can’t use your current furnace the way it is. The smell of oil in the house is a strong indication that harmful gases are entering your home. You’ll need shut off the furnace immediately and use some other kind of backup heat until you get it replaced. It’s too bad that furnaces never break in the summer!
All else being equal, propane is usually less expensive to heat with than oil, depending on market prices. That old tank of yours wouldn’t pass inspection either, so it will need to be changed, too. Propane also eliminates the danger of an oil leak and contamination of your basement or yard. Modern propane furnaces are about 95% efficient and they don’t need a chimney – just a plastic pipe sticking out of the wall of the basement.
You’ll enjoy cost savings by replacing an old oil furnace with a new propane model, but your real gains will probably come from upgrading the insulation in your house. This is important. Attic insulation is the easiest to upgrade and offers the quickest payback. Do you know what depth of insulation you have in your attic? Here in Canada, where I live, 22″ of fibre-based insulation is not too much. Insulating walls is more challenging, but also worthwhile.
Various programs around the country also provide financial help for specific upgrades. You can learn more about Canadian programs from NAIMA Canada (http://www.naimacanada.ca; 613-232-8093). In the USA, the Department of Energy publishes several lists of grants that could reduce the cost of insulating homes. (https://www.grants.gov/learn-grants/grant-making-agencies/department-of-energy.html)
Older homes like yours often have hollow wall frame cavities with no insulation. That’s probably one reason your home is expensive to heat. The video below shows how slow-rise spray foam insulation injection can do an excellent job boosting insulation levels in walls. This is one of the only verifiable ways to upgrade the insulation in old walls. Click below to watch.