Outdoor wood boilers deliver heat for cheap
They're efficient, clean and will save you lots of money if you have access to a forest
If you live in the country with access to even a small forest, and you've got an interest in using wood to economically heat your home and outbuildings, you should consider an outdoor wood boiler. I've been heating my home, workshop and domestic hot water this way for 12 years, and installing this system was one of the best home energy decisions I've made. Even if you don't plan to heat with wood, you might still find the whole topic just plain interesting. It's like no other heating system you've ever heard of before.
Imagine something that looks like a small metal garden shed near your home. Inside this shed is a firebox that holds burning wood that heats water in the water jacket above. This hot water gets delivered to your home and outbuildings to radiators via insulated underground pipes, with cooler water returned for reheating in the boiler via a neighbouring pipe. This is the outdoor boiler system in a nutshell and there are three reasons I like it.
Lots of heat with minimal cutting and splitting of firewood is the first reason I like this system. The firebox in my boiler measures 34 inches wide by 44 inches long, so there's no need to cut and split firewood into small chunks. Make your wood as big as you care to handle and it works fine. In fact, I heat during the shoulder seasons mostly using junky pieces of dead trees that normally wouldn't be worth turning into cordwood at all.
And this brings me to the second reason I like my boiler.
You can't beat how economical it is to heat large areas with an outdoor boiler, as long as you consider your time spent cutting and preparing firewood as a bonus and not a burden. This is especially true for those of us who live in the country with no access to natural gas — the cheapest purchased heating energy source going. Propane, electricity and oil are the main retail options for heating out here, and these are roughly four times the cost of natural gas for a given amount of heat. This is why you can save enough money cutting your own firewood to “earn” the equivalent of at least $50 an hour if you're efficient with your wood-cutting efforts.
The third reason I like my boiler is the way it makes handling wood easier, and keeps my home cleaner. Stack firewood near the boiler as you cut it, and you only need to pick it up again once. And since the fire and ash are always outdoors, it's cleaner than dealing with ash from a wood stove inside your home. One big fire can replace what would otherwise require three or four wood stoves in different buildings and locations, so it's all very convenient. I spend 10 minutes twice each day emptying ash and adding more firewood. It's easy work, and cleaning the five-foot tall chimney once or twice a season is a breeze because you do it standing on the ground.
When I was shopping for a boiler more than a dozen years ago, I settled on a Canadian brand called Portage and Main. Their units are built in a Hutterite colony in Piney, Man., and after more than a decade of use, I find their design and workmanship outstanding. I did have a mechanical issue with my first unit about five years ago, but the company made good on its warranty and shipped me a brand new unit at no charge.
Another reason I like my Portage and Main boiler is how cleanly it burns. Some brands of outdoor boilers have tainted the reputation of this technology by putting out a lot of bothersome smoke. But good design and proper burning techniques can eliminate this problem, all while delivering homegrown heat you can count on.