Heating your home with an outdoor wood boiler can be a great way to save both time and money during the winter months. Modern fossil fuel-based heat methods are almost always more expensive than wood, which can be sustainably harvested from your own land or purchased for a modest sum. Outdoor boilers allow you more flexibility than wood stoves, since they can burn almost any type of wood and help keep your house clean by leaving all of the bark, dirt and bugs outside.
Here are seven reasons you should consider an outdoor boiler:
1. Greater efficiency.
Outdoor wood boilers are often referred to as “wood gasifiers” because they technically burn the wood twice, extracting extra BTUs of heat energy that are otherwise lost up the chimney in a traditional wood stove. In the initial burn chamber, wood is burned as it would be normally, and the energy begins heating a thermal reservoir that will be piped to your house. The gas created in the initial burn chamber is then “re-burned” to extract additional heat energy from the volatilized gasses produced by the initial burn.
2. Works with softwood or hardwood.
Since the wood gasses are burned more efficiently in an outdoor boiler, you’re able to burn softwood, including fir, white pine, cedar and hemlock, all of which are dangerous to burn indoors in a normal wood stove. The re-burn helps prevent buildup in the chimney, and lowers the risk of chimney fire when burning soft woods. Still, it’s important to keep your chimney clean with a thorough sweeping each year.
3. Warm floors.
When you’re warming the air in your home, often you still feel cold as you walk around on cold floors. With an outdoor wood boiler, you use the heat generated for radiant floor heating, meaning that the floors stay toasty warm and slowly diffuse the heat into the room.
This means more consistent warmth, as the heat slowly diffuses throughout the room and helps keep your home at a constantly comfortable temperature.
4. Cleaner household.
An outdoor wood boiler means that all the mess, dirt, bark and bugs that accompany firewood stay outside in the boiler shed rather than coming into your house. Unless you have extra money to burn on clean kiln dried bug-free firewood, firewood in the house means extra mess in the house. Some homesteaders store wood in the basement, but that can create another problem in that it can continue to dry and release moisture in your basement – creating mold and health issues.
5. Less wood hauling.
With both the wood and the heat source outdoors, wood can be split and stacked once, outside under cover and ready for use, rather than having to be hauled indoors before burning. It’s already enough work to haul wood out of the woodlot; keeping it outdoors saves you a lot of time and a few slips on the ice during winter time.
6. Less cutting & splitting.
Outdoor boilers are generally much larger than in-home wood stoves, allowing you to use longer lengths of firewood. This means less cutting and splitting for the same amount of wood — a great labor savings! Feel free to use wood as long as your boiler will hold, but make sure that the wood is still split into small pieces, as the boiler will work much more efficiently if the wood is kept to a manageable size, avoiding wasted space and extra empty air pockets in the burn chamber.
Indoor wood stoves are dependable and generally easy to work, but they can be hazardous to small children playing nearby because of the direct heat source. They also pose a risk of chimney fire, which can catch and quickly spread throughout the house.
With an outdoor boiler, the risk is outdoors — and in a completely different building. They’re also generally safer because the re-burn process helps prevent chimney fires. Nonetheless, avoid burning garbage or excess paper in your boiler, which can send flaming ash into the pipe and potentially start a fire.
Downside of an Outdoor Boiler
There are also a few downsides to heating with an outdoor wood boiler. A traditional wood stove does not require electricity, while a wood boiler requires electricity to run both a fan to keep the gasifier functioning efficiently as well as pumps to conduct the heat to your house. With a little home ingenuity, both of these can be wired to run on DC power straight from off-grid batteries, but it’s still wise to have a backup wood stove in the house just in case power is out for an extended period of time.
The second major drawback is cost. While they’re inexpensive to maintain, the initial investment can be sizable. It’ll pay you back in efficiency and the ability to burn low-cost wood in the future, but in the short term be prepared to lay out some cash to get your outdoor boiler installed.
Have you ever used a wood boiler? What advice would you add? Share it in the section below: