What the Heck is a Wood Boiler?
As I write this, it is twenty degrees outside, and my family and I are nice and toasty! Best of all it’s cheap! Cheap! Cheap!! I am fortunate enough to have an inexpensive supply of wood, but even if I didn’t, it would still be less costly compared to buying heating oil, natural gas or propane.
An outside wood boiler, also known as an OWB, or an outdoor wood burner, does not actually “boil” the water. Water temperatures never reach boiling, although wood boilers commonly operate in the 160-185 degree range.
The water is heated in the boiler and is circulated via a pair of 1 inch pipes to your home, where the heat is transferred via a heat exchanger to your existing system. The existing system may be a forced air or hot water/boiler system.
Decreasing Smoke Emmissions Makes You A Better Neighbor!
Smoke Pollution is a nuisance for some wood boilers depending upon your location, and is also the single biggest point against their use. There is no way to entirely eliminate smoke, however you can signifigantly reduce it by following these suggestions:
- Size the heat exchanger correctly, or turn down the thermostat on the boiler. Overkill is a waste! If you find that your indoor water temp is around 140 degrees, you may be wasting wood, and creating unecessary smoke. You will also be shortening the lifespan of the wood boiler.
- The less you have to open the door to add wood, the less heat you waste. I run my water around 120 degrees. I am amazed at the diference in wood intake. Maybe on a smaller home it isn’t as signifigant, but on my monstrosity of a house, it was very noticable.
- Adding a fan near the bottom of your exhaust stack helps move and disperse the smoke.
- Lengthening the exhaust stack as much as possible will keep the smoke higher, also helping to disperse.
- One of the biggest “stretches” by wood boiler manufacturers is the concept of how often you add wood. I’ve heard it said, add once every 12 hours, 24 hours up to 96 depending on the efficiency and size of your home, as well as the wood or biomass boiler model.
It is true that you can add a bunch of wood and walk away for many hours. However, I’ve found that you will get a better, less smokey burn, by adding wood more frequently in smaller amounts. Bad burn practices creates angry neighbors, which in turn leads to poor public opinion and perception of outdoor wood boilers.
If more first time wood boiler users are aware of this from the start, this tip alone will save tons of headache.
The brazed plate heat exchanger pictured here is used for hot water applications, and a radiant heat exchanger is used in forced air applications. You can save big bucks buying these direct on the net. You will pay a premium if you purchase them with your “installation kit.”
The same principle applies for the feed and return lines, as well as the fittings, and pump.Check out the Sidearm plan on my e-bay section. A sidearm exchanger will heat hot water for home use, saving a ton of money in electricity or gas. For a more complete list of items and tips visit the link at the top of the page. I guarantee you will save money!