Chapter 8: Wood as a Heat Source
How does heating with wood stack up? It depends somewhat on the method you use to heat with wood.
Ways to Heat With Wood
Wood-burning systems can be located indoors or outdoors, and there are a variety of systems available for wood heat, including:
- Stoves. The most popular option is an indoor wood- or pellet-burning stove. These function as space heaters because they need no ductwork. They are often located in the center of a house.Placement is important because a pellet or wood heater needs space for both the stove and the chimney. The room with the stove is the warmest spot of the house. Therefore, the stove should be in a busy area, such as a family room, dining room or kitchen.Open concept floor plans are well suited for wood stoves because warm air flows freely. A 2,000 square-foot house needs a stove rated at 60,000 BTU.
- Indoor forced air furnaces. The design of a wood or pellet forced air furnace includes a firebox to burn the fuel, a blower to disperse the warmed air and a chimney or smokestack to handle gas emissions. These furnaces are usually in basements or utility rooms, and the system pushes warmed air through ductwork.Heat cannot be stored, so homeowners must add fuel regularly to maintain heat. This necessity is inconvenient for people with schedules that vary significantly or keep them away from home a great deal.
- Hydronic systems. A hydronic system, or wood-fired boiler, sends hot water through pipes. Individual room radiators often distribute the heat.Many of these boilers also heat water for the entire house. Some systems have hot water storage tanks that help maintain consistent temperatures throughout the day.
- Outdoor wood furnaces. As indicated by their name, outdoor wood furnaces are not located inside the homes they heat. Instead, they consist of a firebox surrounded by water, and warmed water goes through underground pipes to the home. Once there, radiators or heat exchangers with ductwork distribute the heat.Outdoor furnaces have some advantages. Wood, ash and dirt are kept outside the home. The firebox usually also has enough space to burn large or oddly shaped wood chunks. Unseasoned or wet wood is usable with outdoor furnaces as well.
Wood Burning Worries
While there are advantages to wood burning systems, there are also many concerns. On the whole, they generate more air pollution than other heating fuels. The circulating particles and soot can also lead to respiratory issues if people inhale them.
Vulnerable populations, such as infants, children and people with heart or lung disease can be seriously affected by wood-burning byproducts. Both the U.S. Environmental Protection Agency (EPA) and individual state bureaus have set emission standards for wood burning systems.
Fire is also a potential hazard if homeowners do not properly operate wood-fueled heating systems. Outdoor furnaces have a better reputation because if a fire occurs, it is outside the house. Precautions should still be taken even if the furnace is not located inside the home.
Wood Pros and Cons
What’s the heating oil versus wood synopsis? Depending on the model, wood- or pellet-burning stoves are 65 to 83 percent efficient. Indoor furnaces come in a little lower. An outdoor furnace has a 50 percent efficiency rate.
One advantage to heating with a wood burning system is if the wood is readily available, it’s traditionally less expensive than electricity, natural gas or heating oil. However, installing a wood heating system can be a significant expense. Homeowner’s insurance may go up as well. Another concern is the increased air pollution from using wood as heat above other methods of heating.
The average annual cost to heat with wood is difficult to determine. Wood fuel prices differ greatly by location. In addition, some individuals harvest their own supplies at no cost.Download the full guide!