Heating your home with wood can be a great option…if it is done correctly. Before switching to or adding wood heat, here are some key questions you need to answer first.
Is heating with wood a lower cost heating option than my current energy source?
Several things will affect your heating cost: Fuel costs, appliance combustion efficiency and availability of wood fuel. In the publication, “Wood Heating Appliances for Homes and Businesses” (link under Essential Reading) on page 16 is a worksheet that can be used to determine the cost for a different energy source. Table 2 on page 11 contains some of the information needed for different types of fuel (energy contents, seasonal efficiencies). In general, natural gas is the least expensive energy source, followed by wood but it depends on the energy cost relative to other fuels. Using wood energy for heating will reduce costs by 30 to 50% compared to the cost of propane based on Jan 2015 costs.
Energy Efficiency First
Wood stoves, furnaces or boilers cost thousands of dollars to purchase and install. If you are concerned about high energy cost, you should have a home energy audit done FIRST to help identify potential savings. Things like adding attic insulation, replace weather stripping around windows and doors or replacing an inefficient furnace can reduce energy cost too and often with a faster payback than buying a wood stove. Energy Efficiency measures can also reduce the cost of a future wood burning appliance.
Cord wood, wood pellets, wood chips … Which is best for my application?
If you have a wood lot and are capable of physical labor you can harvest your own cord wood, transport it, stack it, allow it to dry and then use it for heating. Some think cord wood is free but it requires equipment (chain saw, vehicle, wood splitter…) and time to harvest. The value you place on the wood to rationalize the cost should be what you could sell the wood for. Wood also requires labor when you want heat because someone has to be available to stoke the wood combustion appliance and remove ash. Stoves are available to heat a single room to a boiler or furnace that can heat a house and outbuildings.
Wood pellets are typically purchased because of the additional equipment needed to produce the pellets. Pellet burning appliances are self-stoking, only requiring a hopper to be filled possibly once per day but can be automated to maintain a full hopper from a bulk bin. Since they are self-stoking the rate can be varied to better match the heating needs versus cord wood use. Pellets can be purchase in bags from many retailers or delivered in bulk from a pellet manufacturer or local distributor. Bulk deliveries will require some type of bulk bin to hold them. Pellet stoves are available to heat a single room, to a boiler or furnace to heat a large house or multiple homes. They can be located inside or outside and some have automatic ash removal.
Wood chips are readily available in some regions from limb wood from logging, from maintaining urban trees in cities and villages or a by-product of producing wood products. There is competition for wood chips as a landscaping material or animal bedding for dry materials but are generally lower cost per ton than other wood sources. Wood chips are typically not used for residential applications because of the extensive equipment needed for handling the chips for feeding a boiler. Wood chips are automatically fed into boilers, reducing labor and often have automatic ash removal.
Wood stove, indoor wood boiler, or outdoor wood boiler…which is the best appliance for me?
The choice of a stove, indoor boiler or furnace or outdoor unit will depend on your goals. Having a stove will heat the immediate area but the heat won’t typically get distributed to other parts of the home, evenly. So while you only need a t-shirt in the living room, you may need a long sleeve shirt and sweater in the furthest room from the stove. A furnace or boiler can be connected with your existing heating system to provide more even heating throughout the home. When the house thermostat calls for heat, the heating system will use the heat from the wood burning appliance first and if it can’t keep up, then the existing furnace or boiler would turn on to maintain the home’s temperature. The choice of inside or outside depends on the availability of space indoors and tolerance to dust and dirt. If using cord wood, there will be bark and dirt that falls off the wood each time it is handled. Wood pellets are cleaner but to create some dust. They also have lower ash contents so less ash to dispose of.
Firewood or wood pellets…which is best?
Firewood or cord wood can often be acquired locally from farm hedge rows or wood lots but requires physical labor to harvest and planning as it takes 1 or 2 summers to dry wood below 20% moisture so it is suitable for burning. It also takes some equipment; chainsaw, splitter and a vehicle to move the wood. If you don’t want to cut down trees yourself or don’t have access to a wood lot, some loggers sell truckloads of logs that aren’t suitable for lumber. Burning wood in a stove provides a cozy warm environment but someone needs to stoke the stove or boiler to keep the heat coming. If you are using cord wood as your primary heat, this means one may need to stoke it in the middle of the night or get up in a cold house in the morning. If one travels, then you’ll need to find a friend to keep the fire going. Cord wood also produces more ashes than wood pellets although ash can be spread on gardens and lawns as fertilizer.
Wood pellets are available at many retail outlets such as hardware, home improvement, and farm stores in 40 or 50 pound bags. Many outlets offer discounts during the summer for a one ton pallet of bags. Pellets are also available in bulk either delivered by truck to your bulk bin or in bulk bags that hold one to one in a half tons of pellets. Pellets burn clean, producing little smoke, and contain low ash contents so less waste to dispose of. Pellet burning appliances are self-stoking so no one needs be nearby to keep the heat coming and some can be setup to fill from a bulk bin automatically allowing many days of operation with minimal labor.