Pellet stoves can be very effective at heating individual rooms or, in some cases, entire homes. But sizing a pellet stove properly is critical.

Though the physical size of a stove may be a concern if you have limited room where you want to put it, the primary issue in sizing a pellet stove is its heat output. If a stove’s heat output is too little, it won’t heat effectively. If its output is too high, its heat can consume too much fuel and become uncomfortably warm.

Pellet stoves are sized according to their heat output range, measured by BTUs (British thermal units) per hour. (For more about this, see What Is a BTU?) Pellet stoves may output from as little as 8,000 BTUs per hour to 90,000 BTUs per hour or more. Obviously, with this huge range, your choices are many, so finding the appropriate size for your home can be tricky.

Why we like it: • 3-Sided bay window, wood-fire-like flame • One load of pellets heats up to 45 hours • Thermostat control

When comparing BTU output between various stoves, be sure you’re clear about each unit’s overall efficiency, that is, how much heat it delivers to the room (not including heat that goes out the chimney).

Most of the time, it’s best to get the help of a knowledgeable dealer when sizing a pellet stove because many variables come into play for proper sizing. These include the stove’s location, how open the home’s rooms are to one another, whether a blower or other form of heated air distribution is available, how well the home is insulated, whether the stove will be providing primary or supplementary heat, and so forth. When meeting with a dealer, be prepared to discuss all of these issues.

Here is a helpful rule-of-thumb:

A stove rated at 60,000 British Thermal Units (BTU) can heat an open-plan 2,000 square foot home.

A stove rated at 42,000 BTU can heat an open-plan 1,300 square foot space.

Obviously, the location has a great deal to do with how effectively a stove will heat. A central location will make it much more possible to reach rooms throughout the house. For more about this, see Where to Place a Freestanding Pellet Stove.

Even then, it is often important to have an auxiliary method of heating, both because there may be times when it isn’t possible to burn pellets and because some rooms may be too far from the stove for delivery of heat.