What’s the heating capacity for a pellet appliance?

This depends on the amount of BTUs your pellet appliance produces. The great the level of BTUs/hour, the more heat will be generated and the more space it will heat.  On full power, some pellet stoves can produce between 40,000 to 45,000 BTUs per hour. You can adjust the BTU output and turn it down to heat a smaller area. Normally, a small pellet stove will run on around 8,000 to 28,000 BTUs/hour. A large pellet stove can produce up to 70, 000 BTUs/hour. Pellet appliances can heat areas from 300 to an impressive 3,000 square feet.