Best for heating the general space the appliance is located in, for example many living rooms or studies with a range of 400-800 square feet.
Typically used for heating a large open space or a smaller home ranging from 800-1600 square feet. Burning over night is achievable depending on the model and conditions.
We are into the workhorse category. These have features such as side or top loading, designed to be used 24/7 with an overnight burn time. Typically best used in spaces ranging from 1600-2400 square feet.
Designed to be centrally located in a very large home. This is a very unique class. This is simply put X-Large square footage of 2400 plus.