Can someone explain to me how BTUs work. I have a EPA exempt newer stove. It has worked great for how we heat, only for a couple hrs in the evening and then most of the weekend. Its rated to hear 1500 sq ft and 110,000 BTUs. Ive been checkin out some EPA stoves for some longer burn times, and use less wood. I have been looking at a couple stoves that will heat a sq ft area similar to the one i have but the BTUs are much lower like 68,000. How would that effect the way i heat. Here is what i do now. We get home from work and light the stove at like 4-5 pm, and run it until we go to bed, it keeps the one end of the house pretty warm and the other end at least 65*. Which is fine. But because of where the stove is, its on a big enclosed porch that doesnt have a door with a dead bolt, the deadbolt door is the one coming off the porch into the house. So when we go to bed we have to shut the door so we can lock it. Which is fine cause by that time its burned down and we let the furnace take over for the night. What i would like to do is get a high eff. stove and either put a through the wall fan from the porch to the house so we can still lock the door, or get a real outside door for the porch. But i would like to load up the stove and let it burn all night. My current stove would not burn all night. But i high efficient would. But how to the BTUs compare and what would i notice going from a higher BTU stove to a lower? Not as much heat output? Longer heat up times? I dont know if i would want longer heat up times, cause when we get home from work we want it hot and fast. Thanks guys!