I really wish they would advertise heating capacity different. it is kid of miss leading. I know they read btu's but, when most people see 1500 sqft, generally they say well my house is 1500 sqft, so it has to heat it. I am sure the advertised sqft is tested in ideal conditions and an energy star rated room. If they would just remove the sqft capacity it might make people research a little better. and also will help with over sizing.
AMEN. Our Napoleon NPS40 is rated to heat up to 2000 sq. ft. and it produces about 8500 - 42,500 BTUs. I would assume that the 42,500 BTUs are produced when the stove is on its highest feed setting, 5 out of 1-5. The manual recommends rather strongly that the stove not be run on its highest setting nor on its lowest setting, but on a feed setting of 4.
We were sold this stove with the understanding that it has adequate capacity for our house.
We have 1410 sq. ft. of poorly insulated envelope (here I go again, brick/block and plaster with no wall insulation, sorry Regulars and Mods, I type this so many times) that we are in the process of sealing up with caulk, weather stripping and various other means. We are all on one floor with a circular floor plan, so moving heat isn't really an issue for us. Holding onto and stretching those BTUs is definitely an issue.
I've read recently on a Dept. of Energy web site about heating with wood, both cord wood and pellets, that a stove that produces at least 60k BTUs is probably adequate for 2000 sq ft, and that a stove that produces 42k BTUs is probably adequate for 1300 sq. ft. Thus our stove is barely adequate, actually a little undersized, for our house.
I have seriously considered trading it in for a stove that produces more BTUs, but as Webbie says, then we burn more fuel. The intersection of the amount of fuel burned vs. the stove's capacity to put out those BTUs is a function of the stove's feed rate, the capacity of the stove's heat exchanger system to deliver the BTUs from the fuel burned into the living space as heat, and the stove's construction and engineering to handle that amount of BTUs without over-firing the stove, damaging it and creating a fire hazard.
So, instead of trading in for a stove that burns more pellets per hour (more $$$ in fuel) and increases our infrastructure investment ($$$ in the transaction of buying one stove, selling it on the used market for a depreciated price, then buying another stove) we are working on the "hanging on to the BTUs we make" side of the equation.
Skye, you sound like you are in the *exact* same position that we were in 2008 when we bought our stove. Here's what we've done- it's happened in increments, so don't think that you have to do all of this today or tomorrow:
1. Check the insulation level in your attic- most homes have inadequate attic insulation. An insulated box or cover for your attic door helps a lot as well. Be sure to read cautions about insulating around and on top of can lights/inset lights.
2. Caulk caulk caulk and more caulk. Check for leaks and drafts. Door thresholds. Weather stripping. UL approved insulated inserts that go inside your electrical switch and outlet covers- our local Home Depot carries them. Also, child proof safety plugs to plug up the prong holes of the outlets you are not using on a continuous basis. Check every penetration point through your drywall or plaster walls or ceilings that you can safely reach. Many times the electrician or the person who installed the fixture cut a generous hole in the wall or ceiling for that fixture, a hole much bigger than the junction box that services that fixture. The decorative housing or face plate that you see on the wall or ceiling does not stop air leaks, and each of those holes in your walls and ceilings acts as a little chimney, sending your heat up into the attic. Ditto where plumbing fixtures and pipes penetrate the walls into your living space. As usual, cautions apply: do not put any insulating material nor any flammable material into the electrical junction box for any fixture, switch or outlet. Improper insulation over top of and/or around inset/can lights can cause a fire. Educate yourself about the safe way to insulate around electrical fixtures, junction boxes, inset/can lights, etc.
http://energy.gov/energysaver/articles/air-sealing-your-home
http://www.energystar.gov/ia/partners/publications/pubdocs/DIY_Guide_May_2008.pdf
3. Replacement windows if your windows are single pane, dated, leaky, etc. If that's not feasible, then weather stripping and window treatments: cell shades, thermal curtain panels, etc. We have cell shades and thermal curtain panels OVER replacement windows.
Each of these steps made a difference in the amount of heat we are able to maintain in the house. The big projects made a difference- but the little projects, sealing up penetration leaks- made a difference as well.