Question

I have a fairly inefficient gas fireplace. Is it difficult to replace it with a pellet wood fireplace? Also, is it worthwhile?

Asked by Brandon Stewart
Washington, DC

I have an open floor plan with an open staircase that goes 3 floors up. I have forced air from the top floor down. The design is essentially worthless. I want to put an efficient pellet burning fireplace in place of my inefficient gas fireplace. There is also a fireplace that is now been turned into an air return -- would it be possible to put the pellet stove in place of the air return? My thought is, since there is no smoke or waste, is it possible to put it in the main floor air return?

Answer

Florian Speier

Answered by Florian Speier

San Francisco, CA

Zeitgeist Sustainable Residential Design

October 27, 2010

Pellet stoves are the cleanest solid-fuel burning stoves. That does not, however, mean that they don't exhaust anything. They really are a very advanced wood burning fireplace that is:

  • automated,
  • gets about 85% efficiency, and
  • uses wood waste as a fuel.

The claim that they are carbon neutral stems from the fact that the wood, while growing as a tree, converted carbon dioxide into oxygen. If you burn the pellets (wood) you turn oxygen back into carbon dioxide. Seen as a life cycle, it is carbon neutral, but you are still reversing the positive effect the tree had on nature when growing by now burning the pellet.

As a result, you still have an exhaust pipe that you have to vent directly to the outside for a safe installation. In addition, I would strongly recommend a direct vent unit that takes its combustion air from the outside as well rather than using the air already in your house for much better efficiency.

In general it is tricky to evenly heat a house that is open over three stories.

There are three approaches for more efficiency in open multi-story floor plans:

  • Heat mainly the first floor, and have a very limited number of outlets in upper floors.
  • Use as much radiant heat as possible.  Heating surfaces, rather than air slows the process of rising heat significantly.
  • Circulate the air back down: an air intake or two on the top floor, a pipe down to the first floor with outlets there. Alternatively, install large ceiling fans in the open space.

I hope this answers some of your questions. You are welcome to send me your floor plans and budget so I can recommend the best solution for your specific case.
 

For more information:

Read Lee Hall's Q&A "What is the greenest, best fireplace replacement?"

Tagged In: heating cooling, fireplace

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