Is a gas fireplace blower fan an energy-efficient investment?
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In reading some of the prior blogs concerning the issues surrounding a ventless fireplace I was struck by the strong feelings for both positive and negative positions on a ventless design. My question actually pertains to the energy efficiency and advisability of adding a blower fan set up to a fireplace . Does a blower fan make the fireplace much more efficient in terms of using the BTU’s created by combustion of gas? It certainly seems that it should. It also seems that a blower fan would exacerbate the distribution of negative byproducts if that is in fact an issue. Can a blower fan be used in both a vented and unvented firebox?
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Replies
I have a vented gas fireplace, with a blower. The blower spreads the heat, but even without the blower, (when the power has been out) it heats pretty well. I'd get a blower.
I don't know why a blower would do much for efficiency. In fact, since it uses electricity, it may be a bit less efficient.
Invented gas appliances are illegal in some places. A blower isn't going to reduce any air quality problems created by combustion. I would never install an invented fireplace, even if local codes permit it.
Stephen
I understand that a blower fan uses electricity but the blower allows the BTU's of gas combustion to be placed back into the house rather than lost to the outside via the chimney in a vented fireplace. My question really centers on whether a vented fireplace with blower fan can be an economical way of heating my home as opposed to relying on the central heating system. If the BTU's of gas combustion can be economically harnessed with a blower fan for home heating requirments it seems that every fireplace should have a blower fan. What am I not understanding in this view? Whether the fireplace with blower fan should be vented or unvented is a related issue
The blower just pushes the warm air out into the room. With a vented heater, a fan doesn't capture whatever heat goes out the vent. I doubt you get any more btus to stay in the house by using a fan, but you certainly spread the heat around.
With an unvented heater, all the heat stays in the house, along with the products of combustion.
Like any point source heating appliance, a gas fireplace can heat a single room, so you can choose not heat the rest of the house. I'm sitting next to a wood stove that heats the space I'm in, so the boiler isn't running. I often use our gas fireplace in a similar manner.
W. Timothy,
So called "ventless" gas fireplaces use your home as a chimney. They are illegal in some locations and are not recommended if you care about indoor air quality. For more information, see:
A Ventless Gas Fireplace Doesn’t Belong in Your Home
Avoid Unvented Gas Heaters
A vented gas fireplace is not an efficient way to heat your home. While a high-efficiency furnace is more than 90% efficient, the efficiency of gas fireplaces ranges from about 30% or 40% (for fireplaces with a B-vent) to slightly over 70% (for the most efficient direct-vent models).
If you want information on the most efficient gas fireplace models, check this resource: Direct-Vent Gas Fireplaces.