Moved into a new house a year ago August. It's about 2700 sq. ft and
has dual zone gas heat. We also have a gas fireplace in the family
room where we spend most of our time. Last winter we used the
fireplace alot and were slammed with utility bills. Now that the gas
prices are supposedly going up yet again, I'm now wondering how much
of my bills are due to the gas fireplace. In other words, is it more
efficient to use the gas furnace to heat the downstairs to a
comfortable temperature or lower the thermostat and use the gas
fireplace? It's a majestic fireplace...not sure of the model. Any
advice or direction on where to look for this type of info would be
appreciated.

Mike wrote in message
news
Moved into a new house a year ago August. It's about 2700 sq.
ft and
has dual zone gas heat. We also have a gas fireplace in the
family
room where we spend most of our time. Last winter we used the
fireplace alot and were slammed with utility bills. Now that
the gas
prices are supposedly going up yet again, I'm now wondering how
much
of my bills are due to the gas fireplace. In other words, is
it more
efficient to use the gas furnace to heat the downstairs to a
comfortable temperature or lower the thermostat and use the gas
fireplace? It's a majestic fireplace...not sure of the model.
Any
advice or direction on where to look for this type of info
would be
appreciated.

If it is an open fireplace, it will probably suck more heat up
the chimney than it provides to the house.

Bob

No chimney..it's a vented gas fireplace with a blower.

On Thu, 14 Oct 2004 15:25:28 GMT, "Bob"
wrote:


Mike wrote in message
news
Moved into a new house a year ago August. It's about 2700 sq.
ft and
has dual zone gas heat. We also have a gas fireplace in the
family
room where we spend most of our time. Last winter we used the
fireplace alot and were slammed with utility bills. Now that
the gas
prices are supposedly going up yet again, I'm now wondering how
much
of my bills are due to the gas fireplace. In other words, is
it more
efficient to use the gas furnace to heat the downstairs to a
comfortable temperature or lower the thermostat and use the gas
fireplace? It's a majestic fireplace...not sure of the model.
Any
advice or direction on where to look for this type of info
would be
appreciated.

If it is an open fireplace, it will probably suck more heat up
the chimney than it provides to the house.

Bob

Great question - I would also like to know the answer. I have a similar
vented gas fireplace but without the blower. It uses outside air for most
combustion (Dual walled chimney out wall) but does not have fully sealed
doors so I expect it does pull some room air for combustion as well.

Mike wrote in message news
Moved into a new house a year ago August. It's about 2700 sq. ft and
has dual zone gas heat. We also have a gas fireplace in the family
room where we spend most of our time. Last winter we used the
fireplace alot and were slammed with utility bills. Now that the gas
prices are supposedly going up yet again, I'm now wondering how much
of my bills are due to the gas fireplace. In other words, is it more
efficient to use the gas furnace to heat the downstairs to a
comfortable temperature or lower the thermostat and use the gas
fireplace? It's a majestic fireplace...not sure of the model. Any
advice or direction on where to look for this type of info would be
appreciated.

On Thu, 14 Oct 2004 13:52:41 -0400, someone wrote:

No chimney..it's a vented gas fireplace with a blower.

No way should a fireplace be more efficient than an actual boiler or
furnace burning the same fuel (if all are of equal vintage).

Generally, people only "save money" with a fireplace if the fuel for
it is cheap or free (e.g., burning their own wood rather than oil they
pay for), AND/OR they are heating a lesser area of the house.

Think about it, why invent boilers and furnaces if a fireplace is more
efficient. Being able to see the flames doesn't make it more
efficient! In your case, they all burn the same fuel, and try to
extract useable heat from it. There is nothing about the enclosed
furnace that would make it inherently less efficient than the open
fireplace, more like the other way around.

Mike wrote:
Moved into a new house a year ago August. It's about 2700 sq. ft and
has dual zone gas heat. We also have a gas fireplace in the family
room where we spend most of our time. Last winter we used the
fireplace alot and were slammed with utility bills. Now that the gas
prices are supposedly going up yet again, I'm now wondering how much
of my bills are due to the gas fireplace. In other words, is it more
efficient to use the gas furnace to heat the downstairs to a
comfortable temperature or lower the thermostat and use the gas
fireplace? It's a majestic fireplace...not sure of the model. Any
advice or direction on where to look for this type of info would be
appreciated.

If you can figure out the model, the manufacturer's web site should have
efficiency numbers. Efficiencies of the direct-vent units usually run in the
50% range, although a fancy unit with a secondary heat exchanger can approach
70%.

In general, you're probably better off running the furnace "normally", rather
than using the fireplace -- the furnace will be at least 80% efficient and won't
run anywhere near 100% duty cycle, while the fireplace will normally be "on" the
whole time you're in the room. Not cut & dried 'tho...depends on a lot of
factors.

Frankly, the easiest way to answer the question is to try both methods on
"similar" days (a full 24 hour period, so you take into account your nighttime
usage), and use the gas meter reading to decide which method is superior (if
either is -- the difference may be mouse nuts).

"v" wrote in message
...
Think about it, why invent boilers and furnaces if a fireplace is more
efficient. Being able to see the flames doesn't make it more
efficient! In your case, they all burn the same fuel, and try to
extract useable heat from it. There is nothing about the enclosed
furnace that would make it inherently less efficient than the open
fireplace, more like the other way around.

Well, there are a few other advantages to a boilers and furnaces. For
example, you don't need to have a fireplace in every single room, and you
can heat the whole house with a single thermostat versus firing up 13
fireplaces.. I suspect the invention of central heating systems was driven
more by convenience than efficiency.

Actually a *ventless* gas fireplace is probably a fairly efficient heat
source- since none of the heat is going up the chimney. If you only want to
heat that room, I would say it's definitely more efficient to use it, then
to fire up the central unit for the whole house.