I am looking at converting my wood fireplace to a gas one. However, I
noticed 3 styles.
1. Gas Insert - Too expensive for me
2. Vented Gas Logs
3. Ventless Gas Logs
I am attracted to the Ventless for these reasons. 1) I can close the damper
and save on heat going up the chimney. 2) Our house can use the water
generated by the fire. 3) It produces a lot of heat (as compared to a
vented). 4) It is affordable.
My only sticking point is the safety. We would only run it when we are awake
and when we are home. Given these circumstances, are they safe? I assume it
is like a gas stove.
Finally, what is the average cost per hour running it. I assume it depends
on BTUs ect. So is there a web site that can help me calculate monthly usage
Thanks in advance!
I have two sets of gas logs (both vent free) in my home now. They are safe.
I have a two story, with one set in the "basement" on a setback thermostat.
This keeps the floor of the second story warm and less heat ( 2001 vs 2002
) was used.
Most of the vent free units are 95+% efficient. They also have "oxygen
depletion sensors" that will shut the unit off in the event of a CO leak.
I also have two CO (carbon monoxide) detectors and have never had either go
The thermostat option added about seventy bucks to the set of logs , but
IMHO it was well worth every penny. Also, if I ever lost electricity, there
is no doubt that I could heat the entire house (2700 ft) with the two gas
Lowes had a set of 24" Vent Free for $200 that looked pretty nice.
Thanks alot. I've read posts similar to yours on other boards but wanted
confirmation. I've never seen them in use. Do they look nice? Authentic? On
average, how much do they cost to run per hour?
The set I use most often ( downstairs) is set on about mid range (if I set
it on high it will put you out of the room). I think we paid about $250 on
clearance for the set, and they do look real nice. I have even thought of
making a heat sensor audio circuit to reproduce random crackling :-).
No idea on what they cost to run. All I can tell you is we had a heck of a
winter last year (Ohio) and my place was nice and cozy throughout. The year
before, we fought with the thermostat trying to make it comfortable
downstairs without being 78 upstairs.
How much did you save on heating bill? I am thinking about buying one to
save my heating bill. Is yours a portable unit or is it something that
replaced your existing fireplace?
Do you have moisture problem? A ventless log can produce 1 - 2 qt or
water per hour. I have searched the web on ventless fireplace and some
people recommand against it because of the amount of water produced.
Furnace can have efficiency up to 95% or so. That's why I'm interested
in your saving.
I did not save a single cent on my heating bill BUT had no intention of
doing so anyway.... My ventless log set replaced a see thru regular
fireplace..which opened to both the rec room and to the living room..
Never noticed any change in the amount of mositure...BUT I can never run the
logs for a solid hour...even on the low setting because they produce way too
My sensors never go off either..BUT like I said I can not run the logs very
long because they produce too much heat......does a heck of a job removing
the chill in a room however..
Responses in line after this message.
I will never have a vent free appliance in my house. Period. After 2-3
years of constant use, the ceramics start breaking down. That will cause
production of CO.
Now, on with the show.
Wrong. The ODS have nothing to do with CO production. They are for sensing
too low of a level of oxygen (you know, the stuff we humans breathe?) to
support life. Anyway, all an ODS is a small pilot. Did I mention I will
not have a ventless appliance in my house?
Have you had them tested? What's the threshold of the units? Some units
won't go off until they have been exposed to 50+ PPM for 2 hours. Others
will go off from 'flicking your Bic' near them. Guess which one I have?
I do have a gas cooktop. Every time it gets turns on, my vented (instead of
recirculating) range hood goes on. The hood has an infinite speed
controller on it, so it's usually on real low.
These are my opinions. If you don't like them, ignore them. If you like
them, great! It's your money and your life.
Regarding ventless gas logs, I have read quite a few articles about the
potential of high CO emissions as well as adding more indoor pollution.
There are also many municipalities (including my own) that disallow ventless
gas logs (I think they're banned in Calif.?). I have also heard that the
flame is not as aesthetically pleasing as in a vented one. Apparently, the
flames stay quite low and have little color variations.
I have a vented gas log set and I can tell you that I can heat up my family
room (23'x15') quite nicely. I am quite pleased with mine. It looks almost
Just my .02.
I have had vent-free logs for a few years. I have no concern
about CO, because 1) it is not easy to damage a gas burner in
such a way that it generates significant CO except in an
oxygen starved environment, and the oxygen depletion sensor
is made to address that, and 2) I have redundant CO detectors,
one with a digital readout, just in case.
My grandparents lived 40 years in a home that was heated only
with vent-free gas heaters, as did many of their friends.
No one had heard of CO detectors at the time.
Some posters mentioned indoor air pollution. Gas logs
produce carbon dioxide and water vapor. Carbon dioxide
is inert, and water vapor can be a good thing or a bad
thing, depending on how tight your house is. If your
winter humidity levels are already high, getting vent-free
logs are a bad idea. If you home is too dry, then the
logs will help.
In all this time of use, the CO detector readout showed
a non-zero readout only on the first use of the logs.
It never got off zero again. The alarm threshold is 20,
as I recall.
Another person noted the downside: mine put out a *lot* of
heat, even at the lowest setting. You might want to get
a unit with a IR remote thermostat. For those occasions
when you are just wanting the aesthetic appeal of the logs
for a few hours, just open the damper and let the heat
go up the chimney.
It is my impression that the vent-free logs generally look
less realistic than the vented logs. However, you should
be able to look at any logs you are considering in operation.
Don't buy logs you can't observe.
A neighbor told me of what may be the best solution: a vented
gas log assembly that is nonetheless efficient. However I
think this is not just logs, but includes a free standing fireplace
with heat recovery design.
Keep in mind that most vented logs in modern fireplaces have
*negative* efficiency. That is, turning on the logs in a heated
home sends more heat from the home up the chimney that the logs
deliver to the home. A friend of mine could not understand
why her electric bill went through the roof last January when
she ran her vented fireplace all the time. "The heat pump ran
all the time!"
If you have a very old home with a fireplace that was actually
designed to heat the home, the situation can be better. If you
look at 200 year old homes, you will see fireplaces with large
openings and a rear wall that slopes slightly forward. The bricks
of the rear wall get warm and radiate heat into the room. Contrast
that with the nearly cubical fireboxes in most modern residential
Rick Matthews firstname.lastname@example.org
Department of Physics http://www.wfu.edu/~matthews
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