My wife mentioned that she only runs the zero clearance fireplaces and that our furnace has been off this entire heating season, unless we leave for extended periods. I think, she thinks, that the fireplaces are more efficient because the fireplace installers told her that they are..and she belives anything that “experts” tell her.
My question…are these zero clearance fireplaces really more efficient?
blue
Warning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information…don’t listen to me..just ask Gabe!
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"My question...are these zero clearance fireplaces really more efficient?"
Efficiency is the ratio of useful energy out, ie heating the house, to energy in the fuel.
Newer gas furnaces with electronic ignition are about 80% eff or better. Older ones are in the 60-70%. But that is based on a average fuel use. And if it has a standing pilot light and is only rarely used then the effective eff is way lower.
"zero clearance" does not mean anything in it'self. So it have any vents to get entra heat out of the unit (Heatolater style)? Does it have pipeing for external combustion air?
I don't have any numbers, but the eff can be all over the place.
BUT WHY DO YOU CARE.
What you are realy interested in is the cost of operation.
What is the wood costing you?
Oops Bill...I failed to mention that the fireplaces are gas powered. They do use outside air and they are on a programmable thermostat.
blueWarning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information...don't listen to me..just ask Gabe!
Probably 6 of one or 1/2 dozen of the other.Depends on the specifics of each unit.
Bill, I might dig up the data.
blueWarning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information...don't listen to me..just ask Gabe!
fireplaces are gas powered
Big oops in description there all right.
Like Bill and Bob also inferred/said, if you ain't burnin' free wood, a
FP is a big LOOSER!!!!
I don't know...the firplace guy claims they're more efficient than our furnace...which ain't nothing special...I mean we're not using a closed loop geothermal....
blueWarning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information...don't listen to me..just ask Gabe!
My guess is the gas fireplace will cost you more. I would bet the room with the fireplace is kept warmer than if you set the thermostate on the furnace to 70. Secondly, since circulation is poor you will have to run the fireplace more inorder to get heat to distant rooms. just my guess.
she only runs the zero clearance fireplaces and that our furnace has been off
Hooray for your wife (serious hurrah)
Ah, the bliss of past years!. Wood still essentially free except for chain saw gas. DW literally kept the home hearth burning for 35 years till she finally told me she was getting too old to cut/split/feed* the FP** with > 8 cords/year after she was 60YO, so finally installed a HP. (*well actually we shared the tasks, she did most the feeding, me the cut/splitting).
After the kids were about 10 YO, they got 50 cents to start the fire in the morning, $4/hr or $15/cord splitting (their choice of pay method) when they were teens (they be near 40 YO now)
Did measure the efficiency once in the 1980's by weighing the wood, measuring stack temp and flow, duct (yeah, ducted heat from FP) flow and temp, blower door type external draft delta, etc. Came to about 58% for burning dry alder for 40F outdoor temp.
** not a commercial zero FP insert, more like a power plant waterwall furnace.
PS: le's see - 40 years, $600 year avg saved, $24K saved.
Edited 12/12/2004 9:44 am ET by JUNKHOUND
JH...I'm gonna run that by my DW and see if she'll go for it...
blueWarning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information...don't listen to me..just ask Gabe!
I seriously doubt if they are more efficient: efficiency is basically the amount of BTU's produced by the flames and the amount of heat kept within the house and not sent up the chimney.
(The so called "ventless" combustion devices are "100% efficient" from that point of view, and are a terrific idea if you don't mind living in a chimney {G})
I find it hard to believe that a metal box with a fan added on to circulate some air around it could be more efficient than a furnace with presumably carefully shaped combustion chambers.
One reason is that efficiency depends in large part on the size of the flame being appropriate for the size of the combustion chamber - minor changes in flame size in relation to the combustion chamber can have significant effects on efficiency.
In my 90+, I can effect efficiency with minor, almost undetectable changes in gas pressure and thus flame size.
A suggestion: take an oven thermometer and measure the temp of the flue gases coming out of the furnace flue and the fireplace flues
As a very rough guide, the lower the flue gas temp, the better the efficiency.
I don't know about yours, but my church isn't a hotel for the holy, it's a hospital for sinners
Sojourners: Christians for Justice and Peace
Bob, my instinct is to agree with you.
I won't vouch for the forced air system though...
Everything is relatively new...about 1.5 years but...welll...I guess the forced air system is good....
What the heck do I know about furnaces and ductwork?!!!! Nothing!
Awright...I'm gonna do that oven thermometer thing. Wanna come over here and help me hump our oven up to the roof top?
blueWarning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information...don't listen to me..just ask Gabe!
It all depends... on the specific units and how you are using them. A sealed gas FP with external combustion air supply runs mid 70's to low 80's % efficient. New central furnaces run mid 80's to low 90's. You can pull the manuals on both - they should include the spec's.
OK, so that's the basics on the equipment. Now - what are you heating? If you just want to heat the room where the FP is it's going to be more efficient than if you try to heat the whole house with it. And vice versa.
wrudiger...I think your onto something.
It is kinda cold back here...
I'm going to pull the manuals and show her.
blueWarning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information...don't listen to me..just ask Gabe!
I know this won't make any differrence to the fiar haired Moadonna of your abode, but since you are comparing a furnace operating at 70-80% efficiency to an open flame operating at maybe 30% effeciency tops, you are not saving money.
But if she thinks she is, and if she is a typical female of this species, then by golly, who are we to tell her she is wrong.
Especially since, when she sits there gazing into the fire, she gets all romantic and gets motivated to rub you poor aching feet and works up from there...
Man, throw that darn furnace away, then when gas gets too expensive, you can start to have her take lessons from Mrs Junkhound, and she will then have stronger fingers to rub your
feet with, and a nice rouge glow on her cheeeks from the outside activity.
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Piffin...I like your style!
blueWarning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information...don't listen to me..just ask Gabe!
"But if she thinks she is, and if she is a typical female of this species, then by golly, who are we to tell her she is wrong"
You got that right. Ever notice how on the one hand women think you are a god, since they complain about everything and expect you to fix it. All the way down to removing spiders. BUt if they don't like your answer than they remind you that you don't know anything since you are not an "expert" electriian, plumber, etc.
???
So, You remove spiders by electrocuting them before flushing them down the drain, I see. You got both licenses for that?
LOL
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!