Rumford retrofit?

[stoveliker]

Here you go.

The flame dilemma: A data analytics study of fireplace influence on winter energy consumption at the residential household level

This study investigates the effect of the presence of fireplaces at the household level independent of the function of ambiance and indoor air quality…

www.sciencedirect.com

It's 31 pct.
I'd take this with a 10 pct error. Still.
Perfectly fine to choose this - depends on what one values more.

 

[bholler]

I didn't think you were actually suggesting that heat loss from having a fireplace sitting there doing nothing is significant enough to motivate someone to get rid of a fireplace. Sure, a damper is not air tight. Neither is a house door, but most people want a door. Some people want a fireplace. I'd also stick a wool plug in the flue when not using it.

Yes, the two opinions have been expressed.

The fact of whether the OP's fireplace causes a NET loss of heat from his home and actively cools the home has not been measured.

Every fireplace sends air out of the house, and more so than pretty much every wood stove. However, it certainly is not the case that every fireplace actively cools the house more than the heat it generates, resulting in a NET loss of heat. If there is data to refute this, I would be interested in it, but it seems to be a phrase that is simply repeated without basis.

To be fair, you did not say there was a "net" loss of heat... just an "active" cooling of the home, which I suppose is technically correct. But by that rationale, every wood stove also "actively cools" a house. Though it obviously heats a lot more than it cools.

I have already acknowledged that stoves are obviously more efficient... and that they are better in every single parameter, except for one, which is the experience of an open fire. I do not advocate for a fireplace instead of a stove, or even to build new fireplaces in general. I just think it can be pleasant to keep a well built fireplace that is already there in addition to a stove.

However, this acknowledgement will never be enough for many on this forum. One must denounce the Satan that takes the form of an open fireplace.


I fully agree you would be the authority on the pricing of such jobs. But we should also not overestimate the credibility of this dude that needs "scaffolding and at least 4 men" to do what you said you would prefer to do alone... and with a reasonable explanation of your process.

You said the insert wont easily fit in a rumford (correct) and the advice on the stove and liner is certainly appropriate. It would be an especially good idea if the fireplace and chimney were junk. It is STILL a good idea if the OP doesn't want to use the fireplace.

I guess my point is there are costs already invested in the nice fireplace and chimney.
For me, the options ranked from worst to best are:

1) Fireplace
2) Stove
3) Fireplace AND separate stove

But the OP will decide what is best for them. The stove will work fine with either option, and it mostly comes down to the esthetics and setup, the cost differential, and if he wants to keep the fireplace or not.

You are missing the point that the op clearly said "I desire a wood insert or wood stove so that we can increase efficiency and so we can have a sealed, safe fire. " It certainly seems he made his decision before starting this thread you are pushing something he isn't interested in doing.

 

[N.E.K. - D.D.S.]

You are missing the point that the op clearly said "I desire a wood insert or wood stove so that we can increase efficiency and so we can have a sealed, safe fire. " It certainly seems he made his decision before starting this thread you are pushing something he isn't interested in doing.

He said his wife would like to just use the fireplace but he (for good reasons) likes the idea of a stove or insert.
It seems he has a reasonable option to do the stove and not shut down the fireplace which exists and is functional.
You provided insight on relative cost. He can go either way.

If OP is not interested keeping fireplace, then there is nothing to discuss. Do the liner and forget it. I just read his messages differently (reluctance to shut down the beloved rumford). I believe he was weighing the two options and says he has space for the stove next to the fireplace.

The only place where things broke down is this assertion that just keeping that fireplace is going to be detrimental even if he doesn't use it and heats with the wood stove. I think that is ridiculous.

Here you go.

The flame dilemma: A data analytics study of fireplace influence on winter energy consumption at the residential household level

This study investigates the effect of the presence of fireplaces at the household level independent of the function of ambiance and indoor air quality…

www.sciencedirect.com

I have to take a look at this when I get back home. I am curious about whether they are talking about total energy usage including wood in the fireplace (which is obviously inefficient compared to other heating methods) or if this is saying that homes use more energy to heat just by having a hole in the form of an unused fireplace and chimney. Those are two very different things.

I am open minded and will look into this.
Thank you for sending the reference.

 

[bholler]

He said his wife would like to just use the fireplace but he (for good reasons) likes the idea of a stove or insert.
It seems he has a reasonable option to do the stove and not shut down the fireplace which exists and is functional.
You provided insight on relative cost. He can go either way.

If OP is not interested keeping fireplace, then there is nothing to discuss. Do the liner and forget it. I just read his messages differently (reluctance to shut down the beloved rumford). I believe he was weighing the two options and says he has space for the stove next to the fireplace.

The only place where things broke down is this assertion that just keeping that fireplace is going to be detrimental even if he doesn't use it and heats with the wood stove. I think that is ridiculous.

I have to take a look at this when I get back home. I am curious about whether they are talking about total energy usage including wood in the fireplace (which is obviously inefficient compared to other heating methods) or if this is saying that homes use more energy to heat just by having a hole in the form of an unused fireplace and chimney. Those are two very different things.

I am open minded and will look into this.
Thank you for sending the reference.

The vast majority of fireplaces take more heat out of the house when burning than they add. A well designed Rumford may not but that is a big if.

 

[LongshoreMatt]

I didn't think you were actually suggesting that heat loss from having a fireplace sitting there doing nothing is significant enough to motivate someone to get rid of a fireplace. Sure, a damper is not air tight. Neither is a house door, but most people want a door. Some people want a fireplace. I'd also stick a wool plug in the flue when not using it.

Yes, the two opinions have been expressed.

The fact of whether the OP's fireplace causes a NET loss of heat from his home and actively cools the home has not been measured.

Every fireplace sends air out of the house, and more so than pretty much every wood stove. However, it certainly is not the case that every fireplace actively cools the house more than the heat it generates, resulting in a NET loss of heat. If there is data to refute this, I would be interested in it, but it seems to be a phrase that is simply repeated without basis.

To be fair, you did not say there was a "net" loss of heat... just an "active" cooling of the home, which I suppose is technically correct. But by that rationale, every wood stove also "actively cools" a house. Though it obviously heats a lot more than it cools.

I have already acknowledged that stoves are obviously more efficient... and that they are better in every single parameter, except for one, which is the experience of an open fire. I do not advocate for a fireplace instead of a stove, or even to build new fireplaces in general. I just think it can be pleasant to keep a well built fireplace that is already there in addition to a stove.

However, this acknowledgement will never be enough for many on this forum. One must denounce the Satan that takes the form of an open fireplace.


I fully agree you would be the authority on the pricing of such jobs. But we should also not overestimate the credibility of this dude that needs "scaffolding and at least 4 men" to do what you said you would prefer to do alone... and with a reasonable explanation of your process.

You said the insert wont easily fit in a rumford (correct) and the advice on the stove and liner is certainly appropriate. It would be an especially good idea if the fireplace and chimney were junk. It is STILL a good idea if the OP doesn't want to use the fireplace.

I guess my point is there are costs already invested in the nice fireplace and chimney.
For me, the options ranked from worst to best are:

1) Fireplace
2) Stove
3) Fireplace AND separate stove

But the OP will decide what is best for them. The stove will work fine with either option, and it mostly comes down to the esthetics and setup, the cost differential, and if he wants to keep the fireplace or not.

Thank you for the thoughtful advice. My personal observations after running Rumsford for 12 years is that it is not a net negative, and it is also not an effective heating tool for a large space. One day this week when had temps in the teens and high winds, my first floor was calling for 71, and temp was steady on 69 degrees. This is very rare when the HP cannot get to temperature. I got the rumsford going, and it was enough to help the HP get the space up to temperature. That being said, no matter how hard I run the rumsford in the winter, I can't get the first floor above 71. In the should months, I can raise the temperature to 74 if I run it hard.

The throat of the rumsford is very narrow, less than 4" wide. The installer wanted no part of breaking out the throat or dealing with the blue stone, he said I would have to get someone else to do it. When I spoke to the mason who built it, he stated that the throat is structural and he does not recommend breaking it out, even if it is just a partial removal to accommodate the liner. So, even if I could easily remove the bluestone as it has been suggested, the throat is the bigger problem. I have attached a picture of the throat. If I could find someone willing to put the insert in, the damage to the FP would be irreversible. Also, there is a significant offset on the chimney, which the installer mentioned could present a problem for the liner. He was talking about installing a 6" flexible, non-insulated liner, which I understand is also not ideal.

As I stated in my original post, my wife loves the rumsford, and today was no exception. Although she was originally hell bent against on a stove in addition to the rumsford, she is coming around on the idea of installing a separate stove somewhere else in the room. It is a pretty big room, so I think we can pull it off. I think this is the direction we are headed. We just need to figure out the best location for the device, and how to route the chimney pipe. The area above this room is an elevated deck with a rubber roof below it, so we are hoping we can send the pipe out the side of the house, then up. Lots of hurdles on this one, but I am determined to figure it out.

Thanks again for all the helpful advice, I really appreciate it. I will keep you guys in the loop as we progress (hopefully).

 

[bholler]

Thank you for the thoughtful advice. My personal observations after running Rumsford for 12 years is that it is not a net negative, and it is also not an effective heating tool for a large space. One day this week when had temps in the teens and high winds, my first floor was calling for 71, and temp was steady on 69 degrees. This is very rare when the HP cannot get to temperature. I got the rumsford going, and it was enough to help the HP get the space up to temperature. That being said, no matter how hard I run the rumsford in the winter, I can't get the first floor above 71. In the should months, I can raise the temperature to 74 if I run it hard.

The throat of the rumsford is very narrow, less than 4" wide. The installer wanted no part of breaking out the throat or dealing with the blue stone, he said I would have to get someone else to do it. When I spoke to the mason who built it, he stated that the throat is structural and he does not recommend breaking it out, even if it is just a partial removal to accommodate the liner. So, even if I could easily remove the bluestone as it has been suggested, the throat is the bigger problem. I have attached a picture of the throat. If I could find someone willing to put the insert in, the damage to the FP would be irreversible. Also, there is a significant offset on the chimney, which the installer mentioned could present a problem for the liner. He was talking about installing a 6" flexible, non-insulated liner, which I understand is also not ideal.

As I stated in my original post, my wife loves the rumsford, and today was no exception. Although she was originally hell bent against on a stove in addition to the rumsford, she is coming around on the idea of installing a separate stove somewhere else in the room. It is a pretty big room, so I think we can pull it off. I think this is the direction we are headed. We just need to figure out the best location for the device, and how to route the chimney pipe. The area above this room is an elevated deck with a rubber roof below it, so we are hoping we can send the pipe out the side of the house, then up. Lots of hurdles on this one, but I am determined to figure it out.

Thanks again for all the helpful advice, I really appreciate it. I will keep you guys in the loop as we progress (hopefully).

View attachment 290495

Ahh it's a prefab rumford. That changes things. You cannot open up the throat of them.

 

[N.E.K. - D.D.S.]

I am open minded and will look into this.
Thank you for sending the reference.

Have you read this? There is some difficult statistical analysis.

This study looks at the total energy that houses are using - including for heating and for everything else. Some of the houses have only electricity while some have electricity and gas. They measure (from utility bills) the total amount of electricity and gas used during the months of December, January, February (the heating season in San Antonio, Texas where this study takes place).

They account for several factors like the size of the home, age of the home, presence of a swimming pool or spa (which would use more electricity), etc. and also for the temperature from weather reports. After adjusting for those factors, they can calculate that on average, during the 3 month heating season in San Antonio Texas, homes with fireplaces used more total energy (in the form of electricity and gas) than homes without fireplaces by 31%.

This is consistent with the idea that fireplaces are inefficient devices (although none of us dispute that). The study shows that fireplaces can be a "significant energy user" and it focuses on limiting total energy consumption by the rapidly growing city.

This study does NOT show that fireplaces cause a net loss of heat (that they suck out more heat than they generate).
This study certainly does not imply that any significant losses are the result of chimneys sitting there not in use.

It does however seem you have some support from Bholler:

The vast majority of fireplaces take more heat out of the house when burning than they add. A well designed Rumford may not but that is a big if.

This is a very balanced and careful statement! Including "majority" (rather than all) and "while burning" make it much more palatable.... though it is still surprising.

I am going to try to find some actual data on this. If anybody has it, let me know. The inefficiency is pretty well documented, but this "net loss" idea.... I have not yet seen it.

 

[N.E.K. - D.D.S.]

My personal observations after running Rumsford for 12 years is that it is not a net negative, and it is also not an effective heating tool for a large space.

This has been my experience with my Rumford also.

The installer wanted no part of breaking out the throat or dealing with the blue stone, he said I would have to get someone else to do it.

See, these guys have no professional or ethical obligation do what a customer needs. Some of them just cherry pick the easy jobs that they want and say no to the others. That being said, there are some honourable ones.

I bet that Bholler would at least present you your options and risks, make you sign a waiver, and give you some sort of price on it if you said you absolutely wanted something done a certain way (while of course recommending what he feels is the best way). This is how things should be.

But of course it could have been a lot worse. They could have broken the fireplace, put in an uninsulated liner, charged you a bunch of money, and left you with a poorly drafting stove and your wife without a fireplace.

There is a significant offset on the chimney, which the installer mentioned could present a problem for the liner. He was talking about installing a 6" flexible, non-insulated liner, which I understand is also not ideal.

You are correct. Now this is a reason that the pros (admittedly more experienced and knowledgeable regarding design than I) will not disagree with me on. The two different installs are no longer equivalent. Both can be made to "work" but for sure they will prefer a straight pipe with insulation to an offset pipe without insulation.

As I stated in my original post, my wife loves the rumsford, and today was no exception. Although she was originally hell bent against on a stove in addition to the rumsford, she is coming around on the idea of installing a separate stove somewhere else in the room.

Great! Try to think of a way to bribe her. I am trying to come up with a way to bribe or otherwise coerce my wife into going INSIDE our huge chimney to clean it, as her body is smaller than mine.

We just need to figure out the best location for the device, and how to route the chimney pipe. The area above this room is an elevated deck with a rubber roof below it, so we are hoping we can send the pipe out the side of the house, then up.

It is certainly possible to go out the side wall and up, and has been done many times, but if you can go straight up it is going to be the absolute best (especially if chimney is short and especially if it is not too cold). Would it be really intrusive to have a stainless steel pipe up through the deck? The people here can certainly help you with that better than I can, so best I am not too involved.

Thank the sweet Lord that you responded when you did. Many of our arguing points on this thread are now irrelevant with the new information.

That fireplace is not historic, but it is nice. I am happy you did not ruin it! Haha. I can sleep tonight.

 

[bholler]

bet that Bholler would at least present you your options and risks, make you sign a waiver, and give you some sort of price on it if you said you absolutely wanted something done a certain way (while of course recommending what he feels is the best way). This is how things should be.

Nope I will without hesitation refuse to do something that I think is wrong. I would refuse to cut into that throat as well. And I honestly don't think a liner ovalized to that dimension would function properly. I would most likely not consider lining that fireplace for a stove or insert.

 

[N.E.K. - D.D.S.]

Nope I will without hesitation refuse to do something that I think is wrong. I would refuse to cut into that throat as well. And I honestly don't think a liner ovalized to that dimension would function properly. I would most likely not consider lining that fireplace for a stove or insert.

Hmm.
But you would give him SOME kind of option, right?

 

[bholler]

Hmm.
But you would give him SOME kind of option, right?

Well yes I would tell him because of the nature of his prefab fireplace a liner for a stove or insert isn't an option. If he wants a stove it needs to have a separate chimney.

 

[stoveliker]

Have you read this? There is some difficult statistical analysis.

This study looks at the total energy that houses are using - including for heating and for everything else. Some of the houses have only electricity while some have electricity and gas. They measure (from utility bills) the total amount of electricity and gas used during the months of December, January, February (the heating season in San Antonio, Texas where this study takes place).

They account for several factors like the size of the home, age of the home, presence of a swimming pool or spa (which would use more electricity), etc. and also for the temperature from weather reports. After adjusting for those factors, they can calculate that on average, during the 3 month heating season in San Antonio Texas, homes with fireplaces used more total energy (in the form of electricity and gas) than homes without fireplaces by 31%.

This is consistent with the idea that fireplaces are inefficient devices (although none of us dispute that). The study shows that fireplaces can be a "significant energy user" and it focuses on limiting total energy consumption by the rapidly growing city.

This study does NOT show that fireplaces cause a net loss of heat (that they suck out more heat than they generate).
This study certainly does not imply that any significant losses are the result of chimneys sitting there not in use.

It does however seem you have some support from Bholler:


This is a very balanced and careful statement! Including "majority" (rather than all) and "while burning" make it much more palatable.... though it is still surprising.

I am going to try to find some actual data on this. If anybody has it, let me know. The inefficiency is pretty well documented, but this "net loss" idea.... I have not yet seen it.

I have read it yes. (And I read scientific - physics- articles for a living...)
Either they simply measure the heating energy consumption and note thay homes with fireplaces use more/less, or they correct for correlations that influence the bare number. The latter is now criticized by you.

The fact of the matter is that homes with fireplaces use more energy - after all corrections are analyzed. (And I note this is standard stuff: the same happens in medical studies where one has to correct for e.g. overweight or smoking people in risk statistics.)

They don't explain why that is. But the glaring heat waste is the hole in the house sucking up heated air, whether the fireplace is used or not.

 

[N.E.K. - D.D.S.]

I have read it yes. (And I read scientific - physics- articles for a living...)
Either they simply measure the heating energy consumption and note thay homes with fireplaces use more/less, or they correct for correlations that influence the bare number. The latter is now criticized by you.

The fact of the matter is that homes with fireplaces use more energy - after all corrections are analyzed. (And I note this is standard stuff: the same happens in medical studies where one has to correct for e.g. overweight or smoking people in risk statistics.)

They don't explain why that is. But the glaring heat waste is the hole in the house sucking up heated air, whether the fireplace is used or not.

Well, of all the disciplines Physics is probably THE most intellectually demanding, so I certainly acknowledge that. I also respect that you are even having the discussion with me.

It is not the most sophisticated methodology used in this study, but yes I agree that they are able to demonstrate what they call a "fireplace effect" where homes with fireplaces use more total energy than homes without. They say this is to be a springboard for further investigation to quantify the effects more specifically. We agree that there is a significant effect. My issue is that your conclusions are not supported (or even addressed) by this study.

It just struck me that maybe a big part of our disagreement could be in the way we are defining things. If you mean that using a fireplace is a "net loss" to the HOME as far as cost/consumption when running concurrently with another heating source... well then yes, it seems that would be true. This speaks to the inefficiency of the fireplace. (which we also agree on). It just means that it costs less energy to generate a given amount of heat in a home with pretty much ANYTHING other than a fireplace... like a furnace, boiler, or a wood stove. I can agree there.

However, if you are saying that there is a "net loss" with a fireplace itself, independently, as if running it on its own makes a space colder than NOT running it... then no way. People with well designed and well built antique Rumford fireplaces will report that this is not the case. The efficiency rating may be low, but it is not a negative number.

If a net loss happens with a lot of poorly designed modern fireplaces (as you and Bholler and others have suggested), then that is quite interesting.... I just want to find some data on it (if it is indeed true), because that is not addressed by this particular article.

This study IS interesting and even surprising, and I appreciate you sending it. But also remember that most of the households in that Texas study are burning gas in their fireplaces (with a few burning wood or electric). I AM curious (as you are) about how much heat is going out the chimney. ***But a huge part of the increased energy usage is simply that they are burning gas in a fireplace (inefficiently) rather than gas in a furnace (efficiently)***. I took that to be more the point of the article.

As for this increased energy consumption being due to the presence of a chimney "whether the fireplace is used or not".... that is not a conclusion made by this study. It is also not a correct assumption.

I will agree that the presence of a chimney (or a door or a window) is obviously always going to cause some amount of loss (and should be mitigated to the extent possible with a wool plug or similar damper). You know as well as I do that the simple presence of a chimney not in use is NOT causing a significant portion of the 31% increased energy use. That is clearly not a conclusion that can be made from this data.

That being saisd, I do think we are gradually coming closer to a consensus rather than farther apart.

 

[bholler]

Well, of all the disciplines Physics is probably THE most intellectually demanding, so I certainly acknowledge that. I also respect that you are even having the discussion with me.

It is not the most sophisticated methodology used in this study, but yes I agree that they are able to demonstrate what they call a "fireplace effect" where homes with fireplaces use more total energy than homes without. They say this is to be a springboard for further investigation to quantify the effects more specifically. We agree that there is a significant effect. My issue is that your conclusions are not supported (or even addressed) by this study.

It just struck me that maybe a big part of our disagreement could be in the way we are defining things. If you mean that using a fireplace is a "net loss" to the HOME as far as cost/consumption when running concurrently with another heating source... well then yes, it seems that would be true. This speaks to the inefficiency of the fireplace. (which we also agree on). It just means that it costs less energy to generate a given amount of heat in a home with pretty much ANYTHING other than a fireplace... like a furnace, boiler, or a wood stove. I can agree there.

However, if you are saying that there is a "net loss" with a fireplace itself, independently, as if running it on its own makes a space colder than NOT running it... then no way. People with well designed and well built antique Rumford fireplaces will report that this is not the case. The efficiency rating may be low, but it is not a negative number.

If a net loss happens with a lot of poorly designed modern fireplaces (as you and Bholler and others have suggested), then that is quite interesting.... I just want to find some data on it (if it is indeed true), because that is not addressed by this particular article.

This study IS interesting and even surprising, and I appreciate you sending it. But also remember that most of the households in that Texas study are burning gas in their fireplaces (with a few burning wood or electric). I AM curious (as you are) about how much heat is going out the chimney. ***But a huge part of the increased energy usage is simply that they are burning gas in a fireplace (inefficiently) rather than gas in a furnace (efficiently)***. I took that to be more the point of the article.

As for this increased energy consumption being due to the presence of a chimney "whether the fireplace is used or not".... that is not a conclusion made by this study. It is also not a correct assumption.

I will agree that the presence of a chimney (or a door or a window) is obviously always going to cause some amount of loss (and should be mitigated to the extent possible with a wool plug or similar damper). You know as well as I do that the simple presence of a chimney not in use is NOT causing a significant portion of the 31% increased energy use. That is clearly not a conclusion that can be made from this data.

That being saisd, I do think we are gradually coming closer to a consensus rather than farther apart.

It isn't just modern fireplaces. It is very rare to find a fireplace that was designed and constructed well. Most called rumfords are still poorly executed.

Now you are correct if there was no other heat source in the house it wouldn't be a net loss because you would still get the radiant heat but wouldn't be sucking air that had already been heated by another source out of the house. The problem with that argument is that no one is really willing to do that.

 

[Caw]

It isn't just modern fireplaces. It is very rare to find a fireplace that was designed and constructed well. Most called rumfords are still poorly executed.

Now you are correct if there was no other heat source in the house it wouldn't be a net loss because you would still get the radiant heat but wouldn't be sucking air that had already been heated by another source out of the house. The problem with that argument is that no one is really willing to do that.

How efficient is a well built Rumford? I know a regular fireplace is between 1-5% or so. I did a quick Google and found this hilarious Stat that pops up first:

 

[bholler]

How efficient is a well built Rumford? I know a regular fireplace is between 1-5% or so. I did a quick Google and found this hilarious Stat that pops up first:

View attachment 290545

Rumfords are not really a completely standardized design so there isn't a set value. But it's pretty much agreed that good ones are about 8% to 10%.

Prior fire fireplaces are a bit better. They claim to get to 15%

 

[Caw]

Rumfords are not really a completely standardized design so there isn't a set value. But it's pretty much agreed that good ones are about 8% to 10%.

Prior fire fireplaces are a bit better. They claim to get to 15%

I mean those numbers are big improvements over a 1% standard fireplace but it's still wild to think about "the best" being only 15% versus a modern epa stove around 70-75%.

My mother still uses her old 1960s open fireplace every year, you'll have to pry out of her cold dead hands. It's inefficient, smokey, and smelly but she loves it. I like it on Xmas eve once a year for nostalgia but that's enough for me. I love my modern stove.

 

[stoveliker]

Thank you for the respect, but a background does not deserve or demand that. Politeness between humans does. And that should be sufficient. I hope to have shown that by not calling names, and I acknowledge you did so (too).

Next, despite the 100 pct losses being compensated by 105-110 pct of heat in a *running* fireplace, the biggest loss is during the (majority of) hours during which the fireplace does not run.
Use an incense stick near or in a fireplace with the damper closed and see where the smoke goes. That goes on 24/7. That is air from your home, on which energy was spent to heat it to 68-ish degrees that goes out the chimney.

That is the problem with fireplaces.

Again, if the aesthetics is worth it to someone, by all means, keep a fireplace. But that doesn't change the facts of the presence of a fireplace being a net energy loss to a home.

It's fine with me if you don't agree. I'll stop here as I don't see this going much farther being a fruitful discussion.

And for what it's worth, I very much appreciate you trying to keep history alive and functional in your own home. That kind of aspect can certainly change the balance into keeping a fireplace. Too much historical stuff is going down already...

 

[N.E.K. - D.D.S.]

Now you are correct if there was no other heat source in the house it wouldn't be a net loss because you would still get the radiant heat but wouldn't be sucking air that had already been heated by another source out of the house. The problem with that argument is that no one is really willing to do that.

Yes I see what you mean. People only did it back when fireplaces were the only source of heat in this house. It would be somewhat warm from radiant heat at the fireplace and cold in the more distant parts of the house.

For me personally, I do not run a fireplace in cold weather while I am cranking out serious heat with some other device.

There are these days in Spring or in Fall, when it is a bit chilly in the morning or in the evening... or maybe an entire dreary day when the actual temperature outside is not much cooler than the internal temperature. Firing up a wood furnace is too much. I could burn a little oil, but these are times that I might like to hang out by the fireplace (and only the fireplace) sort of like a campfire. An open fire in my backyard in summer is a real waste of wood too, but it is fun. These shoulder season times (or in more mild climates) are when I think it might be appreciated.

Thank you for the respect, but a background does not deserve or demand that.

It does not NECESSARILY demand it, and there are certainly many different factors which could earn my respect. But a background in something certainly doesn't make things WORSE!

I just really really like physics, and used to read a lot of it, so I related, that's all. I am always studying a million different things. It was a ton of science when I was young, but then psychology, history, music theory. I am always involved in food and cooking. In more recent times I had been studying a lot of plumbing and electrical.

People on this site have a wide range of interests and backgrounds. I find it to be a very intelligent forum overall.

Politeness between humans does. And that should be sufficient. I hope to have shown that by not calling names, and I acknowledge you did so (too).

Yes, politeness counts for something. I would not attack you for no reason. I only defend myself when necessary.

When I wrote, "I also respect that you are even having the discussion with me" what I meant was that I am happy that we can engage in some debate, and refine our understanding of some of the subtleties of these points.

You were not just spewing nonsense with no basis (as some people do).

the biggest loss is during the (majority of) hours during which the fireplace does not run.
Use an incense stick near or in a fireplace with the damper closed and see where the smoke goes. That goes on 24/7. That is air from your home, on which energy was spent to heat it to 68-ish degrees that goes out the chimney.

That is the problem with fireplaces.

My fireplaces are so old they don't even have a damper. They are stuffed with insulation. I am not aware of just how leaky a typical fireplace damper is, but I see what you mean. It is the like leaky doors, windows, etc.

Again, if the aesthetics is worth it to someone, by all means, keep a fireplace. But that doesn't change the facts of the presence of a fireplace being a net energy loss to a home.

See, each of us has made more nuanced and accurate statements... and now there is much more of an agreement.

I see what you mean, and to determine if it is worth having a fireplace at all (sitting unused), we need to know just how much passive heat loss there is. I assumed it was small, but I don't know the numbers. The study quoted (while useful in concept) does not quantify this. There has to be some info on this for doors, windows, chimneys, etc. etc.

It is the same as having a cathedral ceiling.... or a huge window. They are not good from an efficiency standpoint, but maybe they are cool things to have. One can calculate the cost of having it. Now we are getting somewhere.

It's fine with me if you don't agree. I'll stop here as I don't see this going much farther being a fruitful discussion.

Oh, it has been fruitful!!

And for what it's worth, I very much appreciate you trying to keep history alive and functional in your own home. That kind of aspect can certainly change the balance into keeping a fireplace. Too much historical stuff is going down already...

Thanks, Yeah, I wouldn't build a new fireplace. But there are four of them here.
One has no chimney above the roof anymore, so it is toast.
Two have wood stoves in them, an I have tried to select models and sizes that maintain the visual of the original fireplace.

The last fireplace... I am quite torn between keeping it an open fireplace or with a pretty antique stove in it (also inefficient but not quite as bad as an open fire obviously). It is in the dining room... and used only very occasionally for ambiance, and radiant heat while at the table. It is not for any kind of serious heating.

 

[Drewby]

How efficient is a well built Rumford? I know a regular fireplace is between 1-5% or so. I did a quick Google and found this hilarious Stat that pops up first:

A well built rumford is much much better than people give them credit for. Jim Buckley claims around 50% with some of his models and he’s not too far off IMO. I know for a fact that mine will keep a large house mostly in the mid 60’s when is 15 degrees outside. This was tested by me over a 7 day period running it for about 18-20 hours a day with all other heat turned off. I just wanted to see what it would do if the power was out. The back bedrooms were probably in the 50’s and the the great room and upstairs were 70+ degrees. I burned around 20-25 lbs of wood an hour and recovered around 40% of that heat. My unit is 60” and is not as efficient as a 36” fireplace. I should probably be burning closer to 30-40 lbs and hour but that’s too much heat. I would receive about 60k btu’s from this (20-25lbs and hour) and that includes heating the makeup air. At full throttle this could easily put 100k into the house an hour.

I’m not sure where people that have never used a real one claim that they offer little heat, I assure you it will heat a wall surface to over 80 degrees that is 50’ away. It will heat a large wall surface that is 30’ away to well over 90 degrees. When it’s all warmed up you need to be 10’ away if your directly in front and even that’s pretty warm.

With all that being said it is truly the most awesome thing in my house and I would have another in any house I own.

 

[bholler]

A well built rumford is much much better than people give them credit for. Jim Buckley claims around 50% with some of his models and he’s not too far off IMO. I know for a fact that mine will keep a large house mostly in the mid 60’s when is 15 degrees outside. This was tested by me over a 7 day period running it for about 18-20 hours a day with all other heat turned off. I just wanted to see what it would do if the power was out. The back bedrooms were probably in the 50’s and the the great room and upstairs were 70+ degrees. I burned around 20-25 lbs of wood an hour and recovered around 40% of that heat. My unit is 60” and is not as efficient as a 36” fireplace. I should probably be burning closer to 30-40 lbs and hour but that’s too much heat. I would receive about 60k btu’s from this (20-25lbs and hour) and that includes heating the makeup air. At full throttle this could easily put 100k into the house an hour.

I’m not sure where people that have never used a real one claim that they offer little heat, I assure you it will heat a wall surface to over 80 degrees that is 50’ away. It will heat a large wall surface that is 30’ away to well over 90 degrees. When it’s all warmed up you need to be 10’ away if your directly in front and even that’s pretty warm.

With all that being said it is truly the most awesome thing in my house and I would have another in any house I own.

I am sorry but Jim Buckley is full of sht. A very nice guy but I have attended 2 of his lectures and he makes lots of wild claims but refuses to answer questions about how he came upon the numbers.

 

[Drewby]

I am sorry but Jim Buckley is full of sht. A very nice guy but I have attended 2 of his lectures and he makes lots of wild claims but refuses to answer questions about how he came upon the numbers.

I came up with similar numbers but not quite as high. Mine were based off of the heat load calcs of my house. It needed something like 60kbtus for a 50 degree heat rise and this unit provided it. The wood used was around 20-25 lbs and hour. It was at a medium burn rate. Would of been better suited to a 48” or even a 42” unit as they use much less air. Anybody who claims that they (a Buckley rumford fireplace) are a net heat loser is a man that speaks on a topic that he knows nothing about. Anybody who says they are 10% effiecent is around 400% off on his assumption.

 

[bholler]

I came up with similar numbers but not quite as high. Mine were based off of the heat load calcs of my house. It needed something like 60kbtus for a 50 degree heat rise and this unit provided it. The wood used was around 20-25 lbs and hour. It was at a medium burn rate. Would of been better suited to a 48” or even a 42” unit as they use much less air. Anybody who claims that they (a Buckley rumford fireplace) are a net heat loser is a man that speaks on a topic that he knows nothing about. Anybody who says they are 10% effiecent is around 400% off on his assumption.

A well built Rumford will absolutely not be a net loss but there is absolutely no way it will ever get to 50%. Btw I am not basing my numbers upon assumptions. There has been lots of actual testing done on this subject. I will try to locate some of the studies.

 

[bholler]

By the way Chris Prior used to make similar claims. Then he had some of his fireplaces actually tested when they started to develop the new prefab and the actual numbers were nowhere near his claims

 

[stoveliker]

A well built rumford is much much better than people give them credit for. Jim Buckley claims around 50% with some of his models and he’s not too far off IMO. I know for a fact that mine will keep a large house mostly in the mid 60’s when is 15 degrees outside. This was tested by me over a 7 day period running it for about 18-20 hours a day with all other heat turned off. I just wanted to see what it would do if the power was out. The back bedrooms were probably in the 50’s and the the great room and upstairs were 70+ degrees. I burned around 20-25 lbs of wood an hour and recovered around 40% of that heat. My unit is 60” and is not as efficient as a 36” fireplace. I should probably be burning closer to 30-40 lbs and hour but that’s too much heat. I would receive about 60k btu’s from this (20-25lbs and hour) and that includes heating the makeup air. At full throttle this could easily put 100k into the house an hour.

I’m not sure where people that have never used a real one claim that they offer little heat, I assure you it will heat a wall surface to over 80 degrees that is 50’ away. It will heat a large wall surface that is 30’ away to well over 90 degrees. When it’s all warmed up you need to be 10’ away if your directly in front and even that’s pretty warm.

With all that being said it is truly the most awesome thing in my house and I would have another in any house I own.

The crucial part you didn't mention being "while it runs", because fireplaces (especially when consuming a godawful amount of wood measured in 10s of lbs per hours ..) tend to run only a small fraction of a day, while contributing to the loss side of the equation 24/7/365.

Any person claiming heating efficiency while disregarding this obvious fact has not looked at the whole picture.

Again, I'm attracted to fire. I get it. But that doesn't make facts go away.