# Do fireplaces have vents?



## joecaption (Nov 30, 2011)

It's a heatolater.
Cold air gets sucked in at the bottom, it gets heated and warm air comes out the top.


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## picflight (Aug 25, 2011)

I have not seen vents in fireplace, but it could be to aid in the draft perhaps.

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## notmrjohn (Aug 20, 2012)

" a chamber that leads somewhere." You stay here and I'll go see where it goes. Guess which one of us dies in the next scene after I go off doing the dangerous part.
I gotta edit joe's answer, if he'll allow me. How's he gonna stop me? he won't even see me asking permission until I've already done it.
Cold air,_which Floridians import by insulated tanker ship from Alaska_, gets sucked in at the bottom, it gets heated and warm air comes out the top, _where it is collected and shipped back so Alaskans can run their air conditioners._
heatolater i bet that name is not as old as the concept. Probably pre-Roman at least. I've seen andiron like gizmos that attempt to do similar job, pipes under logs open end towards room,, bent up back and over logs, open back towards room. Air goes in bottom, heated air out top. Fire places barely more efficient than open fires, safer in living room though.


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## joecaption (Nov 30, 2011)

I just figured the O/P did not want to be burdened with all the fine details so I left that info out. Thanks for filling in the blanks.

Trying to use an open fire place like that for heat makes as much since as and works as well as leaving a door wide open. The best part is you loose heat and A/C out of it all year long cost you money.

Where does it get it's make up air, by sucking in the air from other rooms. What happens when you have a negative pressure in a home and it's cold outside, it sucks it into the house through every crack it can find and spits it out the chimmney as unused BTU's.


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## notmrjohn (Aug 20, 2012)

sucking cold air into house and spitting warm air out chimney...Thankfully modern technology has solved those problems . Sucking cold air into house? Install vent from outside to fire place! warm air from house still goes up chimney. Install glass over fire place! Heats glass up, glass warms anything within 2 inches but can't hear crackling fire. Buy recording of crackling fire. Smoke and pitch all over glass, can't see fire. Get video of fireplace. Miss that aroma of apple wood, pecan, even pinon pine? Burn incense. Incense sure makes it smoky in here we need to put in some kind of thing that would get smoke out.
Technology even improved that pipe andiron. First one I saw was at a friends, didn't help much. Next time I was over there he'd replaced it with one that had a fan, had a box type thing in back instead of pipes. Next time I visited, chimney flue closed, electric radiant heater in fire place.
Say, wheres miamicuse? He was right here when I went to see where that chamber lead. You wait here, I'll go see if I can find him.


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## weekendwarrior9 (Sep 10, 2012)

That's why we have a cast iron stove in our fireplace. The beast heats the whole room up and then some, with a bare minimum of smoke.

Hard to beat the price of a couple pieces of wood to heat most the house up on a cold night.


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## jomama45 (Nov 13, 2008)

As has been metioned, the vents draw room air across and over the unit, and emit worm air out of the top. Most work through convection, but there is also an option for small fans to be installed in the bottom vents. Contrary to "popular belief", they actually do heat fairly decent when burning. It's true that they can allow a large amount of warm air out of the residence when not burning, and they also serve as a "cold sink" due to the expansive amount of masonry exposed to the exterior.

THat being said, I know a few folks that have them and are pleased with them. My neighbor is actually a mason as well, and 80-90% of his heating is done with a 42" see-thru masonry inset. He even has 2 vents trunked off to adjacent rooms......

http://yourwayfireplaces.com/docs/VestalAire Circulator Fireplace.pdf


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## notmrjohn (Aug 20, 2012)

warrior, Ben Franklin had a lot of good ideas, that stove was one of his great ones. In ol' timey days pot belly and other stoves were right out in the middle of the room so folks could sit all around it. Many of the worlds problems, ( war, poverty, drought, inflation, recession, etc are a thing of the past thanks to geniuses gathered 'round down at the general store. Often the stove pipe does not go straight up, but across the room below the ceiling, sometimes thru wall into other room, to try to use some of the heat passing thru. Took some knowledge to get right length and slope, to prevent back drafts and so gases didn't cool too much to rise and draw. Luckily geniusses were at hand, so only occaisional room filling belch of smoke. Cartoonists always draw top of stove pipe with a double ell, even if it has a rain?wind cap, ells were to "prevent" wind from blowing down giving stove an upset pot belly.
*jo*, its not just "popular belief," lots of tests done by nerdy unpopular engineers have shown that open hearth fire place is barely barely better than open fire under hole in roof. Some designs actually rob _entire house_ of more heat when burning than when not. Though immediate area may be warmer due to radiant heat. If by " see-thru masonry insert" you mean that glass fronted, outside draw hearth that i laughed at, when combined with heatolaters ( gotta love that word), ducts, vents, scary chambers, conducters, convecters, radiaters, etc. in fireplace and chimney, it is an improvement and, as you say, do fairly decent job, emphasis on fairly.
A big chunk of masonry is a cold sink, actually a heat sink but you knew that since you used quotes.( them nerdy engineers say there's no such thing as cold.) But once heated that chunk is a heat battery and becomes a heat emitter. One reason fire places in old castles are so huge and massive, bigger batery. And there's the Dutch stove, big block of masonry covered in decorative tile; the shepeard's bed of US Southwest, via Spain, big wide and long topped adobe inefficient open hearth fireplace. Build a fire, heat up 'dobe, sleep on top. 
The direct connection between interior and exterior masonry is a a great conductor of heat to outside,, trying to "heat the entire neighborhood." Lots of ingenious attempts to aleviate that. like stone fireplace with wattle and mud chimney, POOF!. Over at the castle they tried a short chimney, poking up and free standing inside a bigger chimney coming down just enough to cover it. The whole thing inside a room of its own, cause they leaked. Before the age of enlightenment and Ben Franklin and the rise of unpopular engineers to see those rooms, historians thought they were inside smoke houses or even execution chambers where out of favor wives or overly presumptive heirs could be asphyxiated and preserved in one step. Later on they ran isolated flues inside isolated chimneys, which, while not preventing regicide, is how lots are done today.
But any system that openly burns fuel without outside draft and some sort of heat exchanger is inherently inefficient. the Romans knew that and invented central heating, heated swimming pools and radiant floor heating. They had to do that floor thing since they weren't fairly decent, rolling around on cold floors put a crimp in their fairly indecent orgie activities. Guess you could say them Romans was hot stuff.
Anybody seen joe? Wait here I'll go see if I can find him.


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## jomama45 (Nov 13, 2008)

As a masonry contractor who's done his fair share of research and installation of numerous natural masonry fireplaces in high end homes, I'm not even going to bother with a response to your attempt at a pre-face to a novel. I gave the OP what they where asking for and an illustration of how it works. I have no interest in discussing "nerdy engineer's" theories................


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## notmrjohn (Aug 20, 2012)

Jeeze, sorry, jomama. I didn't know I had to get pre-approval of content to post. 

" I'm not even going to bother with a response to your attempt at a pre-face to a novel." then why did you? " gave the OP what they where asking for and an illustration of how it works, " that had already been done, but so what. Nothing wrong with repeating it, its done all the time here. It is a "popular belief" that open fire places are an inefficient home heating system, OK, fairly inefficient, which is a synonymn for fairly decent, depending on what you're comparing to.. The belief just happens to be backed up by research, but what do engineers know, with there fancy thermometers and air flow meters and charts and all. I bet none of them have ever built a fire place for a rich man.
There is an ignore feature here, if my novels disturb you so much, use it.


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## jlmran (Feb 8, 2010)

My fireplace vents are tied into the return duct system, so it supplements the forced air heat throughout the rest of the house.


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## notmrjohn (Aug 20, 2012)

jim, it seems like you' d lose the benefit of the heated air from the "heatolater" when the central unit wasn't running. Some arrangement or other get around that?


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## jlmran (Feb 8, 2010)

notmrjohn said:


> jim, it seems like you' d lose the benefit of the heated air from the "heatolater" when the central unit wasn't running. Some arrangement or other get around that?


If the central unit isn't running, that means the thermostat is communicating that it's warm enough in the house. Seems logical to me. ???


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## jomama45 (Nov 13, 2008)

notmrjohn said:


> Jeeze, sorry, jomama. I didn't know I had to get pre-approval of content to post.
> 
> " I'm not even going to bother with a response to your attempt at a pre-face to a novel." then why did you? " gave the OP what they where asking for and an illustration of how it works, " that had already been done, but so what. Nothing wrong with repeating it, its done all the time here. It is a "popular belief" that open fire places are an inefficient home heating system, OK, fairly inefficient, which is a synonymn for fairly decent, depending on what you're comparing to.. The belief just happens to be backed up by research, but what do engineers know, with there fancy thermometers and *air flow meters* and charts and all. I bet none of them have ever built a fire place for a rich man.
> There is an ignore feature here, if my novels disturb you so much, use it.



And there-in lies the real problem. They often mistaking mistreat open fireplaces as a conventional heating appliance like a forced air furnace, wood stove, etc.... when testing. Although a unit like the OP's gives off convective heat, it's not it's sole heating purpose, merely an added benefit. When you test a product on how it performs in every category other than what it excells at, your bound to get erronious results. From what I recall from research in the past, theres 8-10 different accepted approached for rating efficiencies of wood fired heat sources. Picking & choosing the optimal results that best suits your objective is something that happens on a regular basis..........


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## notmrjohn (Aug 20, 2012)

Jo, I have only said that a fire place is an inefficient means of heating. They were inefficient when they were highest state of the art in heating they are inefficient now. I do not understand what your point is. You can add all sorts of improvements, they are still inefficient. The fact that are so many add on "improvements"; some work to a certain extent, some are worthless money making gadgets; just underscores the point. I'll repeat it is not only a "popular belief" it is a proven fact.

What other puprpose, heating or other, does miami's unit serve? (Hmmm, the heatilater I mean, besides being a sppoky chamber that leads somewhere?)

I can only think of four categories that a fire place can be tested in; heating, cooking, aesthetics, and as a means of entry and egress for a right jolly old elf. It does not excel at heating and cooking, its certainly more aesthetically pleasing than an oil burning furnace, and the blower in a central unit is likely to make Santa fillets. A fire place can be used to burn old love letters or evidence, but from what I see on Tv and read in _novels_ somebody sherlock always figures a way to read them, so it does not excell at that. When we test something we should be testing it for the purpose for which we will be using it. What is the point in testing something in everything but what it excells at? Besides we are not testing the fire place in what it excells at, but what, in comparison, it fails at. 

There is only one category to test any heat source as a heat source, "How well does it produce heat?" Every thing else is a consideration and/or comparison , fuel costs, cleanliness, ease of operation and maintenance, distribution of heat, etc. An _*air flow meter *_ is just one tool used in some tests. In conjunction with a thermometer it can tell if more heat is coming in from or going out through the fire place. 

Here's what the EPA says ",...a fireplace is an inefficient way of heating your home. Fireplaces provide less heat..., since most of the heat goes out the chimney...a fireplace tends to suck all the warm air in a home... up the chimney. ... expect other rooms... to be cooler due to escaping warm air. If using central heat while burning in a fireplace, expect your heater to work harder to maintain temperatures throughout the house."

The Masonry Advisory Council, with which you may be familiar, says, "air that fuels a fire...( Ok, they're masons not nerdy engineers. _nmj_) ... has to come from somewhere. the air drawn into the firebox comes from the house and has already been heated by the central heating system. As the air is expelled up the flue, it has to be replaced by more air. (Replacement air) must infiltrate the house from the outside, be heated up by the central heating, and then fuel the fire." Air as fuel what will they think of next? There's also a nifty chart, drawn up by unpopular engineers who had nothing better to do on Saturday nights. http://www.maconline.org/tech/design/fireplace1/efireplace/efireplace.html
*miami*, You'll be glad to see that ypur frigid 40 degree winters are just above the break even point for an open face fire place, produces just a tad more heat than it loses. With that heatilater, I bet you can get down to ohhh 38 or so.
*jim*, my lad, if you put the fire out when the central isn't running you'll be even more efficient. The pupose of the "vents" is to add some heat to room so central doesn't come on so often.If you had powerful enuff fans on the vents and tied into central ducts you might get some results. But then you'd just have an inefficient wood burning central heat system. Inefficient even for wood burning and as a central system . However, your vents might be giving a slight prewarming to that infiltrating cold air your central unit is drawing in to replace the centrally heated air the fire place is sending up the chimney. 

I'm going into jim's ducts to check it out, you wait here. Say, what happened to the warrior?


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## jlmran (Feb 8, 2010)

notmrjohn said:


> jim, my lad, if you put the fire out when the central isn't running you'll be even more efficient. The pupose of the "vents" is to add some heat to room so central doesn't come on so often.If you had powerful enuff fans on the vents and tied into central ducts you might get some results. But then you'd just have an inefficient wood burning central heat system. Inefficient even for wood burning and as a central system . However, your vents might be giving a slight prewarming to that infiltrating cold air your central unit is drawing in to replace the centrally heated air the fire place is sending up the chimney.


1. My name isn't Jim. Read more carefully.
2. I'm not your lad. I am my father's lad.
3. You assume too much. Why do you assume the central unit is drawing in cold air?


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## Tscarborough (Mar 31, 2006)

Heatolater and Queenair fireboxes are both very effective methods of heating, especially when using forced air (fans) and outside air kits. Rumford fireplaces are also very effective. The added ambiance is a bonus.


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## notmrjohn (Aug 20, 2012)

*jL*m,
1. Sorry, these old eyes ain't what they used to be, never was very good, glasses, thick glasses, since third grade. They really strain at a computer screen.


2. I apologize for the over familiarity and presumption on your good nature. 'Twas but a quotation from a _novel_ by Robert Lewis Stevenson no longer apropos as your name don't be jim.



3. See the above thread. So far no one has disputed the EPA's or MAC's findings concerning fireplaces and central heating systems. But, you are right, I did assume too much, basing my assumption on the information I had concerning your vent arrangement. I assumed any air infiltration in the heating season would be cold. Perhaps you have a thoroughly sealed air tight home preventing any air infiltration at all, warm or cool, In which case, I assume, with trepidation, that you have carbon monoxide alarms and back draft protection in your fire place.


Mayhap, you have one of *T*'s, (If I maybe so bold as to so yclept *you* so familiarly, and assuming you didn't get disintegrated in the latest campus non-bomb explosion, or lanced by the feared Cyclotronic Knight, while protecting the Queen, Heir to Waxahachie) But I digress. Mayhap, jlm you have a *Queenair* system, Remarkably similar to the idea I had, (how do they steal my inventions B4 I even think of them?) but using a 500CFM fan and bypassing the central air handler completely.. jlm, if you are satisfied with your system, I have no quibble with you, if you seek no refinement nor improvements, I shall not presume to make suggestions. Nor observations.


Instead I shall sit upon the hearth rushes
And tell sad stories of the death of kings;


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## jomama45 (Nov 13, 2008)

Just the tip of the iceburg when it comes down to the inaccuracies of rating wood-fueled heating appliances.......................

http://www.omni-test.com/publications/Efficiency_Eye.pdf


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## notmrjohn (Aug 20, 2012)

Remember jo, no one disputes that wood burning appliances can be efficient, just that open face fireplace is very inefficient. Fire place may be _sufficient_ in some circumstances, perfectly acceptable, and even best way to go given circumstances, but still not the most _efficient_ producer of heat in same circumstances. Article used pelletized wood stove as example, stove tops fireplace, pelletized stove tops wood burning, automated pellet stove tops that,_ in producing heat._

Article wasn't really about efficency or non-efficiency, sub-title said it best "A standardized efficiency test method needs to be adopted by the hearth industry." Says standard to use is "energy return on investment" (EROI) and says when comparing wood to electricity that electrical line losses, energy lost in converting heat from coal to electricity, energy used mining coal, etc should be calculated in. ( liked the way they used dirty ol' disreputable coal instead of natural gas, hydro , wind or other.) Wood by contrast, according to article, only "entails a chain saw and a small truck." No mention of loss of woodlands, building and agricultural timber, erosion, muddied waters, loss of air purification, etc. ( But artical was from Hearth and Home Magazine) That comprehensive EROI is important in big picture. But for home owner HROI (Heat Return On Investment, my acronym) is main consideration. Amount of heat produced and distributed vs cost to home owner of appliance, and fuel in $ and labor in fueling unit. Once that's determined, other concerns such as EROI, conservation, pollution, aesthetics of appliance, etc can be addressed.


Was mostly concerned with mathematical theoretical comparisons, especially role of water vapor. Nifty little arrow at bottom showed _energy_ loss up chimney as smoke (potential energy in unburned particles) and water vapor (kinetic energy in warm water), leaving out loss of what we are trying to produce, warm air. Title said it all "Efficiency Is in the Eye of the Beholder" , here the beholder had vested interest in wood burning source of heat. I agree, some industry wide standard is needed, standard should be based on BTU's actually delivered to home by appliance at point of use. That should be determined by disinterested "beholders" using comparable actual measuring procedures, (similar to way Consumer Digest tests egg beaters for example) not "calculated " with mathematical formulae and perfect condition theories. ( Average egg has viscosity of X, Brand A has beaters of Y width, gear ratio of 5 to 7, ergo Brand a is best) Article even grants that "electric home heaters are nearly 100 percent efficient" at point of delivery and their "modern certified wood heater" has an "efficiency" of 75%, not counting actual heat up the chimney, hiding up in the text amongst a bunch of acronyms and Federal Register and appendix J, etc that the EPA rates "certified" stoves at 68%. 
Comparing wood to other fuels is comparing apples to oranges. Comparing open fire place to even wood stove is comparing orange juice to apple juice, trying to carry OJ in a sieve or cider in a bucket.

So, to answer your question, *miami*, yes, fireplaces have "vents." They are a method to make what in todays world is basically an aesthetic element of decor and ambiance (especially in Florida) into a _more_ efficient practical appliance.


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## jomama45 (Nov 13, 2008)

notmrjohn said:


> Remember jo, no one disputes that wood burning appliances can be efficient, just that open face fireplace is very inefficient. Fire place may be _sufficient_ in some circumstances, perfectly acceptable, and even best way to go given circumstances, but still not the most _efficient_ producer of heat in same circumstances. Article used pelletized wood stove as example, stove tops fireplace, pelletized stove tops wood burning, automated pellet stove tops that,_ in producing heat._
> 
> Article wasn't really about efficency or non-efficiency, sub-title said it best "A standardized efficiency test method needs to be adopted by the hearth industry." Says standard to use is "energy return on investment" (EROI) and says when comparing wood to electricity that electrical line losses, energy lost in converting heat from coal to electricity, energy used mining coal, etc should be calculated in. ( liked the way they used dirty ol' disreputable coal instead of natural gas, hydro , wind or other.) Wood by contrast, according to article, only "entails a chain saw and a small truck." No mention of loss of woodlands, building and agricultural timber, erosion, muddied waters, loss of air purification, etc. ( But artical was from Hearth and Home Magazine) That comprehensive EROI is important in big picture. But for home owner HROI (Heat Return On Investment, my acronym) is main consideration. Amount of heat produced and distributed vs cost to home owner of appliance, and fuel in $ and labor in fueling unit. Once that's determined, other concerns such as EROI, conservation, pollution, aesthetics of appliance, etc can be addressed.
> 
> ...


This is where your thought process, although it falls in line with most folks who also don't understand the process, completely misses the mark. Open faced FP's don't heat air, it's merely a side benefit of the radiant heat they produce so well. When you use conventional testing of "air heaters" and apply it to something that's not intended to heat air, what do you think the results will be??????


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