How long does your fireplace burn?

[jinman]

Every morning I get up and start a fire in our fireplace. My normal routine is to put a big back-log on the rear of the grate and then roll up a sheet of newspaper and put it directly in front of the backlog. I then put on one of those fire starter bricks and stack a small log in front of the paper and put another directly on top of the paper and starter brick. If there is room, I place a 4th log in the middle of the stack.

With this done, I strike a match and light the newspaper at both ends and in the middle from beneath the stack. I leave the damper full open while I make coffee and my breakfast, then close it down about 2/3 when the fire strarts to go really well.

I use mostly oak, postoak and blackjack oak, for my firewood. With this stacking method, my fire starts and burns very nicely with a crackling fire for easily 2-1/2 to 3 hours without adding more wood. This morning I just noticed the fire burning with a nice full flame and still three substantial logs red with coals after 2-1/2 hours of burning.

For you folks with more experience, am I right in thinking that I am getting a very long burn for the amount of wood on my grate? This just seems like a long time to me. Later in the day, as I add to the fire, I'll have to add a single log every 3/4 hour to 1 hour to keep a nice fire going all day, but my original stack in the morning seems to burn very long with little assistance. I suspect I am being spoiled by my oak firewood. What do you think?

 

[Western]

We also burn mostly oaks, a little elm, ( hate splitting elm), but mostly an assortment of oaks on our place.

We always have a fire when we are home and the temps are 50 degrees or less, which has been pretty much all the time now.

Jinman, your fire seems par with ours. Sometimes I get a slow burn average heat with greener wood, the dryer wood seems to burn faster but hotter. I don't have a damper really, just the main in the chimney base but that's a open/closed thing since ours is a standard built in type.

I have had some really good "free standing" wood stoves that you could really control the burn to where a couple of descent size logs would burn most of the night, top it off with a fan and they can be a real contributor to the comfort level.

I like free standing better than the built-ins personally, they seem much more efficient to me..and you get a little more heat from the piping, ofcourse a well designed fire place can be a huge improvement to the "wall set" like I have..

 

[carpenter383]

Yes oak is very dense wood so it will burn longer especially in rounds. Oak takes a long time to season, Some say in needs up to 3 yrs after being split and stacked to drop to 20 percent moisture content.
I don't have a fireplace, but I am using an outdoor wood boiler to heat my home and my garage. So far with temps in the mid thirties I can go about 30 hrs on a load of hardwood.

 

[MossRoad]

Jinman,
Do you have a fireplace or a wood burner? I ask because you mention a damper. I don't think fireplaces have dampers. Maybe a wood burning insert for a fireplace?

Anyhow,
We bought a wood burning stove last year. I build a fire similar to how you do it except on top of the newspaper I lay kindling wood instead of a fire starter. I also stuff the stove completely full of wood per the instructions that came with it. I light it up and off it goes. I let it burn with the air control (we don't have a damper) full open for about 1/2 hour or until the stove top gets to 500 degrees. Then I shut the air conrtrol all the way closed. From there it burns very nicely. Here are the results of my use of different wood types.

Sassafras = nice hot fire for approximately 4 hours with not much ash or coals left.
Oak and Cherry = 6 hours, but leaves a lot of charcoal.
Locust = 8 hours of burn with almost nothing left.
Of course, a mix of these woods makes different results.

This year started burning Oct. 1st. and have only let it burn out 4 days. Otherwise continuous burn. When temps outside are above 25 I can keep the house at 70-72 very easily averaging about 3 stokes a day. If it gets below 25 my usage goes up and I have to load more often.

We put a duct from above the wood burner in the basement to the floor in the center of the house. It has an in-line fan in the duct and a thermostat to control it. When the basement gets above 78 degrees, the fan kicks on and pushes the hot air up to the first floor. When the fire goes down and the basement cools below 78 degrees the fan kicks off so cool air does not get pushed upstairs. The furnace thermostat is on the first floor and is set to 70 so it will keep the house comfortable should the fire die out. Our goal was to cut our gas usage in half with the wood burner. I think we have gone more like 75-80%. Our gas bill for October was $22.00 and our bill for November was $35.00.

 

[jinman]

Jinman,
Do you have a fireplace or a wood burner? I ask because you mention a damper. I don't think fireplaces have dampers. Maybe a wood burning insert for a fireplace?

Moss, we have a regular (very large) fireplace surrounded by firebrick and what we have is not a damper, but a large rectangular door opening into the chimney. My use of "damper" was a misnomer. My mechanism for the door is stiff enough that I can close the door down somewhat like a damper but with nowhere near the accuracy of a true damper. I'd say I leave my door open 1/3 most of the time and that's enough to have plenty of draft and not leak any smoke out into the room. Our chimney is made of tiles surrounded by filler brick and then outside brick and mortar. The fireplace is a little unusual in that the brick starts on the walkout basement level and the actual fireplace opening is on the floor above. If I had been smart, I'd have asked the contractor to include a metal chimney up from the basement level and have dual stacks within one brick enclosure.

Construction pictures are shown attached.

 

[JB4310]

For you folks with more experience, am I right in thinking that I am getting a very long burn for the amount of wood on my grate? This just seems like a long time to me. Later in the day, as I add to the fire, I'll have to add a single log every 3/4 hour to 1 hour to keep a nice fire going all day, but my original stack in the morning seems to burn very long with little assistance. I suspect I am being spoiled by my oak firewood. What do you think?

Nice looking fireplace and raised hearth,

To your question,
I would say so, I don't get anywhere near that time between adding more wood. Are your logs 12+ inches in diameter and 3 ft long?

I'm constantly poking around in there until I get a good bed of coals. Much different starting technique also, I don't add larger logs till after the smaller stuff is really going good, I use one of those starter bricks and a few smaller 3" stuff to get started, gets burning nicely in just a few minutes.

Wood of choice for fire place is first: Hickory, next: White Oak, next: Maple.
IMO Red Oak is to hard for fireplace burning and has to be turned and fussed with to get a nice burn, probably the best for stoves though.

 

[Egon]

Wood of choice for fire place is first:

For me it's whatever I have available!

Jinman, you should be able to fit a real nice airtight insert into that fireplace!

 

[JB4310]

Moss, we have a regular (very large) fireplace surrounded by firebrick and what we have is not a damper, but a large rectangular door opening into the chimney. My use of "damper" was a misnomer. My mechanism for the door is stiff enough that I can close the door down somewhat like a damper but with nowhere near the accuracy of a true damper.

What you have IS a Damper, never heard of it called anything else.

fireplace damper - Google Search

May be another of those geographical sensitive terms, but I've worked on a thousand chimneys and it's a damper, or at least around here it is

JB.

 

[jinman]

What you have IS a Damper, never heard of it called anything else.

fireplace damper - Google Search

May be another of those geographical sensitive terms, but I've worked on a thousand chimneys and it's a damper, or at least around here it is

JB.

JB, you are correct. I went back and looked at construction photos and found the one below. My damper is a Vestal HT-42 High Top. Of course, my fireplace doesn't add much if any warmth to the room, but it sure is toasty if you stand in front of it due to radiant heat. If we ever want any real heat from it, we will have to install an insert as Egon suggested or completely redo the fireplace with blowers and ductwork to attach to our central heat/air system. Right now it is mostly for looks.

Our wood is split oak. The wedges are 6" maximum at the thick side by 16" long. The heaviest is about 10 lb with most being in the 7 lb range. We split trees that have been dead and standing for about 3 years. Blackjack oak is a very hard wood and burns best when mixed with postoak. If it is dry and you are cutting at night, you'll see lots of sparks off your chainsaw blade. I have not let my wood cure since I cut and split it. If it didn't dry while standing dead, it hasn't had time to dry since I stacked it. It is easy to start a fire with by using only a single sheet of newsprint and one small 1"x2"x6" starter brick.

I am far from a fireplace expert, but I leave a bed of ash under the grate and pull coals forward as they build up under the fire. It doesn't take much work to keep the fire going.

 

[beenthere]

Sounds like you are doing well with the oak wood, and the only thing I would do different is get rid of the grates. Keep a few inches of ashes in the bottom, and they will support the hot coals, and let you get even longer fires from the same amount of wood. Don't need that much air circulating under the fire. IMO

And glad you got the damper name straightened out for posterity, if for no other reason.

But have learned that each fireplace can be a bit different and have to get the operator "trained" to learn the intracacies for best burning.

 

[MossRoad]

Moss, we have a regular (very large) fireplace surrounded by firebrick and what we have is not a damper, but a large rectangular door opening into the chimney. My use of "damper" was a misnomer. My mechanism for the door is stiff enough that I can close the door down somewhat like a damper but with nowhere near the accuracy of a true damper. I'd say I leave my door open 1/3 most of the time and that's enough to have plenty of draft and not leak any smoke out into the room. Our chimney is made of tiles surrounded by filler brick and then outside brick and mortar. The fireplace is a little unusual in that the brick starts on the walkout basement level and the actual fireplace opening is on the floor above. If I had been smart, I'd have asked the contractor to include a metal chimney up from the basement level and have dual stacks within one brick enclosure.

Construction pictures are shown attached.

Beautiful home you have there.

 

[MossRoad]

What I remember about dampers in chimneys is my dad starting a fire on a cold winter morning and promptly filling the house with smoke because the damper was closed. I guess in a fireplace you would not use the damper to control the fire, would you? You would just use it to close the chimney after the fire was out to prevent heat loss in the house, correct?

 

[JB4310]

I read somewhere that one of the oak species has the highest BTU potential, not sure which one though.

As far as using damper to try and control the draft and heat goes, some people do it but most just leave it wide open.
Some may not realize but with a fireplace, that flue can be a 2 way street not only venting gasses up but drawing combustion air downwards, especially in a well insulated "tight" house with little source of make up air.

The taller the chimney the better the draft usually, but there are all kinds of factors that can cause a fireplace to not function well. Make up air is a biggie but also any other oxygen gobbler in the house, like gas or worse, oil fired furnaces, even clothes dryers venting outside.
Depending on which one is more starved for air, can make it difficult to diagnose/figure out why there is smoke, odor or worst co2 in the house. That's sometimes referred to as "stacking" where one appliance will pull it's combustion air through another's exhaust.

Here's a pic of my F/P in the basement cave, this one sits at floor level, I'd rather have the raised hearth of Jim's. I have a steel box to keep the logs in with a grate underneath, that raises the fire off the bottom about 4 inches. My house was built in 1936, there's another FP right above this one in the living room but we don't use it much except for the occasional fake log.

 

[ultrarunner]

I have a Austrian kachelofen ceramic wood stove at the cabin...

One armful of hardwood lasts 24 hours...

If it is freezing outside it's one armful of hardwood every 12 hours.

For those interested... here's what Mark Twain had to say about Kachelofens:

The German stove (Kachelofen)] is by long odds the best stove and the most convenient and economical that has yet been invented. One firing is enough for the day; the cost is next to nothing; the heat produced is the same all day, instead of too hot and too cold by turns; one may absorb himself in his business in peace; he does not need to feel any anxieties of solicitudes about the fire; his whole day is a realized dream of bodily comfort.
The American wood stove, of whatsoever breed, it is a terror. There can be no tranquility of mind where it is. It requires more attention than a baby. It has to be fed every little while, it has to be watched all the time; and for all reward you are roasted half your time and frozen the other half. It warms no part of the room but its own part; it breeds headaches and suffocation, and makes one痴 skin feel dry and feverish; and, when your wood bill comes in, you think you have been supporting a volcano.

- Mark Twain, 1891
excerpted from 鉄ome National Stupidities, from Europe and Elsewhere, Harper & Brothers,1923.

 

[jinman]

Beautiful home you have there.

Thanks Moss. We love the house, but there are lots of things I'd change if I were doing it again. As time and money allows, I may do some of those in the future. Three floor levels with only one HVAC system is a challenge. Today, we have our main living area at 69-70 degrees, but my basement is only 59. I wish I had a wood stove there to boost the temperature a bit in winter. In the summer, it's the best spot in the house.

JB, I like your "cave" fireplace. It's easy to see that it's had a lot of use. I don't think I have any venting problems with my fireplace. In the morning I set my thermostat up from the night temperature of 62 to 70 and then start the F/P. With the damper door all the way open, I've never had any smoke or downdraft of cold air. It draws nicely.

While I welcome all comments (I'm learning alot.), my original comments were to see how the average stack of wood burns in a normal fireplace. I think what I'm finding is there is a large variation based on wood type, dryness, size of pieces, and style of fireplace. I'm very happy with my own fireplace experience so far, but there could be lots of improvements. A wellmade woodburning stove could surely save a bunch on my winter electric bills.

 

[radioman]

try an armfull of hickory!

 

[beenthere]

What I remember about dampers in chimneys is my dad starting a fire on a cold winter morning and promptly filling the house with smoke because the damper was closed. I guess in a fireplace you would not use the damper to control the fire, would you? You would just use it to close the chimney after the fire was out to prevent heat loss in the house, correct?

MossRoad
Not correct the way I use the damper in my house fireplaces. I open the damper to get the fire going and a good draft to warm up the chimney. Then as the chimney and brick get warm, close the damper to just enough to let the smoke up, and not a rush of room air going up the chimney. In fact I close the damper all the way, and immediately crank it open just a smidgen. Maybe a 1/4". Plenty of heat to carry the gases and smoke out.
Each chimney is a bit different and some experimenting needs to be done. Type of wood, type of chimney, the way the fireplace is built, sources of make-up air in the house, dryer and bathroom and oven exhaust vents are all factors to figure into the right procedure.

 

[JB4310]

I wish I had a wood stove there to boost the temperature a bit in winter. In the summer, it's the best spot in the house.

You may be able to still do it, it would of been simple with clay liners during construction, but even now that chimney is hollow from top to bottom, with a little effort you could drop a stainless steel pipe in. The only trouble and this is a biggie, is getting past the fire box, it's not gonna just drop in there and would probably require some modding, should still be able to be done from outside with out disruption to your fire place, you'd only need about 6-7 inches to get that pipe through. then just a thimble breech in the basement and another through the top crown.

JB.

 

[dex3361]

You may be able to still do it, it would of been simple with clay liners during construction, but even now that chimney is hollow from top to bottom, with a little effort you could drop a stainless steel pipe in. The only trouble and this is a biggie, is getting past the fire box, it's not gonna just drop in there and would probably require some modding, should still be able to be done from outside with out disruption to your fire place, you'd only need about 6-7 inches to get that pipe through. then just a thimble breech in the basement and another through the top crown.

JB.

This is what I did to my Wood stove, I have a clay tile liner and I dropped in a 8 inch Stainless steel liner it was in 3 foot sections and I put it together with SS screws. The thing that noticed the most was that my chimney stays very clean it typically drops all of the creosote back down as hard flakes. I made a thimble for the top of steel plate and pipe and put a shroud of ss around it. I brought it down and tied it directly into the Harmon Stove it is a coal/wood stove that work well with or without the blower. I went this route because of power outages like the one we just went through that lasted for 6 days. With the shaker grate you never have to shut down the stove you can clean out the ashes in the bottom with a fire roaring. It will burn 10 hours if I choke it down a bit. I really like the Harmon stove it has a nice rustic look and it is easy to start a fire in.

 

[MarkV]

Jim I think you are getting a good burn time for an open fireplace. My guess is that much of it has to do with using Post Oak, sometimes called Iron Oak, and Blackjack Oak. These are both very slow growing species that are very dense. When well cured they will burn a long time with good BTU out put. It also sounds as if some of your wood may be a bit under cured which will make it burn slow. Not a big problem if you are getting the results you like. You may lose some BTU output and you will want to watch for creosote build up in your chimney.

MarkV