Burn Time vs. Blast Out

[Geoff]

In my search for a new stove, I’ve been pondering the stove size mainly due to burn time. My house is about 1300 square feet (650 on the main floor where the stove is, 650 upstairs) plus about 500ish in the basement that I don’t intend to heat with the stove. I’m gone 11 hours out of the day and I’d rather not have to build a new fire every night when I come home. However, I don’t want to overheat the house.

I live in central NH so it is usually pretty cold in the winter and the house has some leaks that should be repaired but is overall pretty well insulated. My current stove is about 25 years old and has about a 3.2 cubic foot firebox. It keeps one end of the house warm, especially the bedroom above it which can sometimes be too warm (when I load it up before bed and get it roaring before damping it down). I’ve been looking at stoves with good convection properties because our hearth is in one of the corners of the house so a stove that can help circulate the heat would make sense. One of the local dealers that sells Lopi stoves has the Liberty hooked up in the store. The shop is maybe 300 to 400 square feet and while that large stove was running it was quite warm inside but it wasn’t so hot that a window had to be opened. I don’t know if the shop is insulated and there is a large garage attached to the side which I doubt is heated by the stove… The woman told me that it could be damped down real low and still burn nicely so that it can heat a large range of areas. I’ve been looking at the Liberty and the Endeavor. The Endeavor might be a better fit for my hearth and the size of the house, but the Liberty might be better fit for my time.

I’m curious what others, who are concerned with long burn times but have houses that don’t necessarily justify a large stove, have done.

 

[babalu87]

Morso 3610 and I can get an honest 8-10 hours with enough hot coals to just add splits and get the stack temperature back where it needs to be
11 hours is an awefull long time to expect out of a wood stove

 

[Rob From Wisconsin]

You really only have two (2) choices to get longer burns:
1.) Get a CAT converter stove with a big fire box.
Longer, cleaner burns but typically less max heat output
2.) Get an EPA non-cat stove w/ a huge firebox & chimney that
drafts decently & crank it down as far as you reasonably can.
Long, but somewhat less cleaner burns than a CAT stove.
More heat can be requested by increaing air flow, but this
will significantly reduce your burn times...

Hope this gives you a perspective....

Rob

 

[wg_bent]

Sounds like you should be looking at Hearthstones or Woodstock stoves. The soapstove will give you a more even heat over a longer period of time. The big Lopi sounds like it would over heat your house. My smaller osburn can seriously over heat our living room if I let it, and it will provide about 7 hours of practical burn time on a full load of wood, but 11? That is a long time. I do know some of the folks with Pacific Energy Summits on this forum have had very good burn times though. Might look at them, but they are as large as the Lopi.

 

[Sandor]

Warren is correct.

Look at a Soapstone stove. I have a Woodstock, and highly recommend it. I have used 3 different steel/cast stoves over the years and the soapstone is tough to beat. 8-10 hour overnight burn times are very easy (with the smaller Keystone model) and the ability to burn slowly without the chimney looking like an 19th century freight train.

I would never recommend soapstone to a casual burner that wants lots of heat fast, occasionally. Go steel or cast for that.

If you want (or hope) 11 hour burn times, you need a soapstone stove with a cat. Period.

Honestly, 11 hours is kinda stretching it, no matter what you buy.

 

[Sundeep Arole]

The lopi declaration inserts advertise a 12 hour burn time. I don't know how trustworthy that is, but they do have a big firebox. I recall someone on this list who installed one recently (don't remember who) but perhaps they could give you a firsthand opinion with regard to those.

 

[Sundeep Arole]

Oops, just realized those declarations are inserts only. No stove version of those. Never mind.

 

[roac]

Blaze King seems to be popular here in the North West. Their King model brags a 40hr burn time on low. The firebox is 4.32 cubic foot and is a cat stove. Not sure what the burn time would be in real time but Chesley (member of the forum) just got one and might be able to tell you.

 

[Geoff]

The Lopi Liberty advertises a 10 to 12 hour burn time. The dealers (husband and wife) I talked to claimed that they got 13 hours out of the one they have at home….

I’d like to go with a cat stove to try to extend burn times but unfortunately I have poor draft due to too many necessary bends so a cat stove probably won’t work. I’ve thought about the soapstone stoves but I’m concerned that I won’t get even heat distribution to the opposite corner of the house relying on radiation alone. (I’d rather not have to use a fan if I don’t need to.)

As for long burn times: I usually have somewhat short burn times with my current stove (Upland 207). But last weekend I burned 24-7 for the three day weekend. I re-loaded Tuesday morning at 2AM. I raked the large bed of coals forward before I left the house around 7AM and left it damped down. I came home at 6PM and I had enough coals to get a fire going with some small splits and kindling. 16 hours! Unfortunately I can’t run this stove all the time because of the way it is set up, I need too many bends in the stove pipe which is messing up the draft, making it hard to get a fire going when its above 15°F. Otherwise I’d probably keep the stove a little longer.

Maybe some of my hopes for long burn times comes from the use of the wood/oil/coal furnace I used to use… I seem to remember that burning pretty long.

 

[Todd]

It sounds like your right in the same neighborhood as Woodstock. Maybe you should drive over there and check them out. I bought the Fireview because I wanted longer burn times while I was away at work for over 10 hrs. I have gotten over 12 hour burn times with my Fireview burning oak. Plus the extra heat life of the soapstone helps. The cat stoves are designed for a slow burn with more heat output than a non-cat stove.

 

[ERPARKER]

The lopi declaration inserts advertise a 12 hour burn time. I don't know how trustworthy that is, but they do have a big firebox. I recall someone on this list who installed one recently (don't remember who) but perhaps they could give you a firsthand opinion with regard to those.

I haven't made a serious attempt at an overnight burn in my Declaration. My wife and I both work so it seems like a lot of wood and effort to expend to try and heat up the house for the hour or so that we're out of the bed but not yet out of the house. I also have scrappy wood (pine, maple & oak) that I'm going through this season. I hope to experiment with overnight burns weekend evenings next season when my multiple cords of oak will be seasoned.

From what I've experienced so far I'm inclined to think it could make it a long time. I put just a big single log on top of a hefty pile of very hot coals in last night around 10:00 and the glass was still warm at 7:00 this morning. If I tried, I think I could have enough hot coals left to get the fire going quickly again.

 

[Swamp Fox]

I've got the Blaze King 1107 and have had it operational about one week. So far, I have loaded the stove three times, and only loaded it half full each time. After loading it and burning it hot for about an hour on max thermostat setting (#3) I burn it on a thermostat setting of about 1-3/4 to 2. At 24 hours there are still large chunks of coals and the cat is still active and the thermometer on top of the stove reads from 300 to 350 degrees. I am still learning the operation of the stove so, I haven't actually filled it completely full yet (manual says 90 pounds of wood). Manual also says stove operates better when you actually do fill the stove completly full.

 

[wg_bent]

Honestly, it sounds like your a perfect candidate for a coal stove!

 

[Geoff]

Todd,
I went to Woodstock (Soapstone not VT) maybe two months ago to look at the stoves. I really like the stoves and the company but unfortunately the right-side loading door just won't work in my situation. They're also catalytic and I'm concerned with the impact that might have on my poor draft.

Chesley,
The long burn times of the Blaze Kings are tempting, but it looks like they're all catalytic?

I guess this brings up the question: How much will a catalyst generally reduce draft? I know they're a restriction in the gas flow, but at the same time they re-ignite the gas so I'd assume the gas exiting out of the stove would be warm and may help encourage draft... One of the reasons I have poor draft right now is because my chimney has two approximately 45° bends in it (in the flue tile) and due to the existing stove I need to make two 90° bends to get into the chimney. I'm hoping to reduce these two 90° bends to 45° bends with a new stove that will allow this, leaving me with 4, 45° bends in all. So I'll be increasing draft with a new stove but I don't want to decrease it again with a device that may reduce draft (catalyst).

 

[Geoff]

Honestly, it sounds like your a perfect candidate for a coal stove!

Maybe if I dig deep enough I can mine my own coal!

My father told me that he had to pay more for coal this year because the Chineese were using a lot and driving up the price...

I guess if I wasn't planning on trying to heat mostly for free (wood) I might think about coal.

 

[Swamp Fox]

Geoff,
Draft issues may well be a concern in the Blaze King. The new manual now recommends a vertical rise of no less than 36 inches, and they recommend double wall pipe to keep the heat in. I was told some people were having problems with their stoves not working because of poor draft (coming out of the stove and putting a ninety in almost immediately). I have a 32 inch vertical rise and a ninety into my SS lined and insulated chimney. With the new stove, I replaced the 90 degree elbow with two 45's. I am having no draft problems.

 

[roac]

The only non-cat stove that I know of with really long burn times is the Pacific Energy Summit. Maybe someone will chime in shortly about theirs. Unfortunately the non-cats have smaller fireboxes due to their secondary combustion chamber. PE Summit I believe is 3.0 cu. ft. Englander makes a 3.5 cu. ft. stove (ncl-30)but I'm not sure what kind of burn time that non cat gets. Most of these cat stoves have a bi-metallic coil that acts like a thermostat which helps the burn time. The PE Summit has something similar.

 

[Todd]

Todd,
I went to Woodstock (Soapstone not VT) maybe two months ago to look at the stoves. I really like the stoves and the company but unfortunately the right-side loading door just won't work in my situation. They're also catalytic and I'm concerned with the impact that might have on my poor draft.

Chesley,
The long burn times of the Blaze Kings are tempting, but it looks like they're all catalytic?

I guess this brings up the question: How much will a catalyst generally reduce draft? I know they're a restriction in the gas flow, but at the same time they re-ignite the gas so I'd assume the gas exiting out of the stove would be warm and may help encourage draft... One of the reasons I have poor draft right now is because my chimney has two approximately 45° bends in it (in the flue tile) and due to the existing stove I need to make two 90° bends to get into the chimney. I'm hoping to reduce these two 90° bends to 45° bends with a new stove that will allow this, leaving me with 4, 45° bends in all. So I'll be increasing draft with a new stove but I don't want to decrease it again with a device that may reduce draft (catalyst).

You say you have a poor draft now? What kind of chimney and setup do you have now? A stainless steel liner does wonders for draft in masonary chimneys. I was worried about my draft to. I have an outside brick chimney with 3 90 deg elbows, and my new stove drafts better than the old one. Don't give up on the cats just yet. I think the older ones may be more draft sensitive than newer models.

 

[bruce]

my harman will go 12 hr and have enough to stir up a new fire
i loads mine at 630 am and dont get home untill 5 30 and dont have to relite
every one i talked to said to stay away from the cat stoves

 

[Todd]

I've got the Blaze King 1107 and have had it operational about one week. So far, I have loaded the stove three times, and only loaded it half full each time. After loading it and burning it hot for about an hour on max thermostat setting (#3) I burn it on a thermostat setting of about 1-3/4 to 2. At 24 hours there are still large chunks of coals and the cat is still active and the thermometer on top of the stove reads from 300 to 350 degrees. I am still learning the operation of the stove so, I haven't actually filled it completely full yet (manual says 90 pounds of wood). Manual also says stove operates better when you actually do fill the stove completly full.

90 lbs of wood? Holy cow!! That stove must be the size of a wood boiler?

 

[Swamp Fox]

Blaze King 1107 = 4.32 cubic ft. fire box.

 

[roac]

90 lbs of wood? Holy cow!! That stove must be the size of a wood boiler?

Yeah at 2.18 cu. ft. the Fireview is about half the size.

 

[wg_bent]

Woah blaze king. That's a furnace! Osburn 2400, 3.2 cuft

 

[fespo]

I have the lopi Liberty. My house is about 1850 sq ft ( not counting the basement) with an open family room/ kitchen area. When I. burn oak and pack the stove full all the WAY. I can get a good 8 to 10 hours of a burn time. If you call a choked down slow fire a good burn for 8 hours, but it will put out heat.. I pack the stove around 9pm and at 5am when I get up for work I just throw on more logs and poof I have a fire again. To get that 8 hour burn time I have a bed of coals about 1 1/2 to 2" of
I do like to get the house as warm as I can when the temps fall around 10 and lower. That way, through out the night the house stays warm when the stove can not keep up with the temp loss.
.

 

[Geoff]

You say you have a poor draft now? What kind of chimney and setup do you have now? A stainless steel liner does wonders for draft in masonary chimneys. I was worried about my draft to. I have an outside brick chimney with 3 90 deg elbows, and my new stove drafts better than the old one. Don't give up on the cats just yet. I think the older ones may be more draft sensitive than newer models.

My setup right now is like this:
7" oval to 7" round for 11" exiting the top of the stove
7" to 6" reducer
6" diameter 90° (backwards)
12" horizontal of 6" diameter pipe with about 1/2" of rise over the length
6" diameter 90° (upwards)
Through 6" thimble into 7" x 7" flue tile at approximately 45°
12" at the 45° angle, then another 45° to go straight up again
About 10' of straight up 7" x 7" flue tile lined brick chimney which is between an exterior and interior wall
About 2 or 3' straight up above roof of the 7" x 7" flue tile lined brick chimney
At the top of the existing chimney I added 6' of 6" round Simpson Duravent insulated SS chimney and a cap to help satisfy the 2-3-10 rule. I would have gone with an 8" round addition on top of the chimney (which I already had and didn't need to buy) but I was afraid of junk slipping down the chimney then landing on top of the brick chimney and running down it and making a mess.

I've attached some drawings of the hearth setup (no stove or stove pipe) to clarify the beginning of the chimney with the 45° bends in it. I also attached a photo (from the real-estate ad from when I bought the place in November) of the gas stove that I pulled out, you can sort of see the two 90° bends in the stove pipe.

I'm planning on adding a 6" stainless steel flex liner to the chimney when I install a new stove. I may try to insulate around between the stainless liner and the flue tile if I can.