Red Fir Firewood - Am I missing Something?

[Ben]

I mentioned that I got behind last year in my firewood processing and need to buy a cord of wood to supplement my stock for the upcoming season.

Anyways, I was checking the Craigslist for mixed hardwood, and I am seeing a bunch of red fir, which I guess is easily available in the region. The thing is, AFAIK, "red fir" is just a regular softwood, like pine, that burns hot but burns quick. However, the red fir around here is all going for $300-$375/cord, while the mixed hardwood is going for $275-$350. While the images of the red fir look really good, I'm trying to figure out why a softwood is going for more than the hardwoods. Does anyone know if there is anything special about red fir?

[charby]

Red fir is a high elevation fir from western California and Oregon.

Should burn like any conifer. Weird that it is being sold where you are unless its subalpine fir or douglas fir, misidentified.

[Ben]

Should burn like any conifer. Weird that it is being sold where you are unless its subalpine fir or douglas fir, misidentified.

I'm thinking misidentified or otherwise it has somehow become a regionally common name for something else. In googling, I've found a lot of references to "red fir" as an Idaho tree. I've only found images of the split firewood. I haven't found any images of the tree that they are calling "red fir". Whatever it is, it is being locally harvested in the mountains, because the firewood ads are all from local firewood/lumberjack type guys.

[zxcvbob]

I mentioned that I got behind last year in my firewood processing and need to buy a cord of wood to supplement my stock for the upcoming season.

Anyways, I was checking the Craigslist for mixed hardwood, and I am seeing a bunch of red fir, which I guess is easily available in the region. The thing is, AFAIK, "red fir" is just a regular softwood, like pine, that burns hot but burns quick. However, the red fir around here is all going for $300-$375/cord, while the mixed hardwood is going for $275-$350. While the images of the red fir look really good, I'm trying to figure out why a softwood is going for more than the hardwoods. Does anyone know if there is anything special about red fir?

How much does it weigh per cord?  That should be a good indication (after adjusting for moisture content) of how many BTUs you get.  Hardwood/softwood doesn't matter; cottonwood and basswood are hardwoods.

[Ben]

How much does it weigh per cord?  That should be a good indication (after adjusting for moisture content) of how many BTUs you get.  Hardwood/softwood doesn't matter; cottonwood and basswood are hardwoods.

I don't know weight, but I found an Idaho arborist site that suggested it's a regional name for Douglas fir. I found this on burning Doug fir:

https://downtoearthhomesteaders.com/is-fir-good-for-firewood/

The BTU listed in the article is only a couple lower than the Russian olive hardwood that I harvest off my place, so it might be a good wood to get. It certainly seems to be more popular in these parts than mixed hardwood (which we have little of anyway). Apparently Doug fir isn't technically a fir itself, being more dense than other firs.

[JTHunter]

Ben - don't get it for firewood !!
Any "softwood" like fir and pine has too much resin in the wood to be burned safely.  Softwoods and that resin are what make creosote in your chimney.  The only safe place to use softwoods are outside OR as starter only (aka kindling).

[charby]

Ben - don't get it for firewood !!
Any "softwood" like fir and pine has too much resin in the wood to be burned safely.  Softwoods and that resin are what make creosote in your chimney.  The only safe place to use softwoods are outside OR as starter only (aka kindling).

They burn the sh*t out of conifers in wood stoves in the conifer forest areas. West, North, lake states and NE.

[K Frame]

Yep, you can very safely burn conifer IF you dry the hell out of it and you make sure to get the flue hot enough at least once a day to move any accumulated flammable material out of the flue pipe.

The amount of sap or resin in a wood isn't indicative of how much creosote it will leave in the flue. Any wood will leave flammable deposits in a flue if the fire isn't burned hot enough, and one of the big reasons why fires don't get hot enough is that the wood isn't properly seasoned to below... I want to say 15% moisture content.

Ben, I think you've said that you have a flue thermometer on your stove -- that's a VERY good thing to have.

If you do burn primarily pine or other conifers, you should also inspect your flue at least twice a season to make sure that you're not getting creosote build up.

[Ben]

They burn the sh*t out of conifers in wood stoves in the conifer forest areas. West, North, lake states and NE.

Yeah, nobody in Alaska would be able to heat their homes via wood if they couldn't burn soft wood.

Mike, yes on the thermometer. I have redneck kiln storage (a disused grain bin) for the wood I burn in an upcoming season, and all that wood is almost too dry. It mostly shows around 10% on the moisture meter. I mostly mix the Russian olive with pine. If I get this red (doug) fir, from my reading, it's more dense than other soft wood. From my research, it appears to be "the" wood to burn in this region. I'll still mix it with the Russian olive.

Both times that I've had the chimney sweep out, he's gotten little soot out and told me there was little build up. The last professional cleaning was after two seasons. I attribute a lot of that to the efficient Napoleon stove that came with the place.

[K Frame]

Douglas Fir only shows to have about 18.1 million BTU per cord, which is at the top of the list for soft woods, but still below any of the common hardwoods.

Osage Orange is a surprising one... it has the highest BTU value per cord, at 32.9 million.

Hum...

I'm finding some significant disagreements between the two charts I'm looking at. One says that DF has 26.5 million BTU per cord.


10%? You're right, that is almost too dry. I'd open those 'kiln' doors and let natural atmosphere get in there for the summer to get some of the moisture content up. Otherwise, you're wasting BTU in flammable gases that can't combust in your stove and are just going out the chimney.

[Ben]

Hum...

I'm finding some significant disagreements between the two charts I'm looking at. One says that DF has 26.5 million BTU per cord.


10%? You're right, that is almost too dry. I'd open those 'kiln' doors and let natural atmosphere get in there for the summer to get some of the moisture content up. Otherwise, you're wasting BTU in flammable gases that can't combust in your stove and are just going out the chimney.

Yeah, I saw the same charts I think. The one article I read mentioned that and sort of "averaged" it to 22.

On the kiln, yeah. though it has rooftop ventilation, I do open the door a good bit through the Summer. I've additionally built a three sided woodshed next to it, and am looking at coming up with a system where the wood starts in the shed, and then maybe towards the end of Summer, I move that season's wood into the kiln.

[charby]

Conifers as a whole, typically have higher BTU than the common hardwoods, but conifer woods release the BTU with a faster burn, due to the resins in the wood.

Douglas Fir, as Ben mentioned isn't a fir species, even the latin names states that pseudotsuga menziesii. It's actually in the pine family, pseudotsuga translated means false hemlock. I've tried to research if firs (Abies) were once classified as hemlocks and then given their own species. Haven't found anything yet.

[RoadKingLarry]

Yep, you can very safely burn conifer IF you dry the hell out of it and you make sure to get the flue hot enough at least once a day to move any accumulated flammable material out of the flue pipe.

The amount of sap or resin in a wood isn't indicative of how much creosote it will leave in the flue. Any wood will leave flammable deposits in a flue if the fire isn't burned hot enough, and one of the big reasons why fires don't get hot enough is that the wood isn't properly seasoned to below... I want to say 15% moisture content.

Ben, I think you've said that you have a flue thermometer on your stove -- that's a VERY good thing to have.

If you do burn primarily pine or other conifers, you should also inspect your flue at least twice a season to make sure that you're not getting creosote build up.

Under 20% moisture content is fine. The key is to not burn low temp, smoldering  fires. I'll even burn Ash at up to 25% if I've got a hot enough bed of coals going.

[cordex]

Conifers as a whole, typically have higher BTU than the common hardwoods, but conifer woods release the BTU with a faster burn, due to the resins in the wood.

Conifers have a higher BTU?  I thought that by weight most woods are comparable but softwood’s lower average density means that for a given volume most hardwoods have more BTU.

[charby]

Conifers have a higher BTU?  I thought that by weight most woods are comparable but softwood’s lower average density means that for a given volume most hardwoods have more BTU.

Something I remembered from my wood products class.

Yes, there is outliers with hardwood having a higher BTU, but looking at all species available the conifers have a higher average BTU, but they burn quicker.

[Ben]

These BTU charts are all over the place, with seemingly every chart listing the same wood at a different BTU, but as an example:

https://www.firewood-for-life.com/firewood-btu.html

What I've seen is that there is no hard and fast rule on softwood or hardwood having a higher BTU. Some hardwoods are higher than some softwoods, and vice-versa. Fruit wood seems to have a consistently high BTU number.

[charby]

Appears Douglas fir is the highest BTU conifer available in Ben's QTH.

[Ben]

Semi-necro.

I pulled the trigger on the red fir and it got dropped off just a little bit ago. Turns out the guy is only a few miles from me, so free delivery with his dump bed.

Anyways, this stuff looks and smells pine-y. I picked out a hunk of lodgepole pine from the woodshed that had about the same size and mositure content (15%) as a log from the fir pile. The fir is definitely heavier and denser. The guy told me of all the wood he sells, the red fir is about the most popular. Moreso even than the limited quantities of mixed hardwoods he gets.  In fact the red fir goes more $25 more per cord than his hardwood. Really nice looking wood. I guess we'll see how she does come October.

[Bogie]

Back on the farm in Kentucky, we had a half-dozen phone/electric poles that were no longer used. So I took them out.
 
It appears that they were some variety of cedar/knotty pine. They'd been dipped in creosote or something for what was in the ground, to about a foot or two up.
 
Oh... And they dated from the 1930s...
 
I loafed 'em to about a foot long, and split 'em down to about eighths... A couple of those would get things going nicely.

[Brad Johnson]

Back on the farm in Kentucky, we had a half-dozen phone/electric poles that were no longer used. So I took them out.
 
It appears that they were some variety of cedar/knotty pine. They'd been dipped in creosote or something for what was in the ground, to about a foot or two up.
 
Oh... And they dated from the 1930s...
 
I loafed 'em to about a foot long, and split 'em down to about eighths... A couple of those would get things going nicely.

Bad idea. You're right about the creosote. Only they weren't dipped in it, they were boiled. It'll soot up your chimney something fierce. Smelly, too.

Brad

[sumpnz]

Yeah, no problem burning pine or fir in a wood stove, even exclusively, just needs to be under 20% moisture.  And if you have a catalytic stove you can even do a low, smoldering fire. 

Creosote is formed by the interaction of unburned particles with water vapor.  It won’t form (or at least to a vastly lesser extent) in stoves burning properly dried wood.  Resin content is a very small factor in creosote formation.  Wet oak will make more creosote than dry pine/fir.

[Bogie]

They were tarred for about a foot or so above the ground (and below). Above that, they looked fine. I put the tarred chunks in the springtime burn pile, and left the stuff in the ground in the ground...
 
And I wasn't burning it exclusively - just to start the stove.

[K Frame]

I've burned creosoted wood in open fires. My God is it nasty. Gives a tire a run for its money on how bad it is.