slabs vs good wood

[petefrom bearswamp]

Just changed over from my summer stoking of semi dry Hemlock slabs to heat domestic water to my 2 yr dried hardwood for winter.
I sit in my hot tub every evening and watch the furnace while soaking. when the slab load came on it took about 15 to 20 minutes to get to temp
tonight with good wood it took 8- 1/2 minutes 28 degrees outside temp.
this is with a 12 yr old classic set at 140 to 150.
also another point I tried to raise the temp back up to my usual setting of 160 to 170 but the computer wont let me change the setting.
I cant legally burn my slabs in a pile anymore in NY so decided to use the classic.
I make more slabs tan the unit can burn darn it.

[starmac]

Quite a bit of difference.
The sawmill here also sells firewood, and cuts and sells the slabs at a cut rate, I do not know how much of them they sell though.

[Ianab]

Semi-dry is likely the difference? DRY sawmill slabs should put out good heat, just that softwood tends to burn pretty fast, so it wont last as long. Of course if you have bark still on the slabs, that's not going to burn as well either.

BTUs per pound are similar for all woods, but of course a denser hardwood has more pounds, so more BTUs.