Help me put things in perspective.....old school wood furnaces vs new ones

[JRHAWK9]

I recently installed my very first wood burning heating appliance (Kuuma Vapor Fire 100) and seeing I have nothing to compare it to I'm just wondering how much wood you guys used to burn back when there was no such thing as secondary burns, etc....? Not necessarily the total per heating season, but how often and how much you would have to load it every day.

I'm currently trying to dial in my wood consumption vs heating requirement. I don't want to needlessly burn wood just to burn it and keep my house warmer than what it needs to be. It's been in the low-mid teens at night and low-mid 20's during the day here lately. I've gradually reduced my 10 hour loadings I do at night and during the day (when I'm gone to work) in order to try to balance wood consumption to heating requirement. Last night I put in a load of smaller split hardwoods. The load, sitting on the floor, measured about 12" x 12" x 16" and consisted of 9 pieces of wood (I did throw an additional pine split in after I measured just because the load sitting in the firebox did not look like a lot). When I got up 9.5 hours later the house was at 70° (was at 72° when we went to bed). There were still a decent amount of coals left to easily get the fire back going and the fan kicked back in about 5-10 minutes after I re-loaded. This, for me, would be the perfect loading for these temps. Balancing heat load with wood consumption. The computer on the furnace is always set to the minimum setting so far.

Anyway, just would like to hear from those of you who have been burning for awhile and have recently gone from an old school furnace to a newer efficient EPA one and compare your loading amounts and times for each setup. What I'm currently using seems like it would be on the low side but with nothing to compare it to I really have no clue.

We have a log cabin style house with loft and unfinished basement. Not a lot of area, but a lot of volume with the 30' ceilings and no attic.

 

[STIHLY DAN]

That is really good, I can't do that.

 

[JRHAWK9]

I am very pleased with how everything turned out. With these temps we are having already, without this furnace we would have had the flannel sheets and multiple comforters on the bed already in order to keep warm at night. We still have the summer satin sheets and I sleep with just a sheet over me. My GF is lovin' it. I keep my draft at 0.06" as best I can.

Did you used to have an old school furnace?

 

[STIHLY DAN]

No. oil boiler, t-stat at 62*. Now 70* to 76* what ever the wife wants. Did a wood stove in the basement before the furnace, but hated that. Way to much work and time.

 

[laynes69]

Our old woodfurnace would require solid rounds of locust, ash or dead elm of anywhere from 6-12" in diameter to take us thru the night when it was cold. Anywhere from 6 to 8 of them, and many times if I overslept on the weekends (past 6 am) I would wake up to a house at 68 or below and a cold furnace. The old furnace had a 6.5 cuft firebox that we would stuff and hope to see an 8 hour burn at night. I remember the last year we used it, I went thru over a cord of wood in the mild month of march. We never had extra wood left over from the season, and we had to sweep every month to month and a half removing buckets of creosote from our chimney. Also the house would spike to 80 then drop like a rock. It kept us warm, but many seasons was using probably 10+ cord a winter depending on the weather.

Since we bought our new woodfurnace, I've upgraded insulation in our home and concentrated on airsealing. We now have a furnace with a firebox size of 3.5 cuft. I have yet to fill the firebox at night and I wake to a 72 degree house after 8 hours when it's in the teens. Last night it was in the mid to low 20's and I loaded at 10:30 pm and woke at 8:30 am on 4 decent splits. The thermostat was set at 72, it was 71 with the damper open. I can sleep in, I always have a coalbed in the am, the house stays within a degree or two of the set temperature, wood consumption has dropped, and wood species doesn't matter anymore. No more burning large splits, and whenever I sweep the chimney I see coffee can amounts, not buckets from our 32' chimney. After installing our furnace, I now have excess wood left over and I can get ahead. As I concentrate on airsealing and insulation on our home, things only improve. There's a night and day difference between the old wood furnaces and the new modern furnaces.

 

[JRHAWK9]

wow.....that is quite the difference! thanks for sharing.

 

[cheechblu]

I have an old school tri-fuel furnace that can eat wood. 2 cords a month if I gotta go 24/7 with it. The temp swings would go from 72-60. Gotta leave the damper open because of the instant creosote.

Now I burn coal in it. No temp swings. Coal is a nice and steady burn. Load twice a day. No creosote.
House stays between 68-72. Yum Yum.

 

[jebatty]

Good information. To get a better handle on wood use, you might consider weighing the wood. Measuring in sticks, rounds or cords, while helpful, does not give a very good indication of heat (btu) content available due to variations in species, etc. On the other hand, weight of all wood at the same moisture content has about the same btu's per pound. Wood by volume varies widely in btu content.

 

[blades]

Most of the older style solid fuel furnaces were designed for coal- and you could burn wood in them. They are wood hogs to the max. Many out there yet that are the same basic design. Kuma & Caddy and a couple others are in step with modern technology designed with wood as the sole fuel source big difference. I have a hog down stairs as well, also good at producing creosote- moisture content of wood not with standing, never could get more than 4 hours of heat off it- never trusted it to not over fire and so on. That said it did cut the heating bill as was its purpose just such a pia. never use it now as I have a NC30 on the main floor which supplies 98% of my heat all winter, at 1/3 the consumption of fuel. 20 something outside- 73 in and I haven't reloaded from over night yet- just burnng down coals.

 

[JRHAWK9]

I thought about keeping record of the weight of each load as I know it's a much better way to do things, but my GF (and everybody in her family) already thinks I'm strange with my analytical personality.

What do you guys use to weigh wood?