Heat transfer efficiency -how good is it?

[smirnov3]

Last week we had a thread about how much money people save with stoves over furnaces. I think this information needs to go into the Wiki, but to do that, we need real data.

Since I have not been able to find anything on the internet, I would ask members to post the numbers from their own experiences.

what i need is:
1) how many BTUs of coal/wood/pellets did you use in your stove last year to heat your house.
2) how many BTUs of oil/gas/LP did you use in your central heat furnace previously
3) how does the central heat distrubute the heat? (ie gravity feed hot water, forced hot air, steam, etc)
4) are the central heat radiators / vents located next to exterior walls?
5) how well insulated is your basement?

 

[Rhone]

House= 1300 sq ft ranch
Insulation= R18 Attic, R6 walls, no basement/floor insulation and my basement is a walkout and unheated
System: Oil, forced hot water through baseboard exterior walls

2004 used 86mil btu's oil = 769 gallons
2005 used 45mil btu's wood (4 cords), 29 mil btu's oil (258 gallons) = 74 mil btu's. It was mild winter compared to previous

In the end, in 2005 I saved about $200 by burning wood, of course converting the 74 mil btu's into gallons of oil and not comparing it to the previous much colder year. This year I'm heading for around $350 if the variables were still the same, but for 2006 they've changed. I air sealed significantly, insulated my sill plates, replaced 3 leaky windows with Low-E Argon, and insulated my attic to R45, along with improvements to my install that will probably help my wood burning efficiency and I'm making a block-off plate that's far superior to my old one, my old wasn't long enough and not sealed. I no longer have an apples-apples comparison. If you get your own wood, and 4 cords isn't bad, would've saved more like $900 in 2005.

BTW I calculated my btu's based on 16,000,000 btu's/cord at 70% efficiency of unit and my oil btu's at 140,000 btu's/gallon at 80% efficiency.

 

[smirnov3]

Well, you seems to have a a good efficiency on your heat transfer (I'm assuming that temp inside the house was about the same, on average).

We'll see how my house compare next spring...

 

[BikeMedic2709]

I don't have specific numbers. (I will work on them.) I will say that 2 years ago I didn't use any wood heat. Strictly natural gas. My wife and I got a printout of usage and charges from our Natural Gas provider and we compared year to year. the savings was nearly $2000.

 

[webbie]

This type of comparison has so many variable that I don't see it going in the wiki. In fact, there are many cases where central heat does a better and more efficient job of heating than space heat.....depends on the area to heat and the layout - and the number of people in the house, etc. etc.

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I guessed that space heat can save from 0 to 50% over central heat - that is such a wide range that coming up with anything factual can be tough. We are also dealing with the "big fish" theory, etc. in that people who make large investments of time and money WILL save heat no matter what - the placebo effect.

 

[BikeMedic2709]

Very well put, Craig. I began attempting to figure out the BTU load of my home, and really got to thinking that my heating load is so dynamic. Especially with kids! Door open...Door Closed...Door open...Etc. Now that I have 2 children that have the ability to come and go, (outside to play in the snow or in-and-out of the AC house, to the pool) so this alone can increase the load exponentially. I try to look at the bottom line. $$$$

 

[Roospike]

I'll throw some very basic #'s up . We bought our house and it is 100+ years old and the inside is/was out of date. The house had 2 Warm morning gas 55k BTU heaters , 1 in the main part of the house and one in the add on back room ( they had a 55k btu gas stove in a 16'x16' room -duh ) Total inside remodel and took out the gas stoves as well. Installed the wood stove. We went from a gas bill of $190.-$260. in the winter to 100% wood heat. the only gas is the hot water heater an it runs around $26. per month. so i guess an average of $225. x 6 months = $1,350.oo per year. Now thats going from gas heat at 68° to wood heat at 74° . and also with gas prices from 2 years ago are figured before the price hike went way up. EDIT: I guess this information doesn't do much for the thread topic.