how to calculate req'd size of woodstove

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how to calculate req'd size of woodstove

Post: # 257861Post Furoner
Wed Apr 04, 2012 8:16 pm

Has anyone suggestions where I can find how to calculate/estimate the required output of a woodstove given certain parameters e.g climate, house construction, volume, area of external walls, areas of d/glazed windows, other heat sources.....etc. If you have been through this exercise and will share experience then I'll let you have more details. Thanks in anticipation.

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Re: how to calculate req'd size of woodstove

Post: # 257873Post KathyLauren
Wed Apr 04, 2012 10:03 pm

To be honest, calculating seems like a lot of work, given the number of variables. Don't forget that placement of the stove and methods of circulating the heat factor into it too.

I would just visit around friends or neighbours that have wood stoves to see what works in houses like yours.

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Re: how to calculate req'd size of woodstove

Post: # 257881Post demi
Thu Apr 05, 2012 7:06 am

we calculate ours by how many square meters of space you need to heat, the more wood the stove can burn at one time the more space it will heat.
but yes there are many other variables.

we have a stove in the kitchen/living-room and another in the bedroom ( and others in the other bedrooms when there finished ) 1 is not enough for our entire house, but it certainly keeps the room its in nice and tostie :iconbiggrin:
Last edited by demi on Thu Apr 05, 2012 1:48 pm, edited 1 time in total.
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Re: how to calculate req'd size of woodstove

Post: # 257887Post bonniethomas06
Thu Apr 05, 2012 8:35 am

Hi there and welcome to ish :wave:

We have a 7.5kw stove which heats our titchy living room (3.5m x 4m) to sweltering point. Admittedly we are not good at keeping it on a low burn. So I recon you could get away with a 7.5kw in a 5x5m room with no problems.
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Re: how to calculate req'd size of woodstove

Post: # 257905Post niknik
Thu Apr 05, 2012 10:53 am

better too big than too small.!

Mine threw out far too much heat, for the room it was in........ so we took the wall out to the adjoining room :iconbiggrin:

by having it on full blast, and leaving various doors open, I can warm quite a bit of the house..... just cant sit near it though!

after a while, ( trial and error), you´ll work out what and how much to burn at any time to regulate the output

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Re: how to calculate req'd size of woodstove

Post: # 257922Post Zech
Thu Apr 05, 2012 1:39 pm

Yes we have been through this recently, and there are lots of online sites for the kind of calculations you mention. Unfortunately, when I looked through my bookmarks to find them, the only one I could find was this: which I seem to remember has an annoying limitation of hot water flow rates. You don't mention whether you want your stove to heat the entire house (our is running the central heating) or just one room.

What we actually did in the end was notice an old stove on the pavement outside the local hotel, had a look at the space it had been heating, reckon it was about the same as our house, and negotiate removal of said stove.

I'm not sure about the 'better too big' advice. Wood burns more efficiently when the fire's really roaring, so a small stove going flat out, with back up for the coldest few weeks of the year, is probably the most efficient way of doing it. It also means you can sit by the fire comfortably :iconbiggrin:

One detail we paid too little attention to was the effect of fuel type - our stove is multifuel but we only burn wood in it, which reduces the heat output to roughly half, we're told. Even so, we manage to get enough heat out of it.

I'd recommend the green building forum - - for technical advice, though it can get very technical :scratch:

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