any of you clever folk worked out how much wood you burn on a 5 kw fire ? Keeping it about 380 c burning mostly free ash at minute . Been working on my wood piles for five month but it's only what I can get for free. Can get some idea of how far in front I can get . Pic is my second wood stack and using your guid it's 2.6 cubic yards
I think it would be hard to say based on the info. I googled kilowatt/hr, and apparently there are 3,412 btu's in one kwh. Are you saying your stove puts out a little over 17,000 btu per hour? Can you find one of those home heat use/ loss or energy use tables? Can you find the heat degree days of your location? What wood type (to find how many btu/per cord)? What brand of stove?
I'd pretend to step in as the Thermodynamic engineer here. There are so many variables in your home envelope that affect the performance of the what the actual stove is designed for. Add in draft, wood heat content, moisture content an what not - you are opening a massive can of calculus that needs not be breached. Cut, split, stack & cover your wood for 2-3years depending on species hardwoods like oak & hickory need 2-3yrs for optimal performance in modern stoves, softer woods pine, poplars or whatever you have across the pond may burn better in a 1-2yr seasoning period you can burn water - in a gas turbine fired at 2400F+ but asking wood to @300C/572F to provide complete combustion with limited airflow and high moisture content is going to be a grudge match
Thanks I'd better just keep collecting and stacking . Sounds way way out of my league to work any of them out. I were kind of hoping for a rule of thumb but looks like it's a lot more technical than I thought
I have been at it for 12 years and I still don't know how much I burn! What I can tell you is that this year I only burned 7 IBC's full of stacked very well seasoned mix of wood collected from tree removals and pruning. Sent from my iPhone using Tapatalk
Hi I am not to far away from you in Gourock on the Clyde, used to work down your way for a while I really enjoyed it and met some nice people. I have a 10Kw stove and from your picture I would be lucky burning every night for that to last me 2 months. As stated by the other guys there is a lot of variables. Just keep collecting as much wood as you can, you never have enough.
For a rough idea, do you guys have milk crates? Or the ability to build yourself a 12 inch by 12 inch by 12 inch box? Milk crates around here are that size, and if you pack it full of 16" wood, it ends up being 1.25 cubic foot (in a perfect world with no air space) or just call it 1 cubic foot to account for air space. There's 128 cubic feet in a cord. It will probably be a chore, but by doing so, you'll have a rough estimate.
I agree with Basod to some extent. Simplistically you could complete an indicative analysis, using how many cords of a certain species you used over a period of time, vs the ambient temperatures, and maybe the average temperature in your house. Maybe plot that data each week or day over the next 3 or 4 months and develop some trends. From there might be able to refine the calculations based on wood type to accommodate for known BTU's vs output, moisture content, etc. Someone mentioned the stove model, which is helpful as it should lead you to an efficiency number. This number likely will be overstated by the manufacturer so keep that in mind. If you are burning just ash, there are 21.6 Million BTU's (MMBTU) per cord. I can make a simple excel model for you, or maybe you just track it for a while and see what you use. You do not need to make this into a huge effort as you are not designing an industrial boiler, or any process which has a guaranteed energy balance. Leave a notebook near the stove and record simple data. Cords used, ambient temperatures, chimney temperature, house temperature at a fixed location, moisture content etc. Once you throw that data into a chart or graph, you likely will figure out what works and what doesnt, what you are using, and how to plan ahead. If you get stuck with the excel, there are several of us that can throw a spreadsheet together in two minutes that will work. Good luck
Thanks for that folks . Obviously my aim is to build up a decent sized store of wood . But my worst fear is I have to BUY it been from Yorkshire that just can't happen . Just finished work so it's out in garden to chop last nights haul up
It looks like you are working with just about 2/3 cord of not so dry wood, since it was collected this year. Even ash will benefit from a decent time to dry. If you choose to burn it this year I would suggest only using it on the coldest days to hold down how much other fuel you are using.
I started using a very rudimentary and non-scientific approach to wood usage this past year to help plan my wood cutting needs. I don't measure or guess cords at all. I measure wood based on utility trailer loads as I process it for seasoning. I also started keeping track of each trailer load I bring home to burn on a spreadsheet. I'm hoping this simple method will be useful.
Iv collected and split it this year but it's been felled for almost two . It's between 18 and thirty on my meter
Welcome Grahamt! Lots of good info on the site for all woodburners. Your question is one that comes up often here, and as many have already stated, there are simply too many variables involved here to give any kind of accurate measurment. That's why we here at FHC preach the "3 Year Plan". It's a plan that basically gets you three years ahead on Yiur wood storage, yes it takes a lot of work and time to do it but once you get that three years worth, all you ever have to do is collect one years worth each season thereafter. Use this upcoming season to educate yourself on how much wood you will most likely be using, but keep collecting as much as you can take in. Get it C/S/S (cut/split/stacked) quickly so it can start seasoning. I've been heating with wood for years now, and even my wood usage can be hard to predict. Some Pennsylvania winters are mild, some are quite nasty. I have two appliances, heating 2800 sq.ft, and I can go through anywhere from 5 cord in a mild winter to 8 cord on a nasty winter. At any rate, you'll enjoy our family here and I'm sure you'll learn alot, glad to have you from across the pond!
That definitely is a bit high. Also be sure you are using the MM correctly and measuring it immediately after the wood is split. It will also help if the wood is not too cold when measuring. But if you get on the 3 year plan, you can take the batteries out of the MM as you won't have to be checking the wood as it will be ready.
