Heat Logs vs coal

[Osbourne One-Nil]

As you may know, I heat my home with solid fuel via a multi-fuel stove, and it works a treat. The only problem is getting hold of enough top-quality hardwood logs to keep me going. In the past I've topped this up with smokeless fuel which is very hot and long-lasting but makes an horrendous mess and is surprisingly difficult to light.

Earlier in the spring I tried out some of these heat logs, and they're really really good. They seem to last, weight for weight, as long as smokeless fuel does, with the advantage of producing almost no ash (so no emptying) and that which it does produce can go straight onto the compost heap. Now, being really really anal, I'm tryign to work out accurately their heat output compared to smokeless fuel. I know the heat logs have a calorific value of 4.7MWh/ton, but how the hell do I compare this to coal-based stuff, which I've found a figure of 31GJ per tonne?

Can anyone help?

[Shiny_Bottom_1]

Does this help?

http://www.unitconversion.org/unit_convert...iency-mass.html

[Roo]

Haven't a clue how you compare, but I know mum and dad reckon smokeless fuel is horrible stuff (I think it cakes the chimney badly), and have recently bought an Esse stove (great product, awful customer service) so they can burn wood only.

[Osbourne One-Nil]

Smokeless coal is truly awful stuff. The amount of energy which goes into making it is enormous I think, and apparently it's packed with cement (or something like it) which results in almost 100% ash. It's messy and heavy but it does burn for a long time and slumber nicely overnight. I do think it's pretty good for the chimney though and loads better than all but the most seasoned wood, but I could be wrong. The heatlogs are chemical free, and as the brochure says, the CO2 released goes on to be re-absorbed by plants. I'm pretty sure the CO2 released from fossil fuels goes on to poison baby orphans in the 3rd world.

Does this help?

http://www.unitconversion.org/unit_convert...iency-mass.html

Come on - I need one with GJ. Try harder please.

[Shiny_Bottom_1]

Yes Sir...

http://www.cleavebooks.co.uk/scol/ccenrgy.htm

[Osbourne One-Nil]

Oh, right, I'll do the sum myself shall I?

It seems 4.7megawatt hours equates to 16.9 gigajoules, which is slightly over half the value I've found for coal. That therefore means that I shall now have to find a website which gives a much lower calorific value for coal so it fits my choice.

[Shiny_Bottom_1]

Of course. But I would like to see your workings written down with your answer, or i'll not be able to tell you if youve down it correctly or not.

[Osbourne One-Nil]

Now, this is truly fascinating. I have, from the manufacturer, a value of 389.3kWh/50kg of smokeless fuel. Therefore, that equates to 7786kWh/tonne or 7.79Mwh/tonne. Compared to the heat logs' output of 4.7mWh/ton, it's not so bad....especially when I pretend my house was a bit too hot with the smokeless fuel anyway.

[Tucco]

Gas 0.011 MWh/m3

Oil 9.96 MWh/m3

Coal 7.56 MWh/ton

Lignite 2.43 MWh/ton

Peat (50 per cent dry substance) 2.58 MWh/ton

Biofuels (chips, 40 per cent dry substance) 2.33 MWh/ton

Mark

Teesdale,Co Durham

[Shiny_Bottom_1]

I'm sure Peat Tatum would be happy with that figure.

[Osbourne One-Nil]

Thank you Tucco, good to see you enjoying this riveting topic as much as I am!

Now, costings. 50kg of Homefire costs £16.50 and gives off 390kWh or 4.23p/kWh. 50kg of heatlogs costs £15 and give off 235kWh or 6.38p/kWh.

Interesting that what is essentially a waste product can cost more than something dug out of the ground by northerners and processed heavily.

[Shiny_Bottom_1]

Doesnt seem much in pence, but ~50% more for the logs. I guess it depends on your total annual spend, and whether you are happy with the extra expenditure. If I could afford it, I would probably go the later if it is greener and cleaner/easy for your own use.

[Tucco]

Thank you Tucco, good to see you enjoying this riveting topic as much as I am!

Now, costings. 50kg of Homefire costs £16.50 and gives off 390kWh or 4.23p/kWh. 50kg of heatlogs costs £15 and give off 235kWh or 6.38p/kWh.

Interesting.

http://www.historia-energia.com/ing/conver...mp;idUnidadeB=8

This link converts varies fuels in mw/h.

Having a stove with back boiler fitted in the next few weeks so I'am interested in those heatlogs. Have an open fire at present with central heating running off oil.

Mark

Teesdale,Co Durham

Edited June 16, 2008 by Tucco

[Osbourne One-Nil]

The massive benefit the heatlogs have over smokeless fuel (aside from environmental ones) are they are quick to light without kindling (smokeless fuel takes for ever) which means I won't really have to run a fire overnight because I can light one and have it hot within minutes. With smokeless, you have to keep it ticking over all night really, so you use more fuel. Also, the amount of ash they create is almost nil, and that which it does leave behind can just stay put as for wood, you want to burn it on a bed of ash. The amount of ash from smokeless fuel is immense and HAS to be emptied at least once a day otherwise you'll ruin your grate. Carry out hot ash-pans in the dark on a morning isn't my idea of fun.

[0000]

i got a hot log going cheap

[Hairy Celt]

this kinda fizzled out... cheapest and best fuel is fast grown conifers cos it's usually free (you steal it from plantations) and cos it's so fast grown it dries out real quick - 18 ,monthss. only snag i have is that it takes a lot of storage space and handling.