Supermarket Logs

We have three supermarkets next to each other who sell logs within easy distance.  namely ALDI, B&M, and Tesco.  I decided to compare their offering for firewood and do a practical test.

Aldi

Aldi sell "Wood logs" but don't say if they are hard or soft wood.  I bought 4 bags at £5 each and the weights varied between 4.4 and 5.2Kg.  The average was 4.73 Kg which gave a price of £1.06 per Kg

These seem to burn similarly to the B&M birch logs below.

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B&M

B&M sell Birch hardwood logs for £6 per bag.  Once again I bought 4 bags.  Weights ranged from 5.9 to 6.3Kg with a mean of 6.1Kg.
So average price is 98p per Kg.

Results
They start easily and burn well.  The air vent at the bottom needs to be completely closed to stop the logs burning too fast.  15 minutes after lighting there is obviously quite a bit of heat from the fire.

A softwood log (below) can be added but when a couple of fresh birch logs need to be added, after about 45-60 minutes, the softwood log will still not be burned out.

B&M also sell softwood logs for £5 per bag. Weights ranged from 5.2 to 6.9Kg (a big variation) and the mean was 6.15Kg giving a cost of 81p per Kg.

Results
They take a long time to get started.  The air vent at the bottom of the fire needs to be completely open.

30 minutes after lighting and not a lot of heat coming out.  

I finally had to add a couple of Aldi logs to get the fire to burn

Probably best to add to the fire once it is well away on some other logs.  By themselves they are pretty useless.  

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Tesco also sell bags which look similar to B&Ms birch bags but they cost £8 per bag.

Our local Log supplier is Logans logs.  To get the price down to around £1 per Kg I'd need to buy 20 bags of 30 litre. Or maybe a lorry load. Now the wood is sold by the cubic metre. but as it says on Logan site:-

Please Note: 1 Cubic Metre Loose does not equate to 1 Cubic Metre Stacked.

So what does it equate to?  Bags will have around the same volume as stacked, but with a lorry load, who knows.
We do not have a huge log store. I only just managed to store the 68Kg above.  So twenty 30 litre bags (or 200Kg) or a lorry load (whatever that weighs) is out of the question. So for us, it looks like supermarket kiln dried wood at around £5 or £6 per bag is the best buy

This page indicates that there is not a big difference in heat output between the different types of wood.It is around 4.5KWh per Kg. At £1 per Kg that means energy via logs is around  22p per KWh.  As the burner is around 70% efficient that means around 32p per KWh into the room.

Overall, B&M's birch logs seem the best option.  Aldi is cheaper per pack but the packs are smaller.

Heatlogs may be a little cheaper - an evaluation is needed.

By comparison, our current electricity costs 21.93p per KWh. Now electric heaters are 100% efficient that would be 22p/KWh into the room. 

Our gas costs 5.63 per KWh which is a lot cheaper.  The boiler is very efficient at around 95% but that heat has to come through under floor piping where is will lose some heat.  Also it heats up the entire house.  We have a thermostat in the living roombut the other rooms are controlled by fairly crude thermostatic controls on the radiators. We tend to have the thermostat set to 22C but when the outside temperature is in single figures we cannot get the living room temperature above 20C with the gas central heating alone.  To get the living room temperature higher using the gas alone I'd need to increase the radiator water temperature.    

I'll update this post as we burn some of our purchase.