Preparing for Winter V

zeupater

tori.k wrote: »

Mardatha or anyone who uses coal as their heating, can I please pick your brain
We moved on to coal as the wood wasn't heating the place enough, been lovely to be able to keep the fire in overnight and keeping an ambient temperature of around 20c fire is set to it's lowest setting just ticking away, we have a 9.2 kw stove using around 8-10kg of smokeless coal a day, ( £5) does this sound about right.
First time I've used coal so have no idea what I'm doing

Hi

We don't use coal, but a good proportion of our heating is provided by burning logs (8kW high efficiency burner), so I'm surprised that your logs aren't giving out enough heat ... what kind of wood were you burning (hard/soft?) & was it fully seasoned and stored undercover? ...

10kg of logs in a reasonably efficient burner should provide around 40kWh.t and the same weight of a decent smokeless coal around double (so~ 80kWh.t) ... at prices around here, bulk hardwood logs cost around the same per kWh.t as smokeless coal but is far more emissions/climate friendly.

As an aside, if 8-10kg of smokeless coal is costing £5, you're paying at least a 50% premium over what you could be buying the fuel for!

HTH
Z

tori.k

zeupater wrote: »

Hi

We don't use coal, but a good proportion of our heating is provided by burning logs (8kW high efficiency burner), so I'm surprised that your logs aren't giving out enough heat ... what kind of wood were you burning (hard/soft?) & was it fully seasoned and stored undercover? ...

10kg of logs in a reasonably efficient burner should provide around 40kWh.t and the same weight of a decent smokeless coal around double (so~ 80kWh.t) ... at prices around here, bulk hardwood logs cost around the same per kWh.t as smokeless coal but is far more emissions/climate friendly.

As an aside, if 8-10kg of smokeless coal is costing £5, you're paying at least a 50% premium over what you could be buying the fuel for!

HTH
Z

It's due to a mix of working hours and solid stone walls, the burner is our only source of heating and we couldn't keep the fire in long enough to put enough heat into the walls so couldn't get the temperature above 14-15c running seasoned hardwood, the coal is allowing us to keep the fire ticking over . We've been getting the coal for just over £9 a 20kg bag of taybright with delivery the coal man suggest it because we are out so much and it's easy to keep in, but we do seem to be going through it fast, up to this year we've always seasoned our own wood so don't really have a reference cost wise for heating.

mardatha

tori we use smokeless eggs, at £18 a bag. I dono how much the bag weighs but it's a full sized sack from the coalman. We go through 2 a week, topping the fire up in the morning then emptying the ash and filling right up at teatime. We keep it at 0 on the wee dial at the side. That heats my stone walls, logs or wood or peat never did. Also gives us enough hot water for 3 baths a day if we want.

mardatha

Get a bag of anthracite and put some of that on overnight, it damps the fire down and keeps it smouldering until morning, when you poke it up and put some coal on. Lots of people here mix coal and logs to save money, at weekends you could maybe use up some of the logs. Husband is low thyroid and heart probs and he feels the cold, so it matters a lot to us to stay warm and cosy - livingroom is a constant 24/26C. I hope this all helps you pet x

zeupater

tori.k wrote: »

It's due to a mix of working hours and solid stone walls, the burner is our only source of heating and we couldn't keep the fire in long enough to put enough heat into the walls so couldn't get the temperature above 14-15c running seasoned hardwood, the coal is allowing us to keep the fire ticking over . We've been getting the coal for just over £9 a 20kg bag of taybright with delivery the coal man suggest it because we are out so much and it's easy to keep in, but we do seem to be going through it fast, up to this year we've always seasoned our own wood so don't really have a reference cost wise for heating.

Hi

With solid stone walls you'll have a thermal mass issue regardless of whether you have insulation, or not .... but the best way of keeping warm at an affordable price is to insulate, insulate & when you think you've done enough ... insulate some more (of course, if possible!)

We're well insulated (cavity, loft etc), but there's plenty of solid internal & external walls to soak up the heat. When there's heat in the walls we don't need to have a fire every day if it's not too cold outside, but if we don't 'top-up' the heat in the walls on a regular basis it takes a massive amount of energy to build the heat back to where it was, normally taking days on end!

On keeping the fire going overnight .. if necessary we can keep the stove ticking over for 8-10 hours between refuelling by using really large & dense hardwood logs which we keep to one side for that very purpose - the next morning it's just a case of dropping some small logs into the fire & opening up the airflow ... 10-15 minutes later the skin temperature of the burner is back up to ~500F. Sometimes the bed has cooled more than normal, so some screwed-up newspaper is thrown in with the logs, but it's normally burning before you can close the door!

Regarding £9/bag for smokeless coal - that's £450/tonne! - are you buying small loads or moneysaving by having 1tonne pallets of bags delivered at a time? .. I would have thought that pallet deliveries would save you 25-30%/kWh.t if you have available space & finances.

On the point of a heating cost-reference, that'll really be down to the combination of your property, how well it's insulated, the heating pattern & (importantly) the temperature you're comfortable in, so it's pretty hard to judge, however, government figures suggest that the average home uses around (from memory) 3300kWh of electricity & 15-18000kWh of heat/DHW from gas (/other sources), but at the extreme end of efficiency there's 'passivhaus' requirements which are based on really low heating requirements per square meter of living space, but this can normally only be achieved in new build properties ...

A few posts ago I referenced an interesting blog entry on a site in which someone has achieved quite amazing levels of energy efficiency which is probably possible to replicate in a good proportion of UK homes - Winter's arrived in an energy efficient home - other entries for Autumn, Electricity & Gas consumption would provide an idea of what's possible as a target too, worthwhile having a look if/when you have time ...

HTH & keep warm!
Z

tori.k

Insulation is the problem this place is actually designed as a holiday let, we are in the process of moving and foolishly thought we'd be in the new house by now so ran out the wood, this is an unusual conversion the granite holds the heat well if you can get the heat into start with,
I've never managed to keep a wood fire in overnight no matter how many times I've tried we don't have the greatest of stoves a harmony H33 but it does the job and big enough for me to run a kettle or stew pot on.
Sounds like what I'm using is about right with coal thanks mardatha and thank you for the link Z as we are making our last house as sustainable and passive as possible. with having do a fair bit of work and move the oil tank to meet the new regs and replacing the old boiler seems a good time to update the whole system to see us through our old age.
Thanks again

mardatha

Tori I've googled your coal and it looks like the wee eggs. Ask the coalman for the bigger eggs, I forget the name of the stuff we get. They last longer and are slightly cheaper. We tried the wee ones and in the morning the fire was nearly out, so we went back to the bigger stuff.

[Deleted User]

5 degrees out there today and luckily no wind to speak of so not as cold as of late however we are due to get much colder over the next week as is the rest of the country so I've checked in the freezer and have a big bag of YS stewing steak in there and have bought some suet today at the farm shop and next weeks menu will involve a lovely big stew and dumplings to keep us fuelled and warm in the cold snap, a bowl of piping hot stew on a tray in front of the wood stove is a comforting supper in January and guaranteed to warm you through and make you sleep well too!

mardatha

Oh that does sound nice! I love dumplings, not seen one in years. We're forecast snow and gales here for Tues/Wed and we have the hospital on Wed, RV has to be in for 8am so I hope we get down ok. Gales for today as well, wind starting to pick up now but at least we saw some sun today and I even walked round the garden tidying up

zeupater

mardatha wrote: »

Tori I've googled your coal and it looks like the wee eggs. Ask the coalman for the bigger eggs, I forget the name of the stuff we get. They last longer and are slightly cheaper. We tried the wee ones and in the morning the fire was nearly out, so we went back to the bigger stuff.

Hi

That makes sense ... the time it takes to fully combust relates to the surface area in combustion to volume(/weight) ratio combined with the oxygen availability at any one time ... small logs will burn down more quickly than large ones, that's why we keep the largest & densest (burr wood from root etc) logs aside for 'keeping the fire in' overnight when we want to ...

HTH
Z