Small things matter

[Joeboy]

House is at 14.1 degs this morning on Hive, unoccupied and no heating. Glad to have that as a reference.

[Fintray]

House is at 14.1 degs this morning on Hive, unoccupied and no heating. Glad to have that as a reference.

Really mild up here today, was at 14C this morning and still the same just now. See how it goes next week if the weather forecast is accurate!

[Joeboy]

House is at 14.1 degs this morning on Hive, unoccupied and no heating. Glad to have that as a reference.

Really mild up here today, was at 14C this morning and still the same just now. See how it goes next week if the weather forecast is accurate!

Snow apparently on its way next week? Cracking on with side two this morning while its mild.



Home from Edinburgh yesterday evening and fired up the WS. This morning big room is at 16.5 degs, no GCH. That's as good as an example as i think i'll find.

[Joeboy]

Just noticed that I have two shapes of bricks. Luckily the more awkward to cut (upper) is from my keeper collection of spare heaters. Would be a pig to cut through that thicker step with a 5" grinder.

[Joeboy]

This side is open so have taken a belts and braces approach with dabs of fire cement locking it together and to the WS. Quite excited as this is the first additional mass since I set up for test. A heady extra 15kgs added! I think I'll get a couple of Welsh roofing slates , shape and shim them out with a bed of fire cement to slightly extend the cooking surface A ways to go before that but should look quite nice.

[Joeboy]

Distinctly see the cut off at WS stand thermal blocks.

[Joeboy]

Well that went quicker than expected. Very happy with the look. The rear and underside to do and we're good.

I tried to induce a sense of visual order with some random to keep it interesting.

[Joeboy]

Financials- Gear bought for job have been a diamond cutter blade(£7) for the angle grinder and a 2 kg tub of fire cement(£4.50). All else has been free sourced or harvested from our garden.

Gas use at the house for Nov 2020 was 2,299kWh!

Woodstove went online around 16th Dec 20 so the next figures are a combination of the woodstove and the thermal mass.
To date in Nov 21 we have used 495kWh gas which put us on track for a sub 800kWh gas use for the month. A 1.5MWh improvement in gas use in a single month is mind blowing. I'm not even going to try and play it cool. I am over the moon!

At the moment we have 120kg's thermal mass installed as I'd like it to be and a further 45kg's in loose test mode. I think I will get up to around 220kg's in place in total all interlinked thru the fire cement. Somewhere around 8.5kWh thermal storage battery for £12. I repeat £12...

Sub £12 investment and I will know in Jan 22 the benefits of the thermal mass on its own as that will be the first full month I have when the wood stove was running for the full month previous year. I look forward to see the standalone figure for the thermal mass. At the moment it looks like WS&TM combined will save us £90 for this month.

Aesthetic test passed via SWMBO so far. Might start lower section tomorrow.

Page 1 photo for reference.

[AE-NMidlands]

I'm with BTB. you say the bricks surface "Only" gets up to 140 deg C. But when covered with the wood they are likely to get hotter as the wood is effectively insulating then. At around 180 deg C wood will start to "char", i.e. break down - I have just checked this with a hot air gun I use for repairs to electronics with Surface Mount Components. Part of the "charring" process is to start to give off volatile gasses - granted it is a one way process i.e. once the wood has given all it's got it can give no more, but at that temperature it will ignite so, so easily.

The term has just come back to me: pyrophoric carbon. Although it seems that there is now as much assertion that it does not happen as the old idea that it did!
When I was involved in fire investigations in the 1980s the (post-war) textbooks talked about this, and how even steam pipes in close proximity to (e.g.) timber beams could lead to their eventual ignition when you wouldn't otherwise expect it. They had examples from old UK mill buildings.
https://www.fireengineering.com/leaders ... fire/#gref says

Here’s what the NFPA “Fire Protection Handbook” says on the matter: “Wood in contact with steam pipes or similar constant temperature sources over a long period of time may undergo a chemical change resulting in the formation of charcoal which is capable of heating spontaneously. It has been suggested that 212° F is the highest temperature to which wood can be continually exposed without risk of ignition.” Furthermore, “Under certain conditions, charcoal reacts with air at a sufficient rate to cause the charcoal to heat spontaneously and ignite.”

There seems to have been little experimental work to verify just how high a temperature may be safe for extremely long periods of wood exposure. In one test, a 2-foot-thick stack of wood fiberboards ignited in 96 hours at 228° F. (Normal wood ignition temperature ranges from 380 to 500 degrees.) Other data shows that in 30 percent humidity, temperature of less than 150 degrees reduces wood’s normal moisture content to less than 5 percent.

Increasing problem

The formation of pyrophoric carbon through slow oxidation of wood has become of growing importance to the fire service recently because of the increasing number of unsafe, do-it-yourself space heating installations, such as wood stoves. Carbonization of adjacent structural parts takes place fairly quickly at high temperatures, however. When you see a stovepipe or chimney flue added to a residence, the potential danger is obvious. Where there is no such high temperature heat source, however, the problem may go unsuspected indefinitely.

but that is an old web-page, and maybe no longer held to be relevant - perhaps even by the people who published it.
I do know that a bit of charcoal in my bee smoker from the previous use can be brought to blaze if the smallest spark lands on it - much easier than lighting cold wood or cardboard.
A

[Joeboy]

I'm with BTB. you say the bricks surface "Only" gets up to 140 deg C. But when covered with the wood they are likely to get hotter as the wood is effectively insulating then. At around 180 deg C wood will start to "char", i.e. break down - I have just checked this with a hot air gun I use for repairs to electronics with Surface Mount Components. Part of the "charring" process is to start to give off volatile gasses - granted it is a one way process i.e. once the wood has given all it's got it can give no more, but at that temperature it will ignite so, so easily.

The term has just come back to me: pyrophoric carbon. Although it seems that there is now as much assertion that it does not happen as the old idea that it did!
When I was involved in fire investigations in the 1980s the (post-war) textbooks talked about this, and how even steam pipes in close proximity to (e.g.) timber beams could lead to their eventual ignition when you wouldn't otherwise expect it. They had examples from old UK mill buildings.
https://www.fireengineering.com/leaders ... fire/#gref says

Here’s what the NFPA “Fire Protection Handbook” says on the matter: “Wood in contact with steam pipes or similar constant temperature sources over a long period of time may undergo a chemical change resulting in the formation of charcoal which is capable of heating spontaneously. It has been suggested that 212° F is the highest temperature to which wood can be continually exposed without risk of ignition.” Furthermore, “Under certain conditions, charcoal reacts with air at a sufficient rate to cause the charcoal to heat spontaneously and ignite.”

There seems to have been little experimental work to verify just how high a temperature may be safe for extremely long periods of wood exposure. In one test, a 2-foot-thick stack of wood fiberboards ignited in 96 hours at 228° F. (Normal wood ignition temperature ranges from 380 to 500 degrees.) Other data shows that in 30 percent humidity, temperature of less than 150 degrees reduces wood’s normal moisture content to less than 5 percent.

Increasing problem

The formation of pyrophoric carbon through slow oxidation of wood has become of growing importance to the fire service recently because of the increasing number of unsafe, do-it-yourself space heating installations, such as wood stoves. Carbonization of adjacent structural parts takes place fairly quickly at high temperatures, however. When you see a stovepipe or chimney flue added to a residence, the potential danger is obvious. Where there is no such high temperature heat source, however, the problem may go unsuspected indefinitely.

but that is an old web-page, and maybe no longer held to be relevant - perhaps even by the people who published it.
I do know that a bit of charcoal in my bee smoker from the previous use can be brought to blaze if the smallest spark lands on it - much easier than lighting cold wood or cardboard.
A

Cheers, going to play it by ear. Will be keeping an eye on it.