openspaceman

There may be good reasons for going room sealed, one of them may be that the house is designed to be nearly airtight with very low infiltration rates with a whole house ventilation system managing the air changes. This could affect the operation of a stove when the pressure in the house changes. After all we are only talking about fractions of an inch water gauge between the stove and the top of the chimney, this is what drives the air through a natural draught (i.e. no fans) stove. As I tried to point out earlier in the thread the actual air flow through a small stove is likely to be a small part of the air changes needed in a house for a healthy atmosphere. Typically a stove will take ambient air from a room at about 20C raise it to about 800C to ensure a clean burn and exhausting it up the flue at about 200C, the idea being that it leaves the top of the chimney at above 100C to avoid condensation in the chimney. Heat losses due to dumping 20m3/hour of air with a delta C of 80 to 180 is in the order of 1kW and is not significantly different for room sealed or normal stoves. A gas boiler has much lower losses. @Retired Climber gets my point that increased air density leading to increased massflow is a consideration for a heat engine but not for a simple stove.

Doh, so you have to heat it up in the fire before dumping it out of the top of the chimney with greater heat loss than if you took air from the room that was to be made up from outside air anyway.

No but it would give more leeway to dry stuff in the summer and extra dry storage in the winter but if it's not in DNP remit to aid local businesses...

I suppose the change in the law won't cut much ice with your planners over erecting a polytunnel?

That's two of us then, it's a strange thing though that the whole of the insurance industry stems from it, my pension provider gambles that I won't survive five more years.

I wonder how the efficiency compares, my guess is you lose 30% of your effort straight away in the pumping losses.

There is a little hope in the fact ash were generally self seeded into hedges and woodlands, hence there could be a pool of resistant genes. I noticed an apparently unaffected mature tree in an otherwise devastated woodland, the owners have reported it on Report a Tree - Living Ash Project LIVINGASHPROJECT.ORG.UK Welcome to the Report A Tree Page Together, we can combat ash dieback through harnessing the natural genetic diversity... I advocated removal of all badly affected tree but apparently FC and NE do not agree. My thought was any promising progeny of these resistant trees would be overcome by the sheer amount of spores blowing about even if they could become resistant over time with a mature canopy.

That wouldn't surprise me and may be the reason soot has fallen and built up on the register plate, Probably , MEWP would be cheapest . I don't have a cowl but do think they are advisable because with a stove there is negligible airflow when the stove is off to dry out rain and a mixture of rainwater and sooty deposits is acidic and that percolating through cement is not good, my flue is cement cast in situ. I would love to have easy access to my chimney as not only would I sweep from there downward but I would also go to some effort to make a DIY electrostatic particulate filter to sit at the chimney top.

Ah I see, so the liner doesn't extend all the way through the register plate to the cowl or top?

Yeh, difficult one in this day and age but I would take out any baffles in the way and pass the rods and rotary brush up through the stove until they come out the top, if there are no obstructions the chances are an old single skinned sectional flue pipe is still okay. I imagine setting a proper register plate and fitting a 904 liner (8"/200mm??) will cost a couple of grand plus fitting a cowl. The thing is it's well out of time limitations for building regulations but no registered sweep is likely to risk passing it off, even with a pressure check.

I'm glad you took the plunge and hope things go well. I'd never heard of them till @agg221 mentioned them.

Yes, look at this one, the nearest ring is badly worn as shown by the wide gap, the one underneath near the top of the cylinder is the new one with the smaller gap. @adw is most likely right and the very hard but thin nikasil layer has worn through. This rarely happens with chainsaws but disc cutters work in a much dustier environment and I have no experience with them.

seeing as you have got the ring offer it up to the cylinder and square it in the bore with the piston and using feeler gauges check the gap in various places.

Yes, my home is by no means damp, I live in one of the driest regions in UK, going room sealed is probably the only way around the regulations with a bigger stove but drawing air from the room and a whole house heat exchanger makes more sense to me. The solid wall brick built with lime mortar eveolved over a long time, the walls need to breathe both sides so I am loathe to attempt insulating them, inside or out. I do wonder what effect wall hangings have as you see them in colder places of eastern europe. Modern build methods, done correctly which is the exception, may be the way to go to satisfy people sitting on the M25 but knocking down a 160 year old house and starting again is not an option.

Yes It looks like it has never been repointed on the exposed brickwork but the hall is a single storey extension from 1959, still solid 9" but rendered.

72% RH in my hall now and it has been a dry warm day after previous rain., so a fair amount of moisture in the air increasing RH as it cools to 9C outside. Once the stove is lit it will hover around 40% RH when the temperature differential gets above 10C

I live in a fairly basic draughty house but do have modern double glazing that seems to seal well but some of the windows have vents and bedroom windows generally have a top pane at least slightly ajar all the time. I have a nominally 4-5kW stove drawing air from the room. Air changes per hour differ between rooms but ~ 7 changes per hour recommended for a living room. This little room is about 3m by 4m by 2.4m so needs about 200m3 of air per hour. To get 4kW of heat, excluding flue gas losses I need to burn about a kilo of 20% mc wwb wood per hour. The stoichiometric air required (to react perfectly with that amount of fuel) is 6kg or about 10m3 of air from the room, in practice most stoves will supply 150% to 200% stoichiometric air, say 20m3/hour.

I am much the same

I'm not too sure about this because I think you could bend the crank on an original 262 by pulling it when it's been jammed in the cut, and not snapping the chain, later ones which could take the 3/8 chain had a stronger crank. It's an old memory so @adw may remember better. A chain run out of oil gets very tight, there was a recent post about a makita that had to have a new sleeve put in the crankcase because the bearing housing was oval and I asked if that ovalness came from it being yanked hard.

but did you measure anything, like the ring gap at various parts of the bore. Air has to be escaping somewhere for that low pressure figure.

Not really but I wouldn't like to lose the ability to only see unread posts initially

Well actually some of us didn't initially , and I'm talking well before FISA, but the association was usurped by the wrong people at the top who essentially sold out to the industry knobs.

Yes I believe so and it was perpetrated by the bigger industry moguls with the collusion of the FC in order to prevent small players challenging the status quo.

Yodel delivered a battery to me a 055 from numberone batteries, filled, but it did have transit plugs in.

Yup