Mini Stove > Cabin job.

[joe90]

I confer to those that know more than me…….

[zoothorn]

35 minutes ago, joe90 said:

Why not just add a flat plate above the pipe (to stop rain ) pop riveted on straps both sides 🤷‍♂️ Not as nice looking but cheap!

 

or https://www.ebay.co.uk/itm/401747290406?

Yup.. this idea would save me £30 (the hats actually £22 once you specify 150mm... the £3.95 figure is disingenuous).

 

So Im on the same page as you as it were. But would one of these fit my twin wall is the Q.

 

Thanks zoot.

[zoothorn]

Anyone know how a cowl fits onto a flue? @ProDave perhaps?

 

The general way sections fit to the next, it seems, is the upper one is slightly smaller sliping -within- the section below. I think the reasoning being ease of access to adding joint paste (I cannot think of another reason.. as if smoke rises, it would seem logical to me to have the lower section slipping within the upper.. but access to add paste is more difficult).

 

If this is the general rule, then the cowl also slips -within- the section below. But rain falling means this seems illogical. 
 

Thanks, zoot

 

 

 

 

[markc]

Depends on design, many cowls are on spring legs, some need a pilot hole and a self tapping screw

[saveasteading]

13 minutes ago, zoothorn said:

how a cowl fits onto a flue

I have fitted one, and it was made specifically to slip over the flue section. Therefore it only needed some fire mastic and pushed on.

[zoothorn]

11 minutes ago, saveasteading said:

I have fitted one, and it was made specifically to slip over the flue section. Therefore it only needed some fire mastic and pushed on.

Hi SAS.. thats useful thanks, & confirms my logic. So just need to check any other reason I cant get a cheapy 5" one.. & done.

 

Sorted chaps, thanks.

[zoothorn]

21 minutes ago, markc said:

Depends on design, many cowls are on spring legs, some need a pilot hole and a self tapping screw

Hmm.. Id better double check, but afaik it joins with a band/ clamp.

 

Ok Im ordering.. thanks. 
 

zoot.

[ProDave]

Flue pipes (in the UK at least) join with the upper section going down inside the lower section.  the reasoning is any condensation or tar will run down the inside of the flue.  There will be plenty of convection or draught to stop any theoretical combustion gas leak.

 

The cowl, as in the top cap or "China man's hat" on the top is made especially for the particular twin wall flue you have bought. It joins in just the same way as any other twin wall joint ensuring the top of the twin wall is covered so water cannot get down into the insulation.  TIP add some wire mesh or at least chicken wire around the gap between the top of the flue and the actual cowl.  It is worth the effort getting up onto the roof after TWICE dismantling the top of the stove to retreive the stupid bird that went down the flue.

 

The roof flashing fits differently. It slides over the flue. It does not clamp in the same way as a twin wall joint, it will probably have it's own joint clamp supplied with it.  Ours is 2 parts, a lead flashing that gets tiled into the roof, and then a stainless steel cover that clamps to the flue pipe immediately above the lead flashing as a second layer of protection to stop water running down the pipe.

[markc]

@zoothorn sorry I didn’t realise (read) you were using twin wall, I figured it was a simple ‘shed chimney’ needing a rain protector China mans hat (pretty sure you can’t call them that now)

[ProDave]

 

 

That's my flue just being installed showing the roof flashing and the rain deflector immediately above it, and the twin wall China Man's hat.  (what is wrong with calling it that?)

 

Note this was BEFORE i found the gap between the actual top of the flue and the hat was large enough for a stupid bird to enter so it is now covered with steel mesh.

[zoothorn]

@ProDave Aha got it. Now Im fully on board! Fancy that. After only 11 pages.

 

Boid protect wire is a good idea, I asked my builder to shove some in my house main cowl.. but never had thought to do on this. Very easy access just a step ladder hop/ up onto roof.. once my blackbird's fkd off & fledged that is. So cold today Id have put the bloomin stove on I think.

 

So I must then need a specific chinahat for my twin wall, the hat having an inner & outer pair of walls ( but without foam between) then these two fit down & slip over the twin wall, to cover -its- exposed foam.. it can only be. Then a clamp band. Finally got it!

 

If I hadn't established this I'd have wasted a fair bit of ££'s going my cheapy way. 

 

So £200 for the 4 pipe bits inc two band clamps, & including PeterW's Chimfit roof jobby = a £chunk, but could be worse.

 

Thanks. Zoot.

[saveasteading]

11 pages on, but as well as helping zoothorn's flue issues we have gone into diy hydro-electrics, torque, nesting birds and ...I can't remember now. 

Will the next question be as engaging?

[zoothorn]

54 minutes ago, saveasteading said:

11 pages on, but as well as helping zoothorn's flue issues we have gone into diy hydro-electrics, torque, nesting birds and ...I can't remember now. 

Will the next question be as engaging?

No.

 

But don't forget Tom Waits growling away too. Its got it all SAS. 

[Gus Potter]

On 14/04/2022 at 21:59, zoothorn said:

Stream can swell to max 3 ft or so of quite rampant flow,  eg after a 2 day deluge, making quite a racket akin to a waterfall.

 

Pic looking onward past cabin here ( 6ft on from back pillar is my boundary end). Pretty wild this bit, no mans land really.

 

Odd place to find two gooseberry bushes I thought ( @ pillar, another opposite bank).

 

zh

 

 

 

 

 

 

Great thread you have got going here @zoothorn

 

That stream / burn you have there. I wonder how much heat you could extract from that with a heat pump without damaging the wildlife.

 

I used to live out in the country and had something like that. On my wish list is to have a go at a DIY heat pump, just for a laugh using an old fridge compressor in reverse, a few controls to reverse flow to get the automatic defrosting.

 

Oh and make sure you install you flue the right way up all along the length.

 

 

[saveasteading]

57 minutes ago, Gus Potter said:

a heat pump

Great idea. A problem with GSHP is that the ground gets cold, unless there is a new source of heat, eg water flowing through gravel.

Zoothorn, You have a constant supply of new water. Any idea what temperature?

[Gus Potter]

1 hour ago, saveasteading said:

Great idea. A problem with GSHP is that the ground gets cold, unless there is a new source of heat, eg water flowing through gravel.

Zoothorn, You have a constant supply of new water. Any idea what temperature?

It does and your grass does not grow, also in my mind what is the point in saving energy if you chill the environment and thus inhibit the wildlife that we rely on. Could be the bees polinating the crops we all rely on for food, the insects that need warmth to thrive and the birds that feed on them. We should think carefully before we mass produce heat pumps and stifle the last bit / refuge for wildlife in our cities.. there could be unforseen consequences.

 

That said though the recoverable / easily recoverable energy density? in water is a lot more than air. @SteamyTea not strong enough on the technicalities of this? can you help?

 

@zoothorn the best place to recover heat would be just downstream of a neighbours septic tank.. just don't let on they are heating your cabin.

 

 

[Gus Potter]

On 19/04/2022 at 08:51, SteamyTea said:

This has been an ongoing debate in education.

Some educationalists think that courses should be developed to a more specialised areas i.e. Forensic Science, Renewable Energy, while others think a more general education is better i.e. mathematics, Physics.

This gets much harder with the arts and humanities i.e. painting or sculpting, early learning or phycology.

As part of my post grad in education, I had to observe a lesson in the art department, it was in textiles.  I pointed out that it was really engineering and technology, but the 4 students thought it as art and craft (incidentally I had 30 IT students when I was observed, and only 26 working PCs, that is a challenge, peer learning comes to ones rescue in that situation).

 

My view is that with the sciences the first year should be the basics, second year students split off into interest groups i.e. chemistry, software, botany.  Then the final year should be projects.

Take my first degree, we had I think, 6 or 7 subjects (we turned down vehicle electronics, but it was over 40 years ago), second degree I think it was 18 subjects in all, including my favourite, environmental economics (I can put a price on nature, it is easy with proper surveys), and philosophy (which at the time I thought was nonsense, but looking back, was useful, should have been in the first year). 

 

 

Everyone should be taught Thermodynamics, Laws of Motion, the SI units, Laws of Indices and Algebra, along with English (or whatever language in your country).

International Sign Language would be useful at primary school for a few years, it is the closest we have to a universal language (I am a BSL user, though out of practice now).

 

There should be a 'how to deal with OFSTEAD inspectors' as part of the PGCE, it is all that college managers seem to care about.  I have seen really good lecturers go to pieces and leave because of an over promoted, useless colleague, has been put in charge of internal inspections and totally missed the point of education.

This is a off topic but @SteamyTea makes some good points.

 

Also if you look at @zoothorn  posts, it's infectious, the sharing of knowledge, questioning and exploring. The enthusiasm of all is clear, everyone here is learning something, or just enjoying the collaborative thinking.

 

Turning now to what steamy has posted, yes OT but here are my thoughts and how this enriches BH.

 

As a bit of a back storey. I left school at 17, went to college and got an HND in Civil Engineering, worked for a few major construction companies and went self employed when I was about 22 -24 , a while ago. Built up a reasonable business as a building contractor and had a life change at 40. When I was a Contractor I always enjoyed the teaching side, bringing on the apprentices and making sure that everyone else was able to grow too. It was not easy and eventually..

 

Packed it all in 40 and went to University to study to be an SE. That with hind sight was probably the best decision I made...

 

I still remember my first week at uni at and sitting there thinking.. these lecturers are giving me two things: The basics; maths, how to write and communicate etc but most importantly the tools that I need to enable me to teach myself that will set me up for the rest of my life. I appreciated this as I was older, not many kids can see this, and they can't be expected to either. During my time at uni I was fortunate to be invited to participate in reseach as an undergraduate, I was able to bring my commercial experience to bear which clearly most kids don't have.. and off the back of that I got involved in the "educational" side of things also.. and that is why I'm interested in what steamy is saying, but I'm also fascinated about how folk learn on BH, why the mods do what they do with apparently little recognition.

 

Mods.. OBE coming your way?

 

Steamy to quote you "Some educationalists think that courses should be developed to a more specialised areas i.e. Forensic Science, Renewable Energy, while others think a more general education is better i.e. mathematics, Physics."

 

Steamy I agree with your view. One key for me in relation to tertiary education is that the educator.. you for example has to be skilled in the art and science of education and to be fully invested, in other words you need to be able for example to let the students see that you are enabling to teach themselves them not just delivering a lecture. Like all things in life if you can let folk see that you are doing something that is to their direct benefit then they will take notice. An educator of younger folk also need some good sales tactics!

 

That is the true skill of an educator. I know this works as I have been lucky enough to be taught by some expert educators and have been old enough to appreciate what is going on.

 

Now a skilled educator needs to be renumerated.. and recognised as a contributor to society.. we don't really appreciate this as much as we should in the UK. I could go on an on.. but

 

Turning back to BH. It's a great site for all. No matter what stage in the "things to do with houses" you are at. BH is a great resource.

 

That's it. but thanks again to @zoothornfor starting this thread

 

 

 

 

 

 

 

 

 

 

 

[SteamyTea]

5 hours ago, Gus Potter said:

That said though the recoverable / easily recoverable energy density? in water is a lot more than air. @SteamyTea not strong enough on the technicalities of this? can you help?

All down to the heat capacity, either volumetric or specific, by mass.

The Urban Heat Island affect has been blamed for damaging the local flora and fauna, but I have not seen any studies at smaller scale i.e. a domestic ASHP changing a garden.  But there are studies that look into the affects of combustion technologies at the street level, and other studies that look at combustion from larger thermal generation plants.

The main thing about renewable energy extraction is that it is very diffuse circa 2 to 4 W.m^-2.  That sort of extraction rate is usually lost in the noise of variation.

It really comes down to picking technologies that do the least damage, artificially compensating, or offsetting, environmental damage is a difficult problem i.e. changing a natural meadow to woodland, building a lake.

Conservationists have a lot to answer for as they are often trying to recreate something that never really existed, except in their minds.  There is a local project down here to get Cornwall's largest lake back to the condition it was in in 1935.  "So full of arsenic and tin, and in black and white" was my comment.  Did not go down well.  But then I was suggesting that a small water turbine be fitted (~0.5 MW) and the overall level increased, and boating being allowed.

[ProDave]

9 hours ago, Gus Potter said:

Great thread you have got going here @zoothorn

 

That stream / burn you have there. I wonder how much heat you could extract from that with a heat pump without damaging the wildlife.

 

I used to live out in the country and had something like that. On my wish list is to have a go at a DIY heat pump, just for a laugh using an old fridge compressor in reverse, a few controls to reverse flow to get the automatic defrosting.

 

Oh and make sure you install you flue the right way up all along the length.

 

 

I did briefly think about a water source heat pump from our burn, but to extract that much water (even if it goes straight back slightly chilled) would need an extraction licence and I could not face even attempting the paperwork to get permission.  One alternative might be a heat exchanger, aka an underwater radiator?

 

Our burn never freezes, even in winter it is flowing but with ice forming on the banks it can't be much above 0 so not a lot of headroom to extract energy from it or you will be pumping ice cubes back into it.

[SteamyTea]

9 minutes ago, ProDave said:

Our burn never freezes, even in winter it is flowing but with ice forming on the banks it can't be much above 0 so not a lot of headroom to extract energy from it or you will be pumping ice cubes back into it.

There is nothing special about 0°C, it is the temperature differences.  The kelvin scale should really be used, put it into proper perspective.  If you have a decent flow, dropping the local temperature 0.25K should not be a problem.  Would give you a 0.3 kWh for every m³ of water.  So a flow rate of 3m³.h^-1 will give you a power output of 0.9 kW.  And that is a very low flow rate.

 

But to keep it all real, solar down here has a mean power of 135 W.m^-2, probably 90 W.m^-2 up your way, and that is what is warming the water.

Edited April 22, 2022 by SteamyTea

[ProDave]

6 minutes ago, SteamyTea said:

There is nothing special about 0°C, it is the temperature differences.

Except if it enters your heat pump at 0.1 degrees and you reduce it's temperature by 0.2 degrees, it leaves in lumps which the heat exchanger and pipework probably won't like.  AND it would have to be flowing all the time, even if the heat pump was not operating otherwise it would freeze in the pipes and heat exchanger.

 

Zoot's stream may not get that cold, but in winter ours is snow melt, so barely above 0.

[SteamyTea]

13 minutes ago, ProDave said:

Except if it enters your heat pump at 0.1 degrees

Put a thermometer on it, probably high temperature.

[zoothorn]

@PeterW 
 

All flue bits here today including roof johnny (& my placcy wall boards via UPS.. like xmas day here!).
 

Now then your amazon roof rubber johnny.. can this be used on my angled roof? I thought the concertina part of it facilitated this.. but more rigid than expected, & isn't actually a concertina I find.

 

Thanks zoot.

[zoothorn]

Here's link again.. not certain it can do my sloped roof. But a bit ambiguous wording may suggest possible-?

 

https://www.amazon.co.uk/dp/B07VD9VCW2/ref=pe_27063361_485629781_TE_item

 

@PeterW

 

And my roof pitch again here.. Thx zoot .

 

 

[saveasteading]

7 hours ago, ProDave said:

One alternative might be a heat exchanger

The water will be cold long after the winter too. 

BUT is it not simpler to circulate a closed loop into the burn, and to use antifreeze in the loop?

Then instruct it to think in K not C and it will get energy out of the burn which will become just a tiny bit colder. How much energy though I leave to the experts on here.