johnnyone

[QUOTE=bil;9434283]So I'm right, and all the calls for a breatheable paint are shite, because the breatheable paint will make it worse. Plus, a plastic paint will either stop the problem or make it less bad.

No you are not right you just think you are.

bil

It's a great idea, but as I say positioning will take a chunk. Imagine a horizontal tube bed on the equator. At sunrise and sunset, you will get heat ONLY on the equivalent of the diameter of the tube on that side.

Then over the course of the morning that amount will increase until at midday precisely the whole bed will be operating at 100%. It then decreases.

So if we are using 10 tubes all of, say, 3 inches diam, then you will get three inches at sunrise and sunset, 30 at midday, so you will be getting a little more than 15, on average. In other words to get an average of 1 sq metre, you need two.

What's the KWH per sq metre at midday?

bil

[QUOTE=johnnyone;9434532] Excellent. Prove it please.

Oh yeah, I mean PROOF, demonstrable concepts rather than repeating the old mantra.

bil

Lemmee help.

1. The wall wicks up water.
2. The water contains salt.
3. As the water evaporates it leaves salt behind.
4. If the wall dries out, salt crystals form.
5. These crystals expand as they grow.
6. This pushes apart the plasterwork so that it crumbles.
7. A breatheable paint will not stop this process, it will facilitate it.
8. To stop this process we need to stop the flow of water.
9. We cannot easily block the flow at source with a damp course.
10. Tanking walls is a recognised way of curing such problems.
11. Plastic paint is equivalent to a thin tanking layer.
12. The water in the wall is not under pressure. It is sucked up.


So, taking all that into consideration, if you prepare the wall properly, and seal it with a plasticised paint, what will happen?

1. The water will wick up into the wall until it is in equilibrium.
2. The salts will dissolve and stay in solution.
3. This will prevent any further spalling.

What can go wrong?

1. If the paint is breached, then water will be able to evaporate out.
2. This will create localised spalling leading to the 'dustification' of the
plaster immediatly behind that point.

This is precisely what Tony describes.

So, we'll allow you the courtesy that your previous post was based on sound knowledge where you will be able to defeat one or more of the points I have made above.

You can do that, can't you?

lyric030250

The Frigiliana weather station (amateur) generally paks at about 925 w per sqm as it has today (full sun)

johnnyone

[QUOTE=bil;9434544] Bil plastic paint does not stick to damp walls. Perhaps you have been using permeable paint all this time without realising it.

bil

Call it a kilo then per hour. To get an average of a kilo an hour two sq metres, plus you have to allow for the fact that you don't get 100% conversion. 12 hours a day, call it 10 to allow for other bits, and two sw metres will grab you about 10 kilowatt hours.

A 2K kettle boils a litre in 3 mins, so a 1K would take 6, that's 10 litres an hour. So by my reckoning, 2sq metre would give 100 litres of boiling water a day.

That about right? or have my dismal maths let me down again?

bil

[QUOTE=johnnyone;9434597] No man, it say plasticised on de tin! Of course, I cheat by painting when the weather is dry. I find painting wet walls dam' tedious, don't you?

So, am I right? Can you break the chain of logic, or were you basing your comment on the fact that you thought me dumb enough to paint in the rain?



PS, does breatheable paint stick to wet walls?

lyric030250

When the weather is halfway decent my 2sq panel gets the water too hot to use.

tony

OH NO NOT THE PAINT AGAIN !!!

MY 160 litre swh can bring the water to boliing on a sunny day ( I have a video on you tube )

so if you think of that in terms of boiling a 2 l kettle you would have to put it on 80 times !!!! how much electric would that use day arter day !!

IT SAVES LOADS OF ENERGY !!

ANYWAY BACK TO PAINT

I have got a load of old car engine oil if i mix it with diesel do you think it would be any good to paint my timber fence with ??

tony

hi LYRIC

if your solar hot water gets to hot you could fit a thermostatic mixing valve

Regards Tony

bil

It would make it pretty flammable.......

Actually, it's what it will save that's interesting. I reckon 20 to 30 euros a month is hot water spend? That's showering, washing, washing up.

So for systems of 2 grand, that's a payback of less than 10 years, which is not bad.

tony

Yes the fence would be flamable but I think it would stop the rot and bugs.
The spanish use diesel quite alot to treat old wood.

Yes solar water heating saves alot of money, I fitted one on my mother in laws house 2 years ago and her electric bills are almost half now.

2 GRAND IS EXPENSIVE, I am sure you could fit a unit your self, you would save alot on installation costs,

Quite simple to fit, remove rh flexi cold inlet to your existing electric boiler, send the cold up to the swh copper coil heat exchanger, bring the hot return back to the cold inlet of the electrical cylinder .. JOB DONE

vacuum swh come in kit form so can easily be assembled at the point of use.

heres a picture of my solar setup on my house

bil

How much would the setup on your house be?

tony

HI bil

I only have 2 swh because one of them assists my under floor heating system
( solar day , wood bolier night)

1 X 160 LITRE 18 tube 58mm by 1,8m, stainless steel inner tank, 50mm insulation, galv painted outer shell, galv painted frame, top up tank

700€+iva

normaly diy fitting should take about 2 days, 1day assemble and mount swh, 1day plumbing

allow about 150 for fittings and pipe ( plastic is ok ) about 60 extra if you fit a thermostatic mixing valve

optional extras

imersion element 20€+iva

temp sensor and controller 60€+iva

Hey bil do you know anything about sterling engines ??

just wondered if the hot water from a swh could power one to generate electricity !!!