Solar thermal collector autoconstruit: what solution?

[cortejuan]

Hi,

in fact I have four new glazings from a large brand of windows: they made a mistake in the installation of small woods between the 2 panes when replacing my windows so I got them for free.

So I have 4 of 1,75m high and 42 cm wide which makes a total area of ​​3m2, if I combine the 4.

But hey if it is not the right solution, I can turn to something else.

The sensor will have to be effective in autumn and spring to increase the difference between the temperature of my water supply and the temperature of the greenhouse in order to have enough energy during very cold weather.

I remind you that I inject the heat of the greenhouse into a reserve of water during sunny periods and then I use this heat to heat the greenhouse at night via car radiators. All this works very well except when it freezes hard where I have to have a gas top-up.

Of course, to increase the efficiency of my system, I could increase the flow rate of my pumps and the speed of the fans but it is not good for pumps, for plants and for power consumption and anyway when i 'reach 10 degrees (my set temperature) I don't gain anything anymore.

Hence the idea of ​​a more optimized sensor input than a greenhouse ...

cordially

[chatelot16]

that makes a rather small surface compared to the greenhouse

the window double glazing is not tempered: mounted horizontally it will be broken at the first hail

it is better to sell your double glazing to make windows, and make a lot more than 3 m2 of solar collector with plastic film

the insulation of the solar collector is less important than the insulation of the greenhouse: the pump must circulate the water only when it heats ... when there is not enough sun we let everything cool

I will even contradict my previous message: a plastic sensor with a large volume of water is not bad, if when we stop the pump all the heated water returns to the tank ... when the sun comes back, as soon as 'a well placed thermostat detects that it can heat it turns on the pump and circulates water already at the right temperature: you don't have to wait for it to heat up: the water volume of the sensor is no longer a disadvantage

[cortejuan]

Hi,

thanks for the advice, i will think about all this.

What you are proposing is actually simpler to realize than from my hyper-heavy glazing ... My greenhouse is leaned against a hangar whose roof is oriented due south so by installing the sensor on the roof it should play.


cordially

[Other]

Hello

http://aulapinblanc.blogspot.ca/2011/03 ... laire.html


Son has made a similar assembly remains to know the performance this winter.

Andre

[BobFuck]

> mounted horizontally it will be broken at the first blow of hail

Yes

> it is better to sell your double glazing to make windows,
> and make much more than 3 m2 of solar collector with plastic film

Yes

> the pump should only circulate the water when it is heating up ...

You also need an anti thermosiphon to prevent the sensor from turning into garden heating at night ...

I was asking you how many m² of sensors you can put, and where, because the installation and fixing method is important to find the cheapest solution. For example, if you have a garden shed with a south-facing sheet metal roof, that's perfect. You can also take the opportunity to build yourself a garden shed ...

As "gypsy" sensors, I propose:

- rear structure: sheet metal or OSB tank
- insulation: PIR slab 3cm
- sensor: flat pool heater, or house sensor (PVC membrane, wet acrylic felt, mylar)
- air blade
- plastic film for the greenhouse effect

You come out at 20 € / m², add poles and you have a garden shed as a bonus.

[chatelot16]

You also need an anti thermosiphon to prevent the sensor from turning into garden heating at night ...

in winter when the effective heating period is short, it is especially necessary to empty the sensor every time it no longer heats, to recover all the water already hot ... if we just stop the circulation this hot water will cool ... and the beginning of the next period of sun will be lost to warm it up

[dedeleco]

Totally agree with Chatelot16.

This subject was already realized on Apper in a simple and effective way and reproduced on econology with also the yield of the evaluable sensors, changing little, whatever the complexity, of the realization, with free or very expensive recovered material, and even under vacuum, much less strongly than the price !!! .

It is more important to respect the laws of elementary physics, with almost free recovery.

The good quality film for greenhouse on this cheap 16mm drip tube sensor (30 € per 100m) isolated from below (a few cm) is the best solution.

http://www.apper-solaire.org/Pages/Expe ... index.html

http://www.apper-solaire.org/Pages/Fich ... /index.pdf
http://www.apper-solaire.org/?Faqhttp:/ ... tml#206800

https://www.econologie.com/forums/post206800.html#206800

https://www.econologie.com/forums/post210733.html#210733


http://www.apper-solaire.org/?Theorie
http://www.apper-solaire.org/?Pratique

and what is remarkable:

http://www.apper-solaire.org/Pages/Expe ... 20toiture/

[cortejuan]

Hi,

thank you all for your advice, I will let the thing mature further, but it is slowly taking shape in my head ...

cordially

[chatelot16]

I've been looking for solar collectors for a long time with the lowest possible price per m2: can replace all ordinary roofs

there is this kind of sheet metal which gives me some idea
http://www.agraco.fr/spip.php?article57
http://www.castorama.fr/store/Plancher- ... 80001.html

but it is not the right size, it should be done with the right size to wedge 16mm tubes

it's not the right price either: it should be little more than normal corrugated iron

the tube would receive the heat directly from above ... and from the sides the heat collected by the sheet

the sheet is a good seal so that this system can serve as the main roof, even if the plastic film above is demolished by the weather the roof remains waterproof


while waiting to make the right profiled sheet, we can do tests with normal corrugated sheet, a pipe in each wave, welded mesh mesh unwound over to keep the pipes in place ... polyethylene film for greenhouse, then a new layer of mesh to hold the film ... and screws with large washers to prevent all of it from flying away

[cortejuan]

Hi,

I also had this idea of ​​using corrugated iron, a very available and inexpensive material, but the result must remain pleasant to the eye, especially as with me the roof that will carry the thing is in small old tiles.


cordially