Concrete Solar Thermal

[Onoff]

Interesting article (I thought so anyway) using good old concrete as the collector:

 

https://www.google.co.uk/url?sa=t&source=web&rct=j&url=http://web.cut.ac.cy/cost1/wp-content/uploads/sites/13/2017/03/55..pdf&ved=0ahUKEwiY29j5sq3TAhUHhywKHV5EDtgQFggwMAQ&usg=AFQjCNGjOdbJ75Sj2YtokyhBI8iYTT9W-A

[Barney12]

I'm scared to open the link in case it refers to 'thermal mass' 

[SteamyTea]

2 minutes ago, Barney12 said:

I'm scared to open the link in case it refers to 'thermal mass'

You're alright, they call it thermal storage.

 

I made a similar system for a swimming pool back in 1984.

[Onoff]

Seems an ideal project for leftovers; Pex-Al-Pex and PIR / Icynene offcuts. Just bond all the bits together with gun foam in a sacrificial timber frame! No glass to clean and the "blacker" it gets the better. You could even build the frame and add the concrete over time with those odd bits left in the mixer.

[Onoff]

1 hour ago, SteamyTea said:

You're alright, they call it thermal storage.

 

I made a similar system for a swimming pool back in 1984.

 

And it worked OK?

[PeterW]

I've got 40m or so of Pert-Al-Pert if anyone wants to try ... 

[SteamyTea]

4 hours ago, Onoff said:

And it worked OK?

Yes, if anything it could run the pool too hot.  I only had a manual OnOff switch on the pump.

There is a big difference in running up to 28-30°C for a swimming pool and getting up over 50°C if you want to rely on it for DHW.

Easy method for cheap pre-heating when the conditions are right.

I used some cheap agricultural semi-rigid black water pipe laid on a gravel bed, then poured dyed concrete on top.

If I was doing it again I would put some insulation down instead of gravel.

And make a control system.

[Onoff]

Black patio anyone?