New Solar Thermal Install

[kalas666]

Good morning all.  Having been a reader of these pages for quite a while I finally got my logon sorted.

The Lads at Navitron managed to squeeze me in before the deadline for PV Fit cuts, for which I am very greatfull.

Now my attention has moved to my Solar thermal install.  I already have a 475 ltr TS with a solar coil fitted.  I have space left on my roof (just) for a 30 *57 ET.
I am happy that a TDC3 will do what I need, but I need some help in specifying the rest of the system.

The ET's will be 7 meters above the TS, with the pipework taking a fairly direct route through the loft space then a cupboard to reach the ground floor.
I need some help determining the diameter of pipe to use and where in the chain to site the expansion vessel and bleed vents.

Any input greatfully received.

Chris

[micko]

The bleed vent needs to go on one of the top elbows of the ET tube manifold, there is a way of bringing this into the loft space with a bit of fancy pipe work, I have seen a diagram on this forum somewhere. I would go for 10mm copper, a for the expansion vessel I am not sure, I don’t think it really mattes, you will fill the system at this point so somewhere where you can get easy access to mains water.


Here we go, link to air vent.

http://www.navitron.org.uk/forum/index.php/topic,5911.msg60160.html#msg60160

[kalas666]

Thanks for that, interesting read.  I think I'll just go for risers off the pipework in the loft, although as the panel is going to be sited quite high on the roof, it may be a bit awkward...

Do you have any guidance on the size of the expansion vessel?

[micko]

Hi,

I have much the same pipe run as you, I am using a 12 L expansion vessel with a system pressure of 2 bar. I am also using an eco pump, this is not compatible with a TDC3 so I’m using a TDC2.

[kalas666]

What is so special about the 'eco pump' your using? and why won't the TDC3 run it?

Chris

[micko]

The Ecocirce pump will run as low as 9W compared  to a standard pump that starts at around 40W.

With a TDC 3 the pump relay is  electronic, after playing with one I found even when the relay is in the off position it leaks current, enough to start the pump running. With the TDC2 it just has standard relays. The pump is sited in my loft and I was concerned with pump noise, the Ecocirce is silent.