Setting up the system

[mick]

Ivan,

We have just about installed my system - 20 tubes, 172 lt vented 3 coil cylinder, pressurised solar loop - and are now setting it up.

But, although we attended your excellent course I can't seem to find answers to the following questions. (Rather than phone yet again I am following instructions and posting here.) ......

1) We have pressurised the system (and found and rectified some small leaks!!) but the Reliance 3 bar pressure release valve vents off at 2.4 bar reading on the pressure gauge supplied - is that of any consequence?  (As a matter of interest my mains pressure manages a measly 2 bar so we had to pump our garden spray bottle like mad!)

2) What cold pressure should we start up with? What pressure should the system normally run at?

3) Is my memory correct that the anti-freeze you supplied should be diluted to 40% mix - the pump states that 30% is the maximum?

4) The Taconova flow meter supplied - is it already calibrated for a particular anti-freeze mixture? Or is that taken care of by the BS4 controller?

5) When I bought the flowmeter it came with a fourth temperature sensor (T4/TRF) with a black lead. Is it interchangeable with the others (it has a 1.5 metre lead which would be fine for T1!)? Can I simply tape/wire it to the exit pipe from the solar loop, under the insulation, of course?

6) What should the flow rate be?

I am sure there will be further questions but that's it for now - can't wait to slot the tubes in.

Mick.

[Ivan]

Hi Mick,

1. The PRV should operate at around 3bar. It could be the gauge is not particularly accurate, or if you look at the guage at an angle, it may appear to read incorrectly. In any case it should not affect the system unduly, as it should be operated at 1bar pressure, and no higher.


2. The cold pressure should be 1bar. The expansion vessel will absorb the extra volume so there should be negligible change in pressure when hot.

3. There is no set concentration for the antifreeze, but we recommend 40% which will protect down to about -25C.  The pump manufacturer does not recommend over 30%, but they seem to work perfectly well at 40%. In fact, some installers run 100% antifreeze, and this seems to work ok too! We do not recommend 100% antifreeze, as it is quite viscous and the pump has to work hard to circulate 100% glycol.

4. The flowmeter does not need to be calibrated for different working fluids, as it is simply measuring flow. If the fluid is more viscous, the flow rate will be lower. You can input the flowrate and circulation medium into the controller for it to calculate the kWh readings.

5. The black sensor is the high temperature lead for the solar panel. It is interchangeable with the other leads, but obviously you need to use the high temperature probe for the panel to avoid meltdown in hot conditions.

6. You wil need to experiment by trial and error to find the most suitable flow rate. I asked Resol for guidance, but they cannot offer any help.


Ivan

4.

[mick]

Many thanks Ivan for your instantaneous reply - another night owl!

Mick.