Unconnected Solar Panels

ShortPockets

Just got solar panels installed on roof of a new build. They are not filled or connected to the cylinder and wont be for a few weeks. A relation who built his own house says that they will get damaged by the sun if not connected to the cylinder? I rang the supplier and was told they are fine as they are. Any views?

homer911

Vacuum collector tubes should not be exposed to the Sun for extended periods without connection to a manifold with coolant.

If this is a flat panel system, I dont think it'll be a problem

- Not an expert though!

CJhaughey

Panels can get pretty hot without fluid running though them, can you pull a tarp over them while you are waiting?

AckwelFoley

Take my advice and cover them.

ShortPockets

Done. Thanks everyone.

AckwelFoley

No problem.
Another satisfied patron.

NEXT!

'tis such a pity they arn't connected now, t'would have filled a couple of cylinders ó hot b' now.

Still trying to get mine up & running :mad:

CJhaughey

Thats for sure! I had 72c in the top of the tank, and 65 on the bottom, panel temps were around 75 all afternoon.

cunnings

CJhaughey wrote: »

Thats for sure! I had 72c in the top of the tank, and 65 on the bottom, panel temps were around 75 all afternoon.

Im only getting c. 45 degrees at the cylinder.... What type of panels did u put up. I have 3 m2 veissmann evacuated tubes on my garage with 300 L triple coil stainless steel cylinder (large surface area solar coil) in the house. The garage is south facing and 5 metres from the house (total distance from panel to cylinder = c12 metres). I have the correct High temp insulation on pipework all the way to the hotpress. The outside temp is 22 degrees with no clouds...any ideas what could be wrong??

bertie1

Sounds like you havn't enough panels. 12 meters out & 12 meters back is a lot of pipework to heat up (& liquid inside in it ) before the temperature in the tank starts to rise


Our tank got to 60 C today ( 450 liter tank) We have tubes

CJhaughey

I have 6m2 of flat panels and a 400l tank.
Pipework runs about 4-5m and the roof is SW facing.

MickLimk

bertie1 wrote: »

Sounds like you havn't enough panels.

+1 on that.

The cylinder sizes recommended are normally 50litres/m2 of panel. It is possible to go smaller or larger than that but it has effects:
Smaller (35l/m2) can cause the system to go into stagnation on a good solar day and possibly blow off through the pressure relief valve if the expansion vessel is undersized.
Larger (75l/m2) will cause the issue you're facing - water not getting as hot as expected. Makes sense when you think about the energy transferred to the cylinder. You've got a larger quantity of cooler water where if you had a smaller cylinder, you'd have a smaller quantity of hotter water.

Sounds to me like the install wasn't sized right & allowance should have been made for length of runs.

homer911

...makes me think I should have gone for a bigger tank: 4m2 of tubes with 300l produced 76C yesterday in the middle of the tank. On a good day the temp differential between middle and bottom of the tank is only a couple of degrees