how many tubes in series

[2807]

Hello list

I currently have 2 banks of 3X20 47mm tubes on my pool shed roof & am intending to put another 4 lots of 20 tubes on the pool shed wall in 2 banks of 40 tubes.

Do you think that it will it be OK to plumb each bank in series with the existing 3X20 tubes for the winter (giving 2 lots of 100 tubes)?  I seem to recall that no more than 80 tubes in series was reccommended on the Navitron course I went on, but these are only going to be in place from September until April.

2807

[rt29781]

We have 150 tubes in two banks, one 90 and one 60 and we live in sunny SW France so I guess you will be ok at 100 tubes in the UK.  In summer the pump is on maximum though and temperatures at collector gets to 80C.  Stagnation happens fast....

[2807]

Hello rt29781

We have 150 tubes in two banks, one 90 and one 60 and we live in sunny SW France so I guess you will be ok at 100 tubes in the UK.  In summer the pump is on maximum though and temperatures at collector gets to 80C.  Stagnation happens fast....

Are your tubes 47mm or 58mm? ISTR they are 58mm - so if you have 90 of them in series 100 47mm tubes are not going to be a problem.

I am in between La Rochelle & Bordeaux, so can appreciate the comments re stagnation - after a 10 minute power cut in the middle of a June afternoon, I soon fitted a UPS so the controller & recirculation pump carry on regardless of the whims of EDF.

2807

[rt29781]

We have 58mm tubes.  We live in Aude between Carcassonne and Narbonne.