Reverse Return

Brad White_194

For reverse-return to work correctly, each terminal served (collectors in this case but radiation, coils, unit heaters for that matter), need to have identical pressure drops, within reason.

For the most part, reverse-return grants the same "potential" across any terminal, but under flow conditions, this will vary if the pressure drops differ much.

Chances are your collectors are identical, so please disregard this message :)

Bill B

Reverse Return

I have 6 banks of 30 tube solar collectors and was wondering what the "best" way to pipe them together would be. I was thinking about piping them in reverse return. Reverse return will take a little more piping but will allow the lower return water from my solar tank(s) to be introduced into all 6 panels instead of having one panel receiving the supply from the one next to it needing to heat "hot water hotter". I feel that I would get more energy out of the panels if I was not heating "hot water hotter" having say three panals in series times two. If the panels were in reverse return, the panel would have more of a delta across it. (What are your thoughts, hope I am right because I already have them piped that way. I guess we call that "reverse engineering").
Thanks
BillC

[Deleted User]

AGree....

Reverse return is the ONLY correct way to pipe more than one anythings (tanks, collectors, conditioners etc).

Can it be piped direct return? Absolutely, but figure in a bunch of circuit setters and a lot of uncessary time in testing and balancing, and then cross your fingers that some first year service technician does not come in and scramble your settings.

About the only exception to this rule is boilers. If you don't want flow going through the heat source ALL The time, then pipe them P/S with individual pumps with internal check valves.

ME

Bill B

Thank you for the insight. I thought I was doing the right thing. Had someone who I "thought" I should listen to but I am finding out that I did the right thing by piping every panel reverse return to maximize the performance out of every solar panel. The only reason I would not do it is to try and cut expence and since this is my house my labor is somewhat cheep.
Thanks!
Bill

[Deleted User]

Too true...

and I ASSumed that was the case, so for anyone reading this AFTER the fact, make sure the pressure drops are fairly equal or all is for naught.

Thanks for the back up professor Brad.

ME