I would go with the same size as your header. The pipe will only cost a little more and will allow higher flow rates if needed in the future (expansion).
Solar Heating Results
- Thread starter bradatkins
- Start date
I too would pick 1.5 in a perfect world, just stated above that 3/4 would double the current flow, and 1 inch would double that again. However the reality is 1 inch would likely perform close to1.5 with your small bank of panels.