I am planning on installing 450 ft2 of solar heating panels (9 panels of Heliocol HC-50, 4 x 12.5 ft. each) using 2" pipes. I currently have a Jandy Zodiac FloPro FHPM 2.0 2-speed pump. I will need to run the pump in high-speed mode when solar is on, and low-speed mode otherwise.
After installation, I might try to change (likely downgrade) the impeller to target the ideal flow rate to the solar panels in high-speed. Some people here have suggested adding a flow meter like FloVis:
on the feed side going to the solar panels. Since this is something that I will only have to do once and the flow meter will forever forward generate some back pressure and increase the work of the pump, does this make sense to do this? I was looking at some of the approximate flow calculation spreadsheets some people here have created, and none I found mentions my pump. Any input would be much appreciated!