Aloha & help! We are off municipal water, and I want to use the garage as a rainwater catchment system to feed the house water supply. Thats very typical here in Hawaii, except that the garage water tank & pump is 200 feet from and 6' below the house entrance, where the 85 gal pressure tank is located. The 10-12 GPM pump is appropriately sized (200+ Hft) for PSI and line/fitting losses. My question is: Where do I install the (40/60) pump pressure switch - at the pump, the pressure tank, the farthest/highest fixture, or does it make any difference? I understand the static (no-load) pressure is the same no matter what the pipe diameter or where horizontally in the system it is located. I am less clear on the effects of the appox 9 psi loss (1-1/4" PEX 200' pipe friction & 6' rise) from the pump to the pressure tank, the appox 24 psi loss (3/4" PEX 60' pipe friction, connecting to 1/2" fixtures w/nominal run, & 15' total rise) from the pressure tank to the last fixture, and the flow rate and pressure changes as the pressure tank cycles. Said differently, I want to be sure I have a minimum of appox 40 psi for up to 10 GPM use anywhere in the line, at any time.
Thanks so much for your thoughts. [I can attach a diagram & pump performance curve chart if thats helpful]
Thanks so much for your thoughts. [I can attach a diagram & pump performance curve chart if thats helpful]