Pumping pressure related to heater.

[miatawnt2b]

So I completely re-plumbed my new pool to prep for solar install tomorrow. I put in a couple bypass valves, one between the solar in/out and the other between the heater in/out. So I was curious how much pressure the heater introduced to the system and I was actually shocked. My pool is roughly 21k gallons, with a pentair sand filter and an intelliflow VS. My pool high setting is set to 3000 RPM on the pump speed. With the heater inline my pressure on top of the sand filter is 22psi. If I open the heater bypass that I just installed, my pressure drops to 18.5psi. I was kinda taken back that the heater was that restrictive. I'm sure the solar will be quite restrictive as well, I'm anxious to see that number tomorrow (qty8 helicol 4x12 panels). All plumbing is 2"

So my question is will I gain efficiency of heating the water if I open the bypass valve on the heater a bit? If so, how much should I open it?

Thanks crew!

 

[kadavis]

The solar company should setup the proper flow rate for the solar. Usually Helicol recommends 5gpm per panel, so you really only want 40-45gpm going through solar panels. If your also using the gas heater you have to be sure you don't bypass to much flow away from heater. Having a bypass between in and out pipes is a good idea, also having a VS pump allows you to fine tune for your system

 

[JoelFitz]

No, you do not gain efficiency by bypassing flow to the heater.

I tested it out at a friends pool and when we timed it we actually lost efficiency when we ran his VS at low speed 1250. It took almost 1.5 times as long to reach max temp versus max rpm 3450