3HP VS speed pump or single speed for solar panel equipped pool?

[norcalpool1]

My pool needs remodeling and all of the pool equipment I have need upgrade. The pump is somewhat leaking and I would like to replace the DE filter with cartridge filter because I don't have a good way of disposing of the DE (I do not want to the ground as I live near a community park).

The pool is equipped with solar thermal heaters. In the SFO bay area, I expect to see 6-8 months of decent sunshine to help heat the pool water. Would I see benefit from using the variable speed pump during those months? Would I have to run it at high rpm anyway to push the water up to the thermal heaters and back? Would a 3HP VS speed pump be sufficient? The panels are about 30 feet high at the highest point, and the pool equipment is about 30 feet away from the main drain of the pool.

 

[cfherrman]

You can check the head chart at the lower speeds to see if it will pump 30' high, which I'm guessing it should be able to

 

[mas985]

You will have to run at a fairly high RPM to both prime and run the panels. If the VRV (vacuum release valve), is at the top of the panels, then the RPM would need to be maintained throughout the run time. With a lower RPM, after prime, it might be possible to lower the RPM but only if the controller supports an RPM step down. Worst case, the VS will probably save you 10-15% in energy costs.

 

[Yankeefan1011]

I think that you would save money by going with a VS over a single. If your panels are like mine then they will require heat from the sun in order to heat your water, not just sunlight, and so you aren’t going to get much heat from them for probably half of the year. This means that you can bypass the solar for half the year and operate and low speed. I have a similar setup in SoCal and my panels are useless from about November to May. You won’t realize as much savings during the warmer months since you will need to operate at a higher speed during the prime electric rate hours in order to capitalize on the suns heat.

 

[norcalpool1]

I ended up with a Pentair IntelliFlo VSF (part 011056) installed about 10 days ago. IntelliFlo VSF - Efficient Pool and Spa Pumps - Pentair Water is not directed to the panels these days. The vaccum release valve is way up at the top of the panels.

 

[Yankeefan1011]

I have the same pump...awesome thing is that you can set the gpm that you want and it will auto adjust the speed when the solar valve opens so that you are only using higher speed during those times. I have found that I don’t need a sun or SolarTouch.