Solar Owners Whats Pump Speed and Run Time

#1
Hey all,

I just had solar installed for my new IG pool and looking for others that have solar to chime on the pump speed and how long they leave their pumps running when on.

I'll go first: Pump Speed 2850 RPM, Running 10:00 - 6:00 pm everyday.

My solar guy set this up initially and after hooking up the screen logic automation I may have accidentally changed the Pump speed to 2850.

Thanks.
 

pooldv

Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
Aug 10, 2012
24,993
DFW, TX
#2
I set the pump to run daytime hours only so it isnt running water through colder plumbing/filter at night and cooling the pool. It runs at 1200 rpm standby speed and 1950 rpm solar on speed. I arrived at 1950 rpm by a combo of feeling the solar panels and feeling the water from the returns. I increased the speed until the panels felt relatively cool and the water from the returns didn't feel overly warm. Also, there isn't much vertical lift for our panels so that contributes to the relatively low speed. Height of top header row is only about 10' above the pump.

Conversely, when using the panels to cool in july/august I run the pump during night time only.
 

BasicTek

Bronze Supporter
Oct 9, 2016
802
Lake Mary, FL
#3
My solar guys installed mine and set the pump for 2300 for 8 hour runtime, on my 2nd season I've modified things.
In the winter if I don't expect to be swimming (the cold weeks we had in january) then I run the pump about 5 hours during peak daylight at 1800 (my pool is covered and I try to keep it at least in the 70's in case a warm spell comes)

in the borderline months nov, dec, feb, march I run the pump at 1800 for about 7 hours of peak sunlight
my solar controller needs the temp in the panels to be at least 5 degrees warmer than the pool water to turn on so I set the pump run time based on that.

In my 1st season I used to run the pump up to 3000 thinking that the more water I ran through the solar the faster it would heat my pool, this is only true if the sun is exceptionally hot (and on those days I probably don't need the solar), in the fall, winter, spring when I need the solar the most I find that running anything over 2350 doesn't really make a difference or not enough of a difference to justify the electric bill for using that much power. My solar is up 1 story and 1800 is about the minimum I can run my pump when the panels are engaged.

So based on when the solar engages on average I set the run time (currently 9AM to 6PM) @ 2000, if it's really sunny and I want more heat I'll temporarily up the pump to 2200 - 2350.

After a cold start to the week, and my solar cover is off for the season because it's going in the trash I was still able to enjoy 88, 89, 88 over the last 3 days with only medium warm temps, if I still had my cover I'd be in the lower 90's which I like this time of year.

Finally in peak summer, since I have a screen I still run the solar, but only in the AM and have it cut off when the pool hits 89 - 90 the pool never gets hotter than 92 apparently due to the screen so I never have to use my solar to cool the pool.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
4,377
Central California
#4
I figured out even before I installed that there would be no way to optimize the heat exchange between panels and the water by guessing RPMs, or even by trial and error. The manufacturer of my panels clearly states how to optimize them, and they would know, and they spec that in flow, GPM (gallons per minute), not RPM. The RPMs are not really something to use for this, because of the many variables. Type of filter, height to roof, length and size of pipes, size and type of pump, etc. Every pool would be different. It's possible to guestimate flow by doing a lot of measuring of your plumbing and equipment, and then applying some math, but you only end up with an estimate. That wasn't for me, so I installed a flow meter that actually tells me what my flow rate is! EZPZ. No guessing, no measuring, no math. I just look at the flow meter and adjust the RPMs for the perfect amount of flow through my panels (which is 40 GPM).

The FlowVis I bought for this purpose was about $150. I figured that would be a one time expense, for a one time use, to dial in my panels, and just considered it part of the installation cost. But it turns out I use the flow meter for all kinds of other things, in addition to keeping an eye on the flow though my panels, which does change over time. So if I had to do it again, I'd want a flow meter even if I didn't have a solar system, it's that handy.

If you have a Jandy check valve in your system, you can buy just the guts of a FlowVis for about $100, and it'll retrofit right into your Jandy (you won't have to cut PVC or re-plumb anything.

So you can try the math. Or hold your hand in front of the return. Or do some trial an error. All perfectly fine ways of getting close. But if you want it perfect, and want to know that it's perfect, I recommend forgetting about RPM and get the right tool to determine GPM...

Amount of solar time? However long I need to run solar to get the pool to the temperature I want. No hard and fast rules, just whatever works for that particular time of year. Also quite easy to figure out: if it's warm enough, then turn off the solar. Repeat tomorrow.

Oh, if you still want to know, I run my solar at 2200 RPM.