Re: pooldv pool thread
I decided to post a discussion about pump speeds, skimming, heating and cooling in this thread for future reference.
My speeds for the 011018, Intelliflo, 3hp variable speed pump are as follows.
I started at 900 rpm and got flow errors on my SWG. I tried 1000 rpm and got an occasional flow error if the filter was dirty. So, I ended up at 1100 rpm, no flow errors in 5ish years. Then I worked on the eyeballs to get good skimming. I ended up reversing the flow to counterclockwise with the eyeballs pointing pretty much parallel to the water surface. So, at 1100 rpm I get good skimming, can make chlorine and be on standby for solar heat. The pump uses 150 watts at 1100 rpm. At 10.25c/kWh I can run 24x7 for less than 12 bucks per month.
For solar I started at 1800 rpm on a hot day. First is to make sure the flow can close the VRV, vacuum release valve, which it did. Then feel the solar panels to see if they are hot. And feel the water from the returns to see if it is hot. I went up 50 rpm until the panels felt fairly cool to the touch and the water in the returns didn't feel too hot. I ended up at 1950 rpm and it uses 550 watts.
For the waterfall we usually put it on the 1950 rpm speed, if it isn't already because solar is on and then adjust the water flow with the 3way valve that splits water flow between waterfall and returns.
Since we added the heat pump last fall I wanted a little more flow than the 1100 rpm to make sure I get as much heat from it as possible. So, I run the pump at 1500 rpm when running the heat pump is on. I do this manually by setting the pump timer to turn on at 1500 rpm at 8a and off at 10p. Not running the pump at night cuts down a little on overnight heat loss. Then the heat pump timer is set to run from 10a to 8p or to 85 degrees. I chose 1500 rpm for no particular reason. I need to check the inlet and outlet temps, Hayward recommends adjusting flow so you see a 2°c temp rise.
Then the 4th speed we use is 2500 rpm which is used for extra skimming and/or bottom drain suction when cleaning up a messy pool after a storm or something.
Max speed and priming speed is set to 3000 rpm, although I'm thinking about lowering that to 2500 also.
This set up has worked great since the summer of 2012, except for the heat pump which I installed in September, 2016.
A few more notes on solar.
Since I started running the pump at 1500 rpm when the heat pump is on then when solar turns on the Solartouch ramps the pump to 1950 rpm and when it turns off it reverts back to whatever speed it was on, either 1100 rpm or 1500 rpm. I noticed that when solar shuts off and reverts to 1500 rpm the pinhole in the solar valve cannot open to drain the panels, they do drain at 1100 rpm. Leaving the water in the panels to get HOT. My heat pump is plumbed after the solar panels so now I can see the temp of the water exiting the solar panels. Typically, when solar is on the exiting water temp is 1 to 2 degrees warmer. But, there are a few times when spots of shade from the tree hit the solar temp sensor and shut off solar throughout the day and if the pump is on 1500 rpm then the panels don't drain. I was observing this recently when solar turned back on and the exiting water temp was 102 for a few minutes. This was after solar was off for less than 30 minutes so it could get a lot worse if it was off for longer. I need to check my heat pump entering and leaving water temps to see if it can run at a lower rpm that will allow the solar panels to drain when solar shuts off.
A few notes on the SWG
My SWG is wired to its own timer, Intermatic time clock. I run the SWG well inside the run window for my pump. If my pump is set to run 8a to 10p then I'll set the SWG to run from something like 10a to 8p and adjust the percentage and/or the SWG run time to dial in the correct FC level. It is important to sync up the times regularly because the Intermatic timer will lose the time that it is off from a power outage and the pump will retain the time during a power outage. So, if the power is off for 15 minutes the times will have a 15 minute time difference when the power is restored. We don't have many power outages that last a long so my timers don't get very far off normally.
Heat conservation
I run my pump 24x7 in spring and fall when the trees are busy. But to conserve heat I run the pump 8a to 10p when I'm trying to heat the pool because I lose more heat overnight if the pump is running water through cold plumbing and filter. Solar cover is mostly on 24x7 when we are heating the pool. Conversely, I run the pump at night from 10p to 10a during summer to shed heat. I also enable pool cooling on the Solartouch so it will turn on solar at night to cool the pool if needed. The heat pump also has a cooling option but the solar panels have always been able to cool the pool enough in the past.
I put the cover on and turned solar on in late February to start the long, slow process of heating up the gunite, ground and water. Once that is all heated up maintaining water temp is much easier.
Our preferred swim temps are 88 to 92 degrees, 86 is our lowest comfortable swim temp. Solar is set to heat to 93 and cool to 91. This is the first spring using the heat pump so I'm still experimenting. Mostly, I set it to heat to 85 if we won't be swimming in the next few days and I move the start time back to noon to 8p to give solar more time to heat. If we will be swimming then I'll move the time to 10a to 8p and the temp to 86 or 87. Then a couple of days before, like Wednesday or Thursday, I'll look at the weather and the current pool temp and run the heat pump more if it will be cloudy or rainy or the water temp is lower, like 80ish. The heat pump can raise the water temp 1 degree in a little over 3 hours and solar can raise water temp by 2 degrees per hour on very sunny days and 1 degree every couple of hours on cloudier days or none ever if it is raining, windy or cold.
As the sun is getting hotter I'm struggling a little to let the solar panels do more heating for free without risking colder water when it is time to swim. I know, poor me.
