Equipment question

[ajonesny]

Hello, this is my first post, though I have been reading it for a few weeks. I recently purchased a new property with a pool. This is the first pool I've had so this forum has been a tremendous help but I still have some questions.

The pool is about 35,000 gallons, 10' deep and narrow on one end and 3.5, deep and wide on the other end. I currently have a 1.5HP filter pump and a 3/4 hp booster pump for the solar. I also have a booster pump to power my Polaris 280. The solar runs along the edge of my property then to my single story roof which is a distance of about 150-170' before it goes up to the roof. I have also been given a 6 month old Raypak 406 that I would like to incorporate since I can't get my solar to heat my pool above 76 degrees.

Because I will need to modify the plumbing I have been thinking of upgrading to a variable speed pump. My pool guy says not upgrade to a VS because it won't circulate the water enough with my big pool. I called a pool builder who came out and told me I should upgrade to a single 3 HP VS to replace both the filter and solar booster pump. Sun touch controller

What I'm trying to determine is:

Will a VS really be of benefit?
If I run VS at a higher rpm during the day for the solar will there be much energy savings?
Because I have a booster pump for the solar is it still cheaper to operate than a pool heater?
How can I get my solar to be more efficient?

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[JasonLion]

Welcome to TFP!

If you are paying the typical California electric rates, then yes a VS pump is well worth getting. It will save at least 10% at the absolute minimum all the time, and much more than that any time you can slow the flow rate down at all from what you have now (which is almost certain).

The cost comparison between solar and gas heat depends on your electric and gas rates, but for most people most of the time solar is still going to come out less expensive, even with that booster pump.

The simplest way to improve the solar efficiency would be to use larger pipes for that long run from the pad to the panels. Also, a solar cover makes a huge difference, if you aren't using one already. It is also worth double checking that you are getting a high enough flow rate through the panels to get into their peak efficiency range. You have a large solar array, I would expect you to get a lot of heat out of it.

 

[pooldv]

It seems possible that your pumps aren't pumping enough flow for the distance, height and number of panels. I have noticed that my solar heat gain drops when it is time to clean my filter and the flow drops.

Are those panels facing south?
Do you have a solar controller?

We had solar panels for a year and had questionable results because I would turn them on before work if I thought it was going to be sunny enough and I thought I would gain heat. But shade and rain can reverse heat gains quickly. I installed the Solartouch solar controller last spring and it helped a lot more last summer than the summer before. It has a sensor on the roof that only turns on solar when there is heat available. So far this spring I have been able to maintain temps at or above the daily high temps. No cover.

I have never had a single speed pump, but I am extremely happy with the efficiency of my VS pump.

 

[ajonesny]

Pooldv the panels are facing south south east. I do have some trees that block the panels until 10:30. After that I have good exposure throughout the day. I am using a sun touch controller. We moved into the house in September. Here in Northern California we had some really hot days/weeks going into October. The controller was on auto mode and seemed to be performing properly but the pool never exceeded 76 degrees. When the booster pumped fired up for the first time of the day the water would be scolding hot then drop down to a luke warm feel.

The PB that came by recommended adding to flowmeter to dial in VS pump if I went that way.

 

[ajonesny]

Welcome to TFP!

If you are paying the typical California electric rates, then yes a VS pump is well worth getting. It will save at least 10% at the absolute minimum all the time, and much more than that any time you can slow the flow rate down at all from what you have now (which is almost certain).

The cost comparison between solar and gas heat depends on your electric and gas rates, but for most people most of the time solar is still going to come out less expensive, even with that booster pump.

The simplest way to improve the solar efficiency would be to use larger pipes for that long run from the pad to the panels. Also, a solar cover makes a huge difference, if you aren't using one already. It is also worth double checking that you are getting a high enough flow rate through the panels to get into their peak efficiency range. You have a large solar array, I would expect you to get a lot of heat out of it.

Yes, I'm in Northern California using PG&E. I'm always jumping into the tier 4 plan where electricity gets pricey.

I've thought about getting a solar cover to help with the heat and for evaporation with ongoing drought.


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[Divin Dave]

You mentioned also your PB recommended the VS to replace the booster for your Polaris 280. That wont work.
teh booster and filter pumps even though both are pumps, are entirely differnt designs.
Booster pumps are low flow high pressure pumps
Filter pumps are high flow low pressure pumps

You are still gonna need the booster pump for the 280 to work like its supposed to.

Also as a FYI, Pentair makes a variable flow "VF" pump, which is a variable speed pump with a display that tells you what the flow rate is.
Its a couple hundred dollars more than the regular VS pump is though. Maybe some other pump manufacturers make VF, but Im not for sure.

 

[pooldv]

Pooldv the panels are facing south south east. I do have some trees that block the panels until 10:30. After that I have good exposure throughout the day. I am using a sun touch controller. We moved into the house in September. Here in Northern California we had some really hot days/weeks going into October. The controller was on auto mode and seemed to be performing properly but the pool never exceeded 76 degrees. When the booster pumped fired up for the first time of the day the water would be scolding hot then drop down to a luke warm feel.

The PB that came by recommended adding to flowmeter to dial in VS pump if I went that way.

All of that sounds good. Bummer that all those panels can't heat your pool! Seems like increasing the water flow through the panels is th next option and a heat pump after that.

 

[ajonesny]

You mentioned also your PB recommended the VS to replace the booster for your Polaris 280. That wont work.
teh booster and filter pumps even though both are pumps, are entirely differnt designs.
Booster pumps are low flow high pressure pumps
Filter pumps are high flow low pressure pumps

You are still gonna need the booster pump for the 280 to work like its supposed to.

Also as a FYI, Pentair makes a variable flow "VF" pump, which is a variable speed pump with a display that tells you what the flow rate is.
Its a couple hundred dollars more than the regular VS pump is though. Maybe some other pump manufacturers make VF, but Im not for sure.

Correct. My PB did say we must keep the 280's booster pump. Maybe a VF is a better option for me.