Thank you for the million dollar question. I have a 16000 gallon pool and by you calculation I can run my pump at like approx. 2000 to 2200 gallons for an 8 hour period. I don't have a solar heater, so I'm good with the approx rpms. I have the same pump. It may suck a few more gallons at the 2200 rpm speed, but that's ok. I remember reading in a pool forum, where a guy ran his pump 24/7 at 2200 rpm. This vid just saved me a ton of money and electricity. Thanks for this vid
Unbelievable helpful without having to buy flowmeters. I followed Mr. Mello dual pressure method by tabulating the RPMs to GPM and Watts on my Pentair. Then I normalized the data using excel and obtaining a fitting curve and equation for the GPM and Watts. I then calculated that I needed to circulate at least 1.5 times the pool volume per day calculating the needed hours for each pump RPM. I was thrilled to find on the plotted curve an optimum sweet spot between 1600 and 2200 RPM coinciding with the lowest Kw-h consumption possible. So instead of using 2800 RPMs for 3.5 hours (which I have been using since 2018) I found out that I can set it to 1800 RPM for 7.45 hours costing me $2.83 /day opposite to what I've been foolishly doing for over 5 years at $4.35 /day. The $1.52 savings per day X 365 days more than paid for the Vacuum gage and 1/2" nipple I bought at the hardware store. Thank you for this excellent video.
Hi, similar sentiments here. My previous pool care company put me onto the variable speed pump but left it at 2,800rpm basically cleaning 2-3 times my pool volume each day and Mr. Mello helped me put an end to that nonsense. I have a few questions for you, @fferes2163, wouldn’t the lowest KWH consumption be at the lowest RPM available and just run it longer to get to your 1-1.5x volume? I.e. I run mine at 1,400rpm for 11 hours a day and it’s “only” pulling ~160watts. Also why 1.5x your pool volume instead of just 1x? Glad to hear there’s more aficionados out there doing the leg work of plotting the pressure/vacuum data on excel. Thanks
Dear @@rnolet2. Not really. I was focused on the lowest Kwh consumption per day to achieve 1.5 x the pool volume. My pool is a salt system and requires 1-1.5x to create and saturate hydrochlorous acid thru out besides filtering the entire pool. My pump reads 227 watts at 1400 RPMs, so your power consumption is much less, you are lucky. Since I did not have a flow meter, I found that David Mello's video was sent from heaven. The pressure and vacuum gave me the TDH and Watts per each RPM and from the chart I obtained the GPMs. plotting the 4 points on Excel applying my Engineering knowledge I found out that that for each RPM there is a high, a low and a high again in wattage usage. This optimum pump's lowest wattage range is between 1400 and 2200 RPMs. The good news is that my neighbor's VS pump results produced an identical RPM range but with different GPMs since his plumbing is different than mine. However, we both concluded that the flow must overcome things like a pool waterfall and a decent water flow into the skimmer, so I had to run mine higher at 1800 RPM for 6.45 hrs. If you can run yours a1400RPM my calculation is 10.18 hrs. so you are in the correct zone and identical to my neighbor's. It saves pumps life, and it is very quiet. Since I am in Florida, I program it to run the pump while the pool is exposed to the sun, a chlorine killer. My calculations for optimum (RPM/HRS) performance and 1.5x are: 1400/1.18,1500/8.9, 1600/7.9,1700/7.1, 1800/6.45,1900/5.91, 2000/5.46, 2100/5.06, and 2200RPM for 4.72HRS. Occasionally, I raise it to 2800RPM only to temporarily run my Zodiac vacuum crawler twice per year or so.
@@rnolet2 The lowest watts consumption point calculated for my pump was actually 1600 RPMs but I had to raise it to 1800 RPM for 7 hours because I have a water fall that need a little more flow. You can use 1x to be able to filter the entire pool. I need a little more because mine is a salt pool and some of the Chlorine is lost to the UV exposure here in Florida. 1400 RPM for my pump shows 2.41Kwhrs during 10.18 hours of run time (1.5x) with 237.1 watts constant. My neighbor uses your program, so it is not a bad choice. I'd wish I could share my spreadsheet with you, but I do not know yet how. Anything over 2000 RPM it begins to sharply use more watts of power.
This was a very informative video and a very good example of practical engineering at its finest! I really wish this video had more visibility than the one I just watched on how VS pumps are a hoax meant to steal our money...... ugh. keep up the good work!
Genius....Just ordered a vacuum meter to get my flow rates for my ststem. Thanks so much for the info. Have nearly the identical system you have with 1.5 pvc pipes and with using your math, I'll be able to tell whether my 30-year-old pool heater is worth replacing! Thanks so much!
Your gage reading was in inchs of mercury and psi , not bars, but it didnt affect your calculations since you made the same mistake on both readings, and ratio remained same. Pentair used to have a pump run time calculator that would tell you how many hrs for a complete turnover you needed at diff. speeds. They removed it and instead just show you how much energy savings you would have if you switched from single speed pool pumps to their variable speed pumps.
Great detailed info. However I've decided to install a flow meter on my return side to have continuous GPM readings without having to repeatedly refer to THD charts and then use that to adjust the schedulle for my VS pump.
Sounds good. Certainly the most convenient way if you have the space to add one, but I’ve found once you have things dialed in once you shouldn’t need to change it again unless maybe your filter is dirty in which case you should just wash it. If I had the space I might have done the same just because I’d nerd out about the exact gpm.
Thanks for the video, I'm using this to do my calculations on my pool. I do have one question though. While looking into the conversion factors I found the following cited everywhere I looked online: "CALCULATE TDH - Multiple the Vacuum gauge reading x 1.13." The factor seems to be 1.13, not 1.3 as stated. Just bringing this up in case anyone else is seeing this. Or perhaps you have a reason for using 1.3 instead.
Ya that was a mistake I caught a bit ago I had updated the spreadsheet and article on www.davidmello.com/calculate-gph-flow-rate-pool-pump-savings/ with the 1.13
I have the same pump and just bought a vacuum gauge to do these calculations. My vacuum readings are very low. At 3450 RPM it is 4 and below 2500 RPM it is close to zero. And when get down to 1400 RPM both my vacuum and pressure readings are 0. So that is not even on the pump curves. Yet I know that 1400 RPM is the cutoff for my heat pump to work which is at 20GPM. So using the Pentair performance curve, the TDH is about 12 @1400 and 20GPM. And I did test more than one vacuum gauge to make sure the readings are correct.
011075 (3HP) vs 011065 (1.5HP) Is it more efficient to run 3HP at 20gpm or the 1.5HP unit at 20gpm ? Will 1.5HP be more efficient across the board, but louder, and lower peak flow?
Here's some additional helpful info to mesh with your solar heating considerations ; The majority of grid-tied solar electricity (PV) systems are based around the concept of trickling electricity back into the grid during daylight hours (credits) and drawing from the utility at night. However, the utility will usually credit or purchase the electricity from you at significantly less than you do from them. Heating water directly is still FAR more efficient than converting sun energy to electricity and then to heat, but as far as electricity consumption for equipment goes, if you have PV, it is to your benefit to consume as much of your PV power onsite as it is generated before being "credited" (at a loss to you) back to the utility (at a profit to them). The trick. of course is to maximize this low-level consumption while attempting to avoid being a net consumer during peak hours. This is the premise for battery storage systems-store and consune your own generated electricity without selling it back to the utility at a loss. So long story short, if you have PV, you could see up to a double-digit percentage gain in electrical efficiency by running your pump at a low speed during all daylight (production) hours in-between high-flow times rather than waiting for cheaper night rates. Of course, the variables include pool/pump size, PV size, other household loads, geolocation, ant 1000 other things. Personally, my PV generated kW-hours are nearly double what my utility shows on my bill as credits, and that is because our air-conditioning is gobbling up the difference before it gets to the meter. In essence were denying the utility half of the convenience fee they would charge us fore time-shifting our consumption the way they encourage us to. This is exacerbated because our PV is oversized.
Great video, very succinct and good pace. I usually have to play videos like this at 1.5x speed because their pace is too slow. Your pace is perfect, nice job!
Great information, but IMHO you miss the final transition to put a $$ amount to the Energy efficiency = KWH. Maybe that's in some of your other videos/references. Anyway - at 7m10s into this video you introduce the wattage. Using your numbers, we can calculate the KWH needed for a full pool refresh. Essentially multiplying watts time runtime of course. Result: @2700=6.9, @2100=4.4, @1900=3.6. Now with my current rate of 30c/KWH that's daily $1.60/$1.31/$1.09 or monthly $48/$39/$33 - staying on one speed = sort of max saving. Adjust for your time/speed selections. Whether full pool turnover is critical, enough, or too much is an entirely other discussion.
First of all Very informative video and calculations. However, my readings when used with your formulae yield numbers that exceed the Total Dynamic Head curves and therefore I cannot extrapolate the GPM value on the x axis. Any idea? Could it be the two factors (2.31 and 1.3) are different for my system? Any suggestions would be appreciated. Thank you!
From what I understand from recent reading, for many pool systems the pressure reading would better be done using the 2nd port on the pump itself. (If I'm not understanding something please let me know.) In your setup it does not matter because you have no backwash valve in-between to add more resistance, but for those that have a backwash valve (or anything in-between that can add notable head), they might want to use a pressure gauge on the pump (in addition to the vacuum gauge on the pump). (It is important that the pressure gauge be located on the port that is farther back toward/under the impeller.). I took measurements today using the pressure gauge on top of my filter, but the resulting GPM from my pump's curves is much too high to be correct. I assume it is because my readings are not factoring in my multiport valve. I'm now waiting for another pressure gauge to arrive. (BTW, I don't know how much it matters, but Measureman claims the fluid filled gauges are important where there is a lot of vibration - which would be true on a pump. I asked 3 pool shops and they did not seem to know anything about fluid filled gauges.)
this is exactly my situation as well! I did the calc using the guage on the filter but got low readings and not sure i trust them w/o measuring pressure right at the pump , rather than the filter.
Great stuff. But how did you determine that 1400 rpm would be enough to pump water to the solar panels on the roof? I don't think I'd run the pump that slowly anyway, but....
Hello, thank you for your video! Can you dumb it down for me? Where did the factors 2.31 and 1.3 come from in regards to pressure and vacuum? Are they on the gauges?
having a new VS pump installed shortly - and after seeing this I feel like I have wandered into a minefield. I have no clue how to use gauges to calculate the regular pool run time rpm. I have a 25 to 30 k gallon pool. Had a challenger high flow pool pump mod 196251 - new mod is a 011028. i do have a spa - that I want the flow rate to be a higher - when I use it but beyond that I just want my pool pump to turn over my system at least the minimum of 1 time a day at a reduced rate from the old pump. Geesh... i need help.
This is if you really want to scientifically dial it in/optimize it. If it’s being installed ask if they can install a flow meter for you in line if you have space. Then you don’t have to do so much math since the flow is directly measured.
I wanted to filter the equivalent of the total gallons of water in the pool at least once per day so once I had my gallons per minute flow rate I was able to determine what my runtime would need to be at a given pump speed. I used 3 different speeds as shown to optimize for the solar heater in some parts of the day and also so my suction-side pool cleaner works correctly. After, I multiplied each of their runtimes by their GPMs at that speed and added them together to make sure I had a total gallons value roughly equivalent to the volume of water in the pool.
Great example, I plan to use it. BTW, I notice that the folks on Trouble Free Pool advocate that with their recommended pool chemistry (most notably FC at 7.5% of CYA) turns of water each day is not important. Filtration has its place, and water movement has its place, but they advocate that one should not expect your filtration to keep your water sanitary. If you are not already familiar with the TFP view on this, you might want to check it out, I'm curious your thoughts on this.
I wasn't trying to imply having the proper levels of sanitizing chemicals wasn't also needed, but that they will work more effectively when the pool is being filtered and the water is circulating. For sure there is a balance. Trouble free pool is a great website.
@@reallyMello I was not suggesting you were implying that. I was more curious your thoughts about the idea their turning over the water of a pool each day is not particularly important if one is following their chemistry guidelines.
I did a test last summer…. I ran my single speed pump only 3 hours a day to the horror of most common wisdom. I’ve never had a green pool and last summer was the same. Kept FC appropriate for my CyA level and pool was perfect. Moral is circulation is less important than proper FC level. Much less important.
Great video! It helps out a lot. On the last step you select speeds that don't have curves on the performance chart. How did you get their flow rates? Estimate based on the existing speed curves on the chart?
Great video Very helpful. How do I do this with my pumps that are not using a filter. I have a couple pumps that feed my water features and do not have a filter with a pressure gauge. How do I find to dynamic head for those? Thanks in advance for the help.
Same process essentially but you’d need to find a place to add a pressure gauge on the pressure side since you don’t have a filter that happens to have one already in that case. There are also flow meters you can plumb in instead if you have the room as another option.
My gpm fluctuates from 58 gpm to 48 gpm. 3000 RPMs is what it’s set at. Why do you think this happens all the time? I backwash and skimmers are always clean. This is a weekly occurrence for me. Equipment is brand new since December of last year. 🙏
@@reallyMello not moment to moment. I’d say it stays fluctuating from 52-58 most of the day and then in the evening, it’ll drop. 42-48. I never touch the RPMs.
@@reallyMello It's on anything you read. I don't even have my pool yet but everything I see and read says this for residential pools. They describe it as 1X getting about 66%, 2X about 90% and 3X about 95%. Definitely some diminishing returns and if your water is good, then you don't need to change.
It does vary depend on things like bather load and if you run a salt cell etc. trouble free pool has an article www.troublefreepool.com/wiki/index.php?title=Turnover_of_Pool_Water
Great video. I have supermax vs at 3000rpm vacuum=7 & filter=12 TDH=35.63 (35) the chart shows 80gpm. Confused as to how I have lower TDH than you but chart shows more GPM. The lower TDH= higher GPM. I used 1.13 for vacuum & 2.31 for filter. What am I missing. Thanks again for the video.
Aquired a house with a pool and pentair superflo vs variable speed pool pump. Original pool was installed in 1991. Same pentair vs pump. Where to find an instruction manual for it?
Thanks for asking Jeff because you made me realize I had a mistake on the vacuum when I rechecked the source material. Vacuum should be 1.13 not 1.3. www.hayward-pool.com/assets/documents/pools/pdf/manuals/HydraulicPumpSizingDiagnostics.pdf
Have you ever used pressure gauges with hoses that you would attach to the pump as an alternative to using the method here? Can you do a video using them? Thank you!
@@reallyMello Oh, I see, you lowered the cleaning RPM's and raised the Filtering RPM's to stay within what your solar system can work with, Nice job, thanks
@@jayortiz6893 my solar system has a diverter valve that will bypass the roof if the pool is hot enough or if the roof isn’t hot enough to heat. That typically means most days it starts heating around 8am or so. I need to make sure the RPMs are high enough during those times.
1:38 misread the pressure gauge... 12 bar you said, but that 12 comes from the red circle so those would be psi, or 0.8 bar... would you double-check that?
Thanks for catching that Emiliano. I meant to say PSI which is the red circle like you mentioned. So I took the correct number, but said the wrong term. You take the PSI and Hg numbers for the math on this one. Hope that clarifies things!
@@reallyMello Awesome! I knew it! Thanks! Great video... trying to make it work on my 23,000 gal pool with 2" PVC pipes (45 lf) 1 tee, 4 90s, 3 45s... a bit confusing but getting there!
You'd want to keep the flow rate under 80gpm max for 2" pipes. The process and calculations would be the same for 2" pipe, but be sure to stay under the 80gpm max vs a ~51gpm max on 1.5" lines. The numbers themselves will differ depending on how much pipe is in the system, diameter, the bends, height, etc so you'd need to check the gauges and find the numbers specific to your system.
I’m using the superflo vs so it is a different chart, but it does sound like you matched the performance curve chart to your model online…so it’s not that…
@@reallyMello Yeah i didnt know if my pressure readings were too high forcing it to be off the curve. Or if there is a different variable when using the multiplier depending on pump/filter
Multipliers would be the same but for vacuum it should be 1.13 I think I may have misspoke at one point in the video and said 1.3. I updated the spreadsheet to fix it.
Thank you thank you thank you for putting this up. Any chance you can share the spreadsheet you put together? Would love to use it as a reference for my own calcs.
Question: The chart you used, Is it for your specific pump? If so what was your horsepower? I have a 3hp Pintair VS and using your chart at 3450 with Filter at 30 and Vacuum at 9 I get DH at 81. From your chart that equates to only 40GPM. The 3hp says at 3450 it is around 90GPM.
Hi Billy, it is specific to the pump so mine wouldn't apply if you have a different model or HP. It will be in your manual if you still have it (or on the pentair website). If you have the 3 HP Intelliflo variable speed they have it online here www.pentair.com/content/dam/extranet/nam/pentair-pool/residential/manuals/pool-pumps/intelliflo-vs/intelliflo-vs-pump-manual-english.pdf starting on page 26.
Thanks Jay, you are right I misspoke. Another comment thread caught that previously and the spreadsheet I attached has the correct factor now. Thanks for bumping the correct info to the top.
BTW, you are off over 20 GPM from Swimming Pool Steve Your math is off Where in the world do you think we are getting the factor you used to multiply, see what I mean, you did not explain the tools you used. This video helped absolutely NO ONE!!!!!!!!
I misspoke at one point in the video on the factor but updated the article and spreadsheet on www.davidmello.com/calculate-gph-flow-rate-pool-pump-savings/ with the correct calculation
Using the pressure gauge on the filter is the wrong way to do this, you should be using the drain on the back of the pump. Also, you forgot to install your bond wire on the pump!
@@reallyMello it's wrong because the pressure at the filter is variable depending on what kind of debris you have in there. There's a reason they put the drain holes on both sides of the pump, it's for the gauges. Bonding lug looked empty to me, but after zooming in, I think I see a green sleeved conductor. What in the world is a green sleeved conductor doing there? It's always a bare wire bond from the pump to the pool shell.
Thank you for the million dollar question. I have a 16000 gallon pool and by you calculation I can run my pump at like approx. 2000 to 2200 gallons for an 8 hour period. I don't have a solar heater, so I'm good with the approx rpms. I have the same pump. It may suck a few more gallons at the 2200 rpm speed, but that's ok. I remember reading in a pool forum, where a guy ran his pump 24/7 at 2200 rpm. This vid just saved me a ton of money and electricity. Thanks for this vid
Unbelievable helpful without having to buy flowmeters. I followed Mr. Mello dual pressure method by tabulating the RPMs to GPM and Watts on my Pentair. Then I normalized the data using excel and obtaining a fitting curve and equation for the GPM and Watts. I then calculated that I needed to circulate at least 1.5 times the pool volume per day calculating the needed hours for each pump RPM. I was thrilled to find on the plotted curve an optimum sweet spot between 1600 and 2200 RPM coinciding with the lowest Kw-h consumption possible. So instead of using 2800 RPMs for 3.5 hours (which I have been using since 2018) I found out that I can set it to 1800 RPM for 7.45 hours costing me $2.83 /day opposite to what I've been foolishly doing for over 5 years at $4.35 /day. The $1.52 savings per day X 365 days more than paid for the Vacuum gage and 1/2" nipple I bought at the hardware store. Thank you for this excellent video.
I’m glad you were able to apply it and run more efficiently
Hi, similar sentiments here. My previous pool care company put me onto the variable speed pump but left it at 2,800rpm basically cleaning 2-3 times my pool volume each day and Mr. Mello helped me put an end to that nonsense. I have a few questions for you, @fferes2163, wouldn’t the lowest KWH consumption be at the lowest RPM available and just run it longer to get to your 1-1.5x volume? I.e. I run mine at 1,400rpm for 11 hours a day and it’s “only” pulling ~160watts. Also why 1.5x your pool volume instead of just 1x? Glad to hear there’s more aficionados out there doing the leg work of plotting the pressure/vacuum data on excel. Thanks
Dear @@rnolet2.
Not really. I was focused on the lowest Kwh consumption per day to achieve 1.5 x the pool volume. My pool is a salt system and requires 1-1.5x to create and saturate hydrochlorous acid thru out besides filtering the entire pool.
My pump reads 227 watts at 1400 RPMs, so your power consumption is much less, you are lucky.
Since I did not have a flow meter, I found that David Mello's video was sent from heaven. The pressure and vacuum gave me the TDH and Watts per each RPM and from the chart I obtained the GPMs. plotting the 4 points on Excel applying my Engineering knowledge I found out that that for each RPM there is a high, a low and a high again in wattage usage. This optimum pump's lowest wattage range is between 1400 and 2200 RPMs. The good news is that my neighbor's VS pump results produced an identical RPM range but with different GPMs since his plumbing is different than mine. However, we both concluded that the flow must overcome things like a pool waterfall and a decent water flow into the skimmer, so I had to run mine higher at 1800 RPM for 6.45 hrs.
If you can run yours a1400RPM my calculation is 10.18 hrs. so you are in the correct zone and identical to my neighbor's. It saves pumps life, and it is very quiet. Since I am in Florida, I program it to run the pump while the pool is exposed to the sun, a chlorine killer.
My calculations for optimum (RPM/HRS) performance and 1.5x are: 1400/1.18,1500/8.9, 1600/7.9,1700/7.1, 1800/6.45,1900/5.91, 2000/5.46, 2100/5.06, and 2200RPM for 4.72HRS. Occasionally, I raise it to 2800RPM only to temporarily run my Zodiac vacuum crawler twice per year or so.
@@rnolet2 The lowest watts consumption point calculated for my pump was actually 1600 RPMs but I had to raise it to 1800 RPM for 7 hours because I have a water fall that need a little more flow. You can use 1x to be able to filter the entire pool. I need a little more because mine is a salt pool and some of the Chlorine is lost to the UV exposure here in Florida. 1400 RPM for my pump shows 2.41Kwhrs during 10.18 hours of run time (1.5x) with 237.1 watts constant. My neighbor uses your program, so it is not a bad choice. I'd wish I could share my spreadsheet with you, but I do not know yet how. Anything over 2000 RPM it begins to sharply use more watts of power.
This was a very informative video and a very good example of practical engineering at its finest! I really wish this video had more visibility than the one I just watched on how VS pumps are a hoax meant to steal our money...... ugh. keep up the good work!
Thank you!
Im taking a CST pool course and your video taught me more than the class did. Well done on the video!!
Thanks!
Genius....Just ordered a vacuum meter to get my flow rates for my ststem. Thanks so much for the info. Have nearly the identical system you have with 1.5 pvc pipes and with using your math, I'll be able to tell whether my 30-year-old pool heater is worth replacing! Thanks so much!
Awesome to hear!
Excellent, simple, and clear! I like your mellow voice too.
By far the best explanation of very complicated information. Thanks so much for this breakdown.
Thanks Kathy!
Your gage reading was in inchs of mercury and psi , not bars, but it didnt affect your calculations since you made the same mistake on both readings, and ratio remained same.
Pentair used to have a pump run time calculator that would tell you how many hrs for a complete turnover you needed at diff. speeds. They removed it and instead just show you how much energy savings you would have if you switched from single speed pool pumps to their variable speed pumps.
Aha! Cool, thanks for letting me know.
This is super helpful and easy to understand. Thank you!
You're very welcome!
Great detailed info. However I've decided to install a flow meter on my return side to have continuous GPM readings without having to repeatedly refer to THD charts and then use that to adjust the schedulle for my VS pump.
Sounds good. Certainly the most convenient way if you have the space to add one, but I’ve found once you have things dialed in once you shouldn’t need to change it again unless maybe your filter is dirty in which case you should just wash it. If I had the space I might have done the same just because I’d nerd out about the exact gpm.
Thanks for the video, I'm using this to do my calculations on my pool. I do have one question though. While looking into the conversion factors I found the following cited everywhere I looked online: "CALCULATE TDH - Multiple the Vacuum gauge reading x 1.13." The factor seems to be 1.13, not 1.3 as stated. Just bringing this up in case anyone else is seeing this. Or perhaps you have a reason for using 1.3 instead.
Ya that was a mistake I caught a bit ago I had updated the spreadsheet and article on www.davidmello.com/calculate-gph-flow-rate-pool-pump-savings/ with the 1.13
@@reallyMello Thank you, I didn't realize you had published the spreadsheet so I was recreating it when I found that issue.
I have the same pump and just bought a vacuum gauge to do these calculations. My vacuum readings are very low. At 3450 RPM it is 4 and below 2500 RPM it is close to zero. And when get down to 1400 RPM both my vacuum and pressure readings are 0. So that is not even on the pump curves. Yet I know that 1400 RPM is the cutoff for my heat pump to work which is at 20GPM. So using the Pentair performance curve, the TDH is about 12 @1400 and 20GPM. And I did test more than one vacuum gauge to make sure the readings are correct.
011075 (3HP) vs 011065 (1.5HP) Is it more efficient to run 3HP at 20gpm or the 1.5HP unit at 20gpm ?
Will 1.5HP be more efficient across the board, but louder, and lower peak flow?
Here's some additional helpful info to mesh with your solar heating considerations ; The majority of grid-tied solar electricity (PV) systems are based around the concept of trickling electricity back into the grid during daylight hours (credits) and drawing from the utility at night. However, the utility will usually credit or purchase the electricity from you at significantly less than you do from them.
Heating water directly is still FAR more efficient than converting sun energy to electricity and then to heat, but as far as electricity consumption for equipment goes, if you have PV, it is to your benefit to consume as much of your PV power onsite as it is generated before being "credited" (at a loss to you) back to the utility (at a profit to them). The trick. of course is to maximize this low-level consumption while attempting to avoid being a net consumer during peak hours. This is the premise for battery storage systems-store and consune your own generated electricity without selling it back to the utility at a loss.
So long story short, if you have PV, you could see up to a double-digit percentage gain in electrical efficiency by running your pump at a low speed during all daylight (production) hours in-between high-flow times rather than waiting for cheaper night rates.
Of course, the variables include pool/pump size, PV size, other household loads, geolocation, ant 1000 other things. Personally, my PV generated kW-hours are nearly double what my utility shows on my bill as credits, and that is because our air-conditioning is gobbling up the difference before it gets to the meter. In essence were denying the utility half of the convenience fee they would charge us fore time-shifting our consumption the way they encourage us to. This is exacerbated because our PV is oversized.
Great video, very succinct and good pace. I usually have to play videos like this at 1.5x speed because their pace is too slow. Your pace is perfect, nice job!
Thanks Ed!
Great information, but IMHO you miss the final transition to put a $$ amount to the Energy efficiency = KWH. Maybe that's in some of your other videos/references. Anyway - at 7m10s into this video you introduce the wattage. Using your numbers, we can calculate the KWH needed for a full pool refresh. Essentially multiplying watts time runtime of course. Result: @2700=6.9, @2100=4.4, @1900=3.6. Now with my current rate of 30c/KWH that's daily $1.60/$1.31/$1.09 or monthly $48/$39/$33 - staying on one speed = sort of max saving. Adjust for your time/speed selections. Whether full pool turnover is critical, enough, or too much is an entirely other discussion.
First of all Very informative video and calculations. However, my readings when used with your formulae yield numbers that exceed the Total Dynamic Head curves and therefore I cannot extrapolate the GPM value on the x axis. Any idea? Could it be the two factors (2.31 and 1.3) are different for my system? Any suggestions would be appreciated. Thank you!
From what I understand from recent reading, for many pool systems the pressure reading would better be done using the 2nd port on the pump itself. (If I'm not understanding something please let me know.) In your setup it does not matter because you have no backwash valve in-between to add more resistance, but for those that have a backwash valve (or anything in-between that can add notable head), they might want to use a pressure gauge on the pump (in addition to the vacuum gauge on the pump). (It is important that the pressure gauge be located on the port that is farther back toward/under the impeller.). I took measurements today using the pressure gauge on top of my filter, but the resulting GPM from my pump's curves is much too high to be correct. I assume it is because my readings are not factoring in my multiport valve. I'm now waiting for another pressure gauge to arrive. (BTW, I don't know how much it matters, but Measureman claims the fluid filled gauges are important where there is a lot of vibration - which would be true on a pump. I asked 3 pool shops and they did not seem to know anything about fluid filled gauges.)
this is exactly my situation as well! I did the calc using the guage on the filter but got low readings and not sure i trust them w/o measuring pressure right at the pump , rather than the filter.
Same here. It says I’m pushing less gpm at higher rpm. Can’t be correct. Wonder if the pressure gauge on second port on pump would work.
Wow excellent video…
Thanks
My guy so helpful . Thankyou
Great stuff. But how did you determine that 1400 rpm would be enough to pump water to the solar panels on the roof? I don't think I'd run the pump that slowly anyway, but....
@@timgedney8613 because when I went too low water wasn’t coming out of the pool jets
@@reallyMello Makes sense, thanks.
Thanks for the help.
Where do the 1.3 and 2.31 factors come from? Are those based on anything variable like pipe sizing or something or are those universal?
I misspoke in the video the first number is 1.13, see www.davidmello.com/calculate-gph-flow-rate-pool-pump-savings/ for full article
Hello, thank you for your video! Can you dumb it down for me? Where did the factors 2.31 and 1.3 come from in regards to pressure and vacuum? Are they on the gauges?
It's a fixed multiplier for the TDH formula. I explain it a little more long form here www.davidmello.com/calculate-gph-flow-rate-pool-pump-savings/
Thank you, I see more clearly.
having a new VS pump installed shortly - and after seeing this I feel like I have wandered into a minefield. I have no clue how to use gauges to calculate the regular pool run time rpm. I have a 25 to 30 k gallon pool. Had a challenger high flow pool pump mod 196251 - new mod is a 011028. i do have a spa - that I want the flow rate to be a higher - when I use it but beyond that I just want my pool pump to turn over my system at least the minimum of 1 time a day at a reduced rate from the old pump. Geesh... i need help.
This is if you really want to scientifically dial it in/optimize it. If it’s being installed ask if they can install a flow meter for you in line if you have space. Then you don’t have to do so much math since the flow is directly measured.
Excellent video--but we all more explanation on how to arrived at the optimum rate --- I think it was ratios and proportions right?
I wanted to filter the equivalent of the total gallons of water in the pool at least once per day so once I had my gallons per minute flow rate I was able to determine what my runtime would need to be at a given pump speed. I used 3 different speeds as shown to optimize for the solar heater in some parts of the day and also so my suction-side pool cleaner works correctly. After, I multiplied each of their runtimes by their GPMs at that speed and added them together to make sure I had a total gallons value roughly equivalent to the volume of water in the pool.
Great example, I plan to use it. BTW, I notice that the folks on Trouble Free Pool advocate that with their recommended pool chemistry (most notably FC at 7.5% of CYA) turns of water each day is not important. Filtration has its place, and water movement has its place, but they advocate that one should not expect your filtration to keep your water sanitary. If you are not already familiar with the TFP view on this, you might want to check it out, I'm curious your thoughts on this.
I wasn't trying to imply having the proper levels of sanitizing chemicals wasn't also needed, but that they will work more effectively when the pool is being filtered and the water is circulating. For sure there is a balance. Trouble free pool is a great website.
@@reallyMello I was not suggesting you were implying that. I was more curious your thoughts about the idea their turning over the water of a pool each day is not particularly important if one is following their chemistry guidelines.
I did a test last summer…. I ran my single speed pump only 3 hours a day to the horror of most common wisdom. I’ve never had a green pool and last summer was the same. Kept FC appropriate for my CyA level and pool was perfect.
Moral is circulation is less important than proper FC level. Much less important.
@ericrandall3539 nice, thanks for sharing your results!
Great video! It helps out a lot. On the last step you select speeds that don't have curves on the performance chart. How did you get their flow rates? Estimate based on the existing speed curves on the chart?
Thanks. Yes, I made some estimations based on those curves.
The power of interpolation!
Help me ---The vacuum gauge that I bought is leaking glycerin..
Is it vented or?
Great video Very helpful. How do I do this with my pumps that are not using a filter. I have a couple pumps that feed my water features and do not have a filter with a pressure gauge. How do I find to dynamic head for those? Thanks in advance for the help.
Same process essentially but you’d need to find a place to add a pressure gauge on the pressure side since you don’t have a filter that happens to have one already in that case. There are also flow meters you can plumb in instead if you have the room as another option.
Did you by chance publish your excel/sheets template?
Yes there is a link to it in the video description
My gpm fluctuates from 58 gpm to 48 gpm. 3000 RPMs is what it’s set at. Why do you think this happens all the time? I backwash and skimmers are always clean. This is a weekly occurrence for me. Equipment is brand new since December of last year. 🙏
From moment to moment it increases and decreases or gradually decreases? How are you measuring it?
@@reallyMello not moment to moment. I’d say it stays fluctuating from 52-58 most of the day and then in the evening, it’ll drop. 42-48. I never touch the RPMs.
@@reallyMello I’m measuring it based off the Pentair app on my phone.
Do you have any automated things in line like heaters or water features?
@@reallyMello we have the hot tub and water fall and yes a pool heater. Only thing running is the pump/ water flow over the hot tub.
But I thought we needed to turn over the water at a rate of 3X the total gallons, so shouldn't you be pumping 57k gal/day?
I’ve not heard of that for residential
@@reallyMello It's on anything you read. I don't even have my pool yet but everything I see and read says this for residential pools. They describe it as 1X getting about 66%, 2X about 90% and 3X about 95%. Definitely some diminishing returns and if your water is good, then you don't need to change.
It does vary depend on things like bather load and if you run a salt cell etc. trouble free pool has an article www.troublefreepool.com/wiki/index.php?title=Turnover_of_Pool_Water
excellent presentation, but you most likely misspoke 12 bar = nice explosion on that dial,,,,
i get it, you meant 12 psi,,,,,still great video
Thanks David, yep I misspoke in the moment :)
install a flowmeter Its far better and you can see it live at any time......this is the way to go ...Right?
More of a direct measurement for sure if you have the space to put it in
How did you get to your GPMs for 2600, and 1900?
Slightly inferred from the curves
Excellent video, thank you. However, how did you come up with 32gpm with the solar panel and the 51gpm for 1.5" pipes? How many gpm for 2" pipes?
The link you provided below answered my question. hayward-pool-assets.com/assets/documents/pools/pdf/manuals/HydraulicPumpSizingDiagnostics.pdf
Roughly 63gpm for 2" according to www.swimmingpoolsteve.com/pages/pipe-size.html
Great video. I have supermax vs at 3000rpm vacuum=7 & filter=12 TDH=35.63 (35) the chart shows 80gpm. Confused as to how I have lower TDH than you but chart shows more GPM. The lower TDH= higher GPM. I used 1.13 for vacuum & 2.31 for filter. What am I missing. Thanks again for the video.
Hi John there will be a chart specific to your super max pump with different curves
vacuum number & Pressure number where do i find these numbers
I have a link in the video description
Are you making these calculations while the filter is being bypassed? Or just after a backwash?
With a clean filter in 👍
Aquired a house with a pool and pentair superflo vs variable speed pool pump. Original pool was installed in 1991. Same pentair vs pump.
Where to find an instruction manual for it?
www.pentair.com/content/dam/extranet/aquatics/pool-pad-pro-assets/pumps/inground-pumps/superflo-vs-variable-speed-pump/356292-superflovs-superflovst-supermaxvs-owners-manual.pdf
I 2nd that would love to have that spreadsheet
Thanks for reminding me. I added a link to it at the bottom of www.davidmello.com/calculate-gph-flow-rate-pool-pump-savings/
Where did you find the factor number from?
Thanks for asking Jeff because you made me realize I had a mistake on the vacuum when I rechecked the source material. Vacuum should be 1.13 not 1.3. www.hayward-pool.com/assets/documents/pools/pdf/manuals/HydraulicPumpSizingDiagnostics.pdf
Have you ever used pressure gauges with hoses that you would attach to the pump as an alternative to using the method here? Can you do a video using them? Thank you!
Hi Jay, I haven’t but if they provide the same vacuum and pressure readings the calculation would be the same
@@reallyMello Oh, I see, you lowered the cleaning RPM's and raised the Filtering RPM's to stay within what your solar system can work with, Nice job, thanks
@@jayortiz6893 my solar system has a diverter valve that will bypass the roof if the pool is hot enough or if the roof isn’t hot enough to heat. That typically means most days it starts heating around 8am or so. I need to make sure the RPMs are high enough during those times.
1:38 misread the pressure gauge... 12 bar you said, but that 12 comes from the red circle so those would be psi, or 0.8 bar... would you double-check that?
Thanks for catching that Emiliano. I meant to say PSI which is the red circle like you mentioned. So I took the correct number, but said the wrong term. You take the PSI and Hg numbers for the math on this one. Hope that clarifies things!
@@reallyMello Awesome! I knew it! Thanks! Great video... trying to make it work on my 23,000 gal pool with 2" PVC pipes (45 lf) 1 tee, 4 90s, 3 45s... a bit confusing but getting there!
That's great you have 2" pipes. It should have less resistance. I have an older house and pool where 1.5" was what they used at the time.
Was going to say but beat me to it by about 6 months
Hi, thanks for providing the info for 1.5 inch pipe what if you have 2" pipe? Thanks
You'd want to keep the flow rate under 80gpm max for 2" pipes. The process and calculations would be the same for 2" pipe, but be sure to stay under the 80gpm max vs a ~51gpm max on 1.5" lines. The numbers themselves will differ depending on how much pipe is in the system, diameter, the bends, height, etc so you'd need to check the gauges and find the numbers specific to your system.
@@reallyMello Great video, thank you so much. Where did you get the max flow for pipe size specs from? (51gpm for 1.5", 80gpm for 2").. Thank you!
I think I lost the site I bookmarked for that sorry. I’ll keep looking.
How did you come up with the 2600 rpm for first 2 hours of optimal run time?
That rpm was not used in the two charts.
Hi Patti, I inferred it off the other curves
Did u use ratios/proportions to figure optimum rate?
I replied in your other comment, but I also have an article here www.davidmello.com/calculate-gph-flow-rate-pool-pump-savings/
Hey any ideas if my reading are coming out above the curve?? For example at 3k my P was 26 and Vacuum was 9.5(this was after I cleaned the filters)
I just wanted to confirm first that you are using are the chart provided for your same make and model pump?
@@reallyMello Yeah I have the pentair Sta-rite supermax VS. Just in case i looked at the chart in the manual online.
I’m using the superflo vs so it is a different chart, but it does sound like you matched the performance curve chart to your model online…so it’s not that…
@@reallyMello Yeah i didnt know if my pressure readings were too high forcing it to be off the curve. Or if there is a different variable when using the multiplier depending on pump/filter
Multipliers would be the same but for vacuum it should be 1.13 I think I may have misspoke at one point in the video and said 1.3. I updated the spreadsheet to fix it.
Are you 1.5" lines just the return side? Great vid btw.
On both sides unfortunately. 2" would have been great to have.
Thank you thank you thank you for putting this up. Any chance you can share the spreadsheet you put together? Would love to use it as a reference for my own calcs.
Thanks Mike, I'll try and get that posted on my site soon.
Posted it on my site here www.davidmello.com/calculate-gph-flow-rate-pool-pump-savings/
where do you factor 2.3 and 1.3 ? is that a given number?
I misspoke on the video it’s actually 2.31 and 1.13 and they are givens
@@reallyMello thank you for the upload and reply
My pleasure I hope it helps you get your pool settings dialed in
You appear to have read PSI as BAR.
Yep I misspoke, a past commenter caught it too 😀
Question: The chart you used, Is it for your specific pump? If so what was your horsepower? I have a 3hp Pintair VS and using your chart at 3450 with Filter at 30 and Vacuum at 9 I get DH at 81. From your chart that equates to only 40GPM. The 3hp says at 3450 it is around 90GPM.
Hi Billy, it is specific to the pump so mine wouldn't apply if you have a different model or HP. It will be in your manual if you still have it (or on the pentair website). If you have the 3 HP Intelliflo variable speed they have it online here www.pentair.com/content/dam/extranet/nam/pentair-pool/residential/manuals/pool-pumps/intelliflo-vs/intelliflo-vs-pump-manual-english.pdf starting on page 26.
Hey! Can you explain how to calculate the factors to apply on pressure? Thanks !
Hi there I’m not following your question if you could clarify
@@reallyMello for calculating total dynamic head once you have the two pressures.
@@CyrilBoudot-hc4wk see if the accompanying article helps www.davidmello.com/calculate-gph-flow-rate-pool-pump-savings/
vacuum factor is 1.13 not 1.3, thanks
Thanks Jay, you are right I misspoke. Another comment thread caught that previously and the spreadsheet I attached has the correct factor now. Thanks for bumping the correct info to the top.
@@reallyMello Hi ReallyMello. I would like to request a copy of the spreadsheet. How can I download it?
I have it linked on www.davidmello.com/calculate-gph-flow-rate-pool-pump-savings/
youtalk wayyyyyyy too fast; but great explanations; well thought out
Thank you
BTW, you are off over 20 GPM from Swimming Pool Steve
Your math is off
Where in the world do you think we are getting the factor you used to multiply, see what I mean, you did not explain the tools you used.
This video helped absolutely
NO ONE!!!!!!!!
I misspoke at one point in the video on the factor but updated the article and spreadsheet on www.davidmello.com/calculate-gph-flow-rate-pool-pump-savings/ with the correct calculation
Using the pressure gauge on the filter is the wrong way to do this, you should be using the drain on the back of the pump. Also, you forgot to install your bond wire on the pump!
Where are you seeing that it is wrong to use the gauge on the filter? Also, the bonding wire is definitely connected to the lug on the pump.
@@reallyMello it's wrong because the pressure at the filter is variable depending on what kind of debris you have in there. There's a reason they put the drain holes on both sides of the pump, it's for the gauges. Bonding lug looked empty to me, but after zooming in, I think I see a green sleeved conductor. What in the world is a green sleeved conductor doing there? It's always a bare wire bond from the pump to the pool shell.