8 hrs at 60 gpm vs 24 hrs at 20 gpm

15 years ago

I will soon be helping someone install an Intelliflo VS pump in a 17k gallon pool. The hope is to run it at 20 gpm for most or all of a 24 hour period instead of, say, 60 gpm for 8 hours. Obviously the two scenarios result in the same daily filtration.

Most on this forum agree that this is far more energy efficient, especially if plumbing friction losses can be reduced. I'm curious, however, if this forum thinks that that this will result in an overall cleaner pool. In my observation, debris seems to float on the surface of the pool and then eventually sink to the bottom if it doesn't make it to the skimmer. If you are only running the pool for 1/3 of the time, even if at a higher flow rate, that leaves 2/3 of the time that the debris will probably drop to the bottom. It seems that if 20 gpm will move the water to the skimmer, even if it is slow, that it would be better to have that happening 24 hours a day than a higher flow rate for 1/3 the time.

What do you think?

Sort by:Oldest

Comments (6)

mikethepoolguy
15 years ago
You may need to runthe pump once or twice a day at a higher speed. Some things may/will not work at 20 gpm. Take advantage of the multiple speeds and runtimes. If you dont you might just want to save some money and get a 2- speed pump. Setting up a vsp for perfection may take weeks of tweeking.
repair_guy
15 years ago
Huh???

You may want to revisit your calculator...

60gpm at 8 hours is almost 29000 gallons. If you desire to turn your 17k pool over once a day and that's pretty much all you need, you only need 14 hours. Debris typically hit the pool at the time when the wind is greatest. Run your pool cleaner mode at that time and you'll accomplish good skimming and cleaning. Drop to the lower rates for the rest of the single turnover period. You have to figure the increased spped for the cleaner mode and you can adjust to less than 14 hours for additional savings.
Related Discussions
Pellet Stoves - Harmon Accentra, Advance vs Quadra-Fire
Q
Comments (34)
We are on our third heating season with a quadrafire insert. We heat the main part of our house--an area of approximately 1300 square feet. Noise was a consideration in our puchase (it is in our TV room) as was quality and looks. We have been extremely happy with our stove. We program the thermostat just like we would for our oil boiler. The hopper holds one 40lb bag of pellets. The burn pot is self cleaning. Once per week we thoroughly vacuum the burn chamber, clean the glass, and empty the ashes from the lower tray. We have it serviced annually. The amount of ash in the tray and dust in the pellets varies with the brand of pellets you burn. This year we found a dealer (in CT) that offered several different brands of pellets and detailed the wood and size of pellets. Our price for pellets was about $2.25 per bag--purchased by the ton. We will burn just over 2 tons. Quadrafire Mount Vernon insert. (60,000 btu)
...See More
AC vs. Advanced Evaporative Cooler
Q
Comments (3)
Thanks V, Today Im having another vendor that is actually doing a heat-calc. Finally. My model number is 58MXA10011116, and I digged some specs: IP(MBH), OP(MBH),AFUE(%) 100.0, 93.0, 92.0, It is supposed to deliver a max CFM of 1315. I suppose there are some losses in the duct system -- which has two sizes, corresponding to two different vent outlets. Without actually measuring those metal (alloy, like alum) ducts (I'll get there!)I'd say ducts seem to be have an OD 6" and perhaps 10", I may be off, they have quite a bit of insulation. I got many quotes, right now I can write here numbers of those who send emails. What is disturbing is that many of the vendors said right of the bat that the furnace was too small, and we would need to replace it with a bigger 80% AFUE. Well, Im glad we did not heed those matter-of-fact recommendations.. I wonder how many people fall for those? One guy offered (among other less top-of-the line items) Trane XC95: TUH3C100ACV4VA XL20i A/C : 4TTZ0048A1000A XL20i Heat Pump : 4TWZ0048A1000A. Other did offer to install this: Carrier 80% A.F.U.E Infinity Series Variable speed furnace with 110,000 B.T.U.H Heating Input. Model # 58 CVA110-1--20, Connected to (1) Carrier Puron cased performance series "N" Coil with 4 Tons of Cooling model number CNPVP4821ATA. From The Evaporator Coil an Insulated line set will be connected to (1) One Carrier Infinity Series up to 17 S.E.E.R (4) four tons of cooling condenser with (2) Two stages of cooling. model number 24ANA748A003. Other people just offered to couple our existing furnace with some Carrier condensers that were 4tons, per the model number. Nobody seemed keen on following up on the advanced evaporative coolers, which are very appropriate for this dry climate. Some of this swamp coolers demand a fraction of the electricity, and do not consume the level of water that traditional swamp coolers do - yet, the vendors are pushing the A/Cs in this area hard - i wonder. Thanks for your thoughts, I think this is reassuring. Will post more numbers, etc. mia
...See More
Water Softener Sizing - SFR vs capacity
Q
Comments (10)
The maximum flow rate through a 3/4" line is 15gpm. The pressure it is delivered at needs to be considered also. There will be about a 10-15 psi pressure drop through the softener. A Fleck 7000 or Clack WS1 (1.5cuft) 45k system would provide about 16gpm with this pressure drop. The 25gpm you stated is the max flow rate with all fixtures running. A general rule is 1/2 that flow rate is required for typical usage. Either of these systems at your present water usage would regenerate about 30 days. The system should not sit that long in between regens for fear of hardness bleed through at low flows. Both of these system have a 14 day override to regenerate. As your families water use increases this can be reset to normal operation. At a 6# salt dose you would use about 13# per month and have a salt efficiency of 3000 grains per pound. At $8 for a 50# bag (Dura Cube or Hardi Cube, I strongly recommend to use high grade salt) this would equate to $25 yearly salt usage. There would not be any advantage to a twin tank system in this application because of the water usage and water chemistry. Low hardness can greatly effect the efficiency of tankless water heaters. Most manufacturers recommend treatment of water supplies with high mineral content. 1300 grains of daily hard water x 365 = 474,500. 7000 grains = 1# of dissolved mineral. In 1 yrs time your home currently has 67#'s of dissolved mineral build up. This is why even low hardness can cause problems in a home. I hope this helps, RJ
...See More
Intelliflo VF vs. VS Question
Q
Comments (82)
Thank you, that will save me some time if I switch over. Since everything is glued together including the threaded fittings into the pot I would have to replace two 3-way valves. Not a huge deal just more time and money. I just installed a 2-speed motor and it seems to be adequate at low speed. However, as the filter pressure increases the flow dramatically decreases. I was thinking a little more RPMs would be nice maybe around 2,000 or so. I have been using PhosFree to remove the Phosphates, which are now low so the flow problem may go away and the 2-speed motor may be fine. I can buy a lot of DE for the price of a VF and Intellicom. I am a little hesitant to install a variable speed pump. I had my variable blower motor fail on my house heater. Fortunately it was just inside the 5 year warranty but it still cost $280 in service calls. Could have been $280 plus over $750 for the motor.
...See More
djensen
Original Author
15 years ago
Repair guy,

I realize that 29,000 gallons is more than necessary. I used the numbers I did because I was trying to compare equal gallons circulated in both scenarios. I'm assuming that, given good plumbing, it is probably not practical to slow down the intelliflo below 20 gpm. Since the power consumption is supposed to be so low at these low volume rates, I had read that you could make a good argument for leaving it run 24/7. But, yes, you could certainly reduce the run time substantially. Because it is not possible to know when it is going to be windy and because power consumption is so low, I thought that this would be a very economical way to keep the pool very free of debris that would otherwise settle to the bottom.

I take it from your answer that, in windy conditions, 20 gpm is probably not adequate skimmer flow. The pool has a screened cage over it so it is only debris that can get through the screen that can get into the pool.

Thanks for your time.
poolguynj
15 years ago
Heaters and salt cells also have flow needs that normally exceed 20 gpm too.

Scott
clearwaterguy
15 years ago
Is this a true Intelliflo VS or the 4X160 (4X100)? I have set up many of these pumps. With the VS, I usually program in the minimum flow needed to make sure an SWG will work or a heater will fire (some people do heat their pool). I then add about 5% to account for filter wear (filter cycles will shorten over time) and have had very good success. This seems to be the best balance, for me, between energy savings and maintenance. Sooner or later you will have to do maintenance, but I have yet to go back on any of these systems to have to "tweak" them. Call backs cost me money, so I do my best to avoid them. No one has been unhappy with a VS.
djensen
Original Author
15 years ago
"Is this a true Intelliflo VS or the 4X160 (4X100)? I have set up many of these pumps. With the VS, I usually program in the minimum flow needed to make sure an SWG will work or a heater will fire (some people do heat their pool)."

clearwaterguy, I just now saw your question from a month ago. Sorry. Yes, it is the VS or 4X160 (not the VF). We don't have plans to install a heater or SWG so I don't think there will be a lower limit in that respect. We should be finally getting this installed this week and I am very anxious to check out the performance (reduced current draw) on the low end!

8 hrs at 60 gpm vs 24 hrs at 20 gpm

Comments (6)

mikethepoolguy

repair_guy

Related Discussions

djensen
Original Author

poolguynj

clearwaterguy

djensen
Original Author

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

8 hrs at 60 gpm vs 24 hrs at 20 gpm

Comments (6)

mikethepoolguy

repair_guy

Related Discussions

djensenOriginal Author

poolguynj

clearwaterguy

djensenOriginal Author

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

djensen
Original Author

djensen
Original Author