Replacing pool pump - any recommendations?

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You want the check valve after the filter so debris doesn't get stuck in it. Both locations will stop flow but a check valve between the pump and filter can get debris stuck in it and keep it open.
 
Sounds like I should keep shopping for another pool company to do this job, if they keep pushing for this check valve b/w the pump & filter and won't do as I desire. So, the 2 check valve locations that would be needed on my system would still be the one after coming from the solar and the one after the filter. No more, no less, right?
 
Yes that is correct. Pool companies have certain ways they do things and are often resistant to change. Plus really do not understand hydraulics very well.
 
If you have 2" plumbing, either will work but the larger check valves have less head loss but not by much. They should be close to the same price though.
 
Found another pool tech I have been speaking with. I shared my intentions about the MaxFlo, GFI breaker, and Jandy check valves. Initial talks are going okay, but I am trying to get him out here to visualize what my setup so he can give me a quote. In a recent call though, one thing came up that I figured I would have to bring up here.

He told me that he s/w his Hayward rep. and explained to him my setup. The pool tech told me (what I anticipated) that the Ecostar would be better suited for my needs, especially since the control module can be removed from the pump and mounted on the wall. I told him the MaxFlo would suffice, but yes the removable control module was the big selling factor for that pump. He was saying that both pumps would be very comparable in energy efficiency, and that the Ecostar would only need to ramp up RPM for the initial push of water to the solar on the roof. After that, he said something along the lines that it could be ramped back down a little b/c the solar would already be primed and the centrifugal force would be keeping the water going through the solar. I had mentioned what I learned here about having enough flow to keep the VRV closed which could be ascertained by hearing if air was getting sucked through the system and bubbles/air being produced in the pool return lines. He said that even if there are some minor bubbles, it's okay as the solar doesn't need the same RPM to keep it flowing through there, but rather just initially.

Does any of this sound legitimate? I never read/heard this about being able to ramp down the RPM a little after getting the solar primed. In the summer/swim season, I anticipated having to increase the RPM during the time solar is on, and especially during the time the solar and Polaris are on.

With the Maxflo, this would mean that I could only have 3 programs. Again speaking about during the swim season, my 1st speed would have to be higher b/c when it comes on the solar would most likely be on. 2nd speed would have to be even higher b/c it would have to cover the solar & Polaris. The 3rd speed would probably be the same as the 1st speed b/c solar would still be on.

I guess a benefit of the Ecostar would be that I could have 8 programs (way more than necessary). I could use 5 programs such as: 1) on w/out solar, 2) solar on, 3) solar & Polaris on, 4) solar on, Polaris off, 5) solar off. This would still leave me 2 more programs. If what this guy says is correct, that would mean that I could add in another speed for solar priming and then backing down.

The situation for the Ecostar vs. Maxflo again comes down to paying more for a larger pump that has more than enough programs and has the huge convenience of allowing me to remove and mount the control module on the wall, vs. the Maxflo with 3 programs, will cost less up front, and should be slightly cheaper than the Ecostar to own/operate over the pump's life.
 
bbrock said:
Does any of this sound legitimate? I never read/heard this about being able to ramp down the RPM a little after getting the solar primed.
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Yes and No. Priming may require more flow rate than normal operation because air has to be pushed out of the pipes and there is a critical flow rate to do this. Once primed, you can sometimes reduce the flow rate/RPM but reducing RPM too low can reduce the pressure at the VRV and if it is below 0 PSIr, the VRV opens at which point you lose prime in the panels and head loss jumps up by the height of the panels (i.e. static head). This jump in head loss could stop all flow rate because there is a maximum lift that is a function of RPM. But at a minimum, it would reduce flow rate significantly affecting the heat transfer of the solar panels. So it is imperative that the panels maintain prime and the only way to do that is to maintain sufficient RPM so the VRV remains closed.

However, depending on the return side plumbing head loss and the height of the VRV, the critical flow rate (~40 GPM) may higher or lower than the flow rate required to maintain enough pressure on the VRV to keep it closed. In order to get even lower RPM, you can lower the height of the VRV so that is in only a few feet above the supply side plumbing.

As for the other stuff, yes the EcoStar has more speeds and more flexibility. It is your decision if that is worth the extra cost.
 
Tx Mark.

Sounds like that unless I lower the VRV, determining how much I can reduce the RPM after the solar us primed will be a balancimg act being keeping them primed and the VRV closed. I think I noted that u said the solar may only need about 30 GPM, but looks like here u estimate maybe 40 GPM. Not a big difference, so I assume possibly at somewhere between that. Looks like a flow meter would help here, but one thing that this new pool tech had stated was that some check valves have a flow meter on them. He's going to get a flyer of the valve he is talking about and email it to me, & if that is the case it sounds like something that may be useful. I would have to research that more if such valves exist and work.

Would you recommend changing the position of VRV regardless? It sounds as though I could literally have it just a foot or two above my pump area/pool equipment box on the solar return line. Would a section be cut out of the return pipe and then a T section made w/ a VRV? Got a pic? What would I do with the old VRV? One of the pictures in this thread showed mine had a check valve type design.
 
A flow meter won't really help very much, as what matters is pressure/suction, not flow. While pressure and flow are closely related, you can't know their exact relationship, so knowing the flow rate won't help. What can help is having another person to climb up onto the roof and tell you what the VRV is doing while you are adjusting the pump speed.

I wouldn't bother with moving the VRV, but if you are fanatical about saving electricity it is something that can be done and can save some electricity. Keep in mind that if you lower the flow rate too much you can create enough suction at the panels to collapse some of the tubes of the solar panel from the suction, which makes the panels far less efficient. So there are some hard limits on how much you can improve things.
 
Flow meter is not really needed because the target flow rate is somewhat unknown. Trial and error is the best way to do that. But if you really want one, Dave sells one on TFTestKits. http://tftestkits.net/Flow-Meters-and-PSI-Gauges-c12/

The 30 GPM was for the panel size and not priming. You don't want to drop the flow rate to lower than about 0.1 GPM/sqft or the panel efficiency will start to drop. So you may not want to lower the VRV because of this.

However, if you still want to lower the VRV, I would not use a standard check valve like you are now but use one of these:

p_part_vacuum_breaker3_d.gif


You can install in in a tee in the supply pipe instead of the end of the header.
 

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Tx Mark and Jason for your last posts. Sounds as though moving the VRV may not be worth the trouble.

I am looking at sites to purchase either the MaxFlo or the Ecostar. Seem to find the best prices here, plus no shipping, or tax to CA (http://www.poolcleaningparts.com/hayward-maxflo-vs-sp2302vsp-variable-speed-pump.html). One concern though with regards to the MaxFlo is the union connection size. It uses 1.5"x2" unions. The Ecostar uses the 2"x2.5" connections. With 2" plumbing, would the smaller union connections of the MaxFlo negatively affect anything?

I thought about this when I re-read the posts above about the larger Jandy 2"x2.5" valve vs. the 1.5" x 2" valve. If my system is 2" plumbing, could the flow rate right at the input and output be affected by 1.5"x2" connections?
 
Right on. Thanks Jason.

I went back to Hayward's Energy Savings calculator (https://www.hayward-pool.com/shop/en/pools/EnergyCalculator) b/c I just really question if the MaxFlo could save me more than the Ecostar. For comparison sake, I set the flow on the calculator to a point that I could achieve approx. 50 GPM. As best as I could tell, I see that in order to achieve the same GPM, the MaxFlo will have to run at a higher RPM than the Ecostar. Hence, it will be using more watts. The MaxFlo at 2300 RPM uses 500 W to produce approx. 50 GPM. The Ecostar at 1800 RPM uses 354 W to produce 50 GPM..

Even though the MaxFlo could work, if it has to work harder to achieve the same results as the Ecostar, then it would be less efficient. And, any upfront savings cost (approx. $215) would eventually be lost. Right?

The other criteria I input for the Hayward calculator were: 12 mo. pool season, $0.32/kWh electric cost, run time 7 h/d, 0.75 single speed pump, 20k gal. pool size (as I can't use 19k gal.).
 
bbrock said:
Even though the MaxFlo could work, if it has to work harder to achieve the same results as the Ecostar, then it would be less efficient. And, any upfront savings cost (approx. $215) would eventually be lost. Right?
Click to expand...
I don't know where they get those numbers but based on actual measurements from the APSP (see my spreadsheet in sig), the energy use difference is not as much. For Curve-C, 2" pluming, 50 GPM is the following for each pump:

EcoStar: 1785 RPM @ 370 Watts

MaxFlo: 2150 RPM @ 401 Watts

That is a difference of only 31 Watts. At $0.32/kwh, that is ~$0.01 per hour of run time. So to make up $215, that would be 21,500 hours of run time or 5375 Days (4 hours per day) or ~180 months of operation. It is unlikely that the pumps would last that long. I run my pump only 4 hours per day so you should be able to do the same.
 
Mark, great analysis! Thanks!

I used 50 GPM as an example b/c I assumed, regardless of the 2 pumps, in the midst of summer, that that would definitely be high enough to get it to my solar and run the Polaris at the same time. If it is, then I could probably back down the RPM a little before and after the Polaris runs. If I have or decide to run the VS pump 8 h in summer, based on your analysis, looks like it would take 90 mo., or 7.5 years, for the MaxFlo to end up costing slightly more than the Ecostar.

We have similar size pools in that mine is 19k gal. But, you are really able to get away with 4 h pump time, even in the midst of summer, and have an acceptably filtered and solar heated pool? I recall that you mentioned you use a pool cover, which would help keep in the heat. At this time, I don't use a pool cover, but I had anticipated this next summer running the pump again 6 h, maybe up to 8 h, to maximize the solar heating and filtration b/c I would be able to run the VS pump at a lower RPM vs. my existing single speed. I thought with a VS pump that the lower the RPM, the longer the run time to achieve the same as a SS. In the off season w/ no solar, I assumed I would even have to run the pump longer b/c I could get away with, just guessing, 30 GPM when the Polaris is not running.
 
4 hours is plenty for filtering in a residential pool. But solar heating often benefits from longer run times during heating season.

You need longer run times to achieve the same total number of gallons moved, but that is not an important criteria here. Ignoring solar and pool cleaners, the main use of run time is to skim as much debris off the surface as possible, while filtering requirements are minimal when nothing is going wrong.
 
Also remember run time has very little to do with water quality. The article in my sig shows that there is little improvement in water quality after about 2 hours. The only mandatory run time requirement is for chlorine distribution. Everything else is optional. I could get away with even less run time if my SWG was bigger. The ONLY reason I run for 4 hours is because of the SWG. Even solar does not require that much run time since I use a cover so I only need about an hour of solar to get back to 86 F and that is enough for skimming and for the cleaner as well. You are in the next town over so I would be surprised if you could not do the same as me.
 
Tx Jason and Mark for the replies.

Mark, while I may be able to achieve the same results as you, I think in order to do that I would need to use a pool cover. As I mentioned, I don't use a cover. While I know it would save me $ on utilities (water & electric), the inconvenience of using it would pose more of a problem. Currently, I enjoy being able to take a quick dip. A cover would be a PITA to deal with to do that. Removing a section of my Baby Barrier pool fence, pulling back/out a pool cover that would probably have debris on it, netting out the debris, taking a quick dip, and then reversing the steps would probably make me use my pool less than I do now. Probably someday in the future I will get a cover, but at least not right now.

Turning back to the pumps, even if I ran the pump 8 h/day in the on season, would you say that the MaxFlo is still worth it?

Mark, in post #2 here http://www.troublefreepool.com/thre...-or-V-Green-165-Which-is-best-for-this-config you stated that the MaxFlo and Superflo "will not automatically increase speed when solar is engaged like the other will." Did you mean that the Tristar, or its equivalent Ecostar in my case, does have that capability? I searched the Ecostar owner's manual and have a call out to the one Hayward tech. support rep. that seems to be more consistent/helpful than the others about this matter. No where was this mentioned in the Ecostar owner's man. If this is a feature, that would be pretty cool. I am not sure though if the technology is there yet for it to know/be able to automatically sense when the solar is on and adjust itself accordingly. If this is a feature, could that tilt the decision in favor of the Ecostar, as I would be able to really fine tune my RPMs?
 
You are aware that in California/Livermore there is a drought and if you don't use a pool cover you could be fined.

http://www.cityoflivermore.net/civicax/filebank/documents/9804/

This was my solution to the cover issue: http://www.troublefreepool.com/threads/57594-DIY-Solar-Cover-Roller


As for solar, the pumps will only change speed on solar if you have a controller which will do that. None of the pumps do that on their own. The new versions of the MaxFlo and SuperFlo do have the capability to be controlled by an external controller but again, you have to have a controller which supports this or buy one.
 

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