Is variable speed pump worthwhile on legacy pool

GMS1

0
Oct 14, 2014
14
Huntington, NY
Hi Everyone,

So I have a legacy 30,000 gallon pool with 2 skimmers and 1 main drain. All 1.5 inch plumbing with Hayward DE 4820 filter, an old Jandy Lite 2 heater, and a chlorine tablet feeder.

Our existing two speed pump seems to be overheating on the high speed windings, probably due to a short. That is a Hayward SP2610x15, a little over 9 years old. We seldom used the low speed as we found the flow rate way too slow to keep the pool adequately chlorinated. A clean filter runs 18-20 psi and flow basically stops at 25 psi. Based upon a number of different approaches, we estimated roughly 60 TDH. To be frank, the low speed only had value on opening the pool and vacuuming up all the debris and sand that always seems to accumulate during winter (Loop Loc cover combined with high winds, pavers and sizable tree canopy).

We believe we get about 50GPM on a clean filter, so the pool water turns over every 10 hours on the high setting. We try to run it 5 hours overnight when we get cheaper electric rates. That seems to be adequate to keep the water quality and chlorine levels at decent levels.

So my question is, should I even consider a variable speed pump for a replacement or just swap out the motor for the same model. That probably runs $400 vs $1500 or so for VSP. The old motor is 1600 watts at high speed and our electric rate is about 20cts per KWH.
 
Good news - pool turnover is a myth. A VSP usually pays for itself in first year or so if you can embrace the method that many of us use... running as slow as possible, 24/7.

My VSP uses ~150 watts running 1300 rpms now.

Just remember, run your pump to do these things:
1) Skim the pool well
2) Filter fine debris
3) Run heater/SWCG/tab feeder

I won't get into it here, but tab feeders are not recommended due to the ever-increasing CYA they add to the pool.
 
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Hi Everyone,

So I have a legacy 30,000 gallon pool with 2 skimmers and 1 main drain. All 1.5 inch plumbing with Hayward DE 4820 filter, an old Jandy Lite 2 heater, and a chlorine tablet feeder.

Our existing two speed pump seems to be overheating on the high speed windings, probably due to a short. That is a Hayward SP2610x15, a little over 9 years old. We seldom used the low speed as we found the flow rate way too slow to keep the pool adequately chlorinated. A clean filter runs 18-20 psi and flow basically stops at 25 psi. Based upon a number of different approaches, we estimated roughly 60 TDH. To be frank, the low speed only had value on opening the pool and vacuuming up all the debris and sand that always seems to accumulate during winter (Loop Loc cover combined with high winds, pavers and sizable tree canopy).

We believe we get about 50GPM on a clean filter, so the pool water turns over every 10 hours on the high setting. We try to run it 5 hours overnight when we get cheaper electric rates. That seems to be adequate to keep the water quality and chlorine levels at decent levels.

So my question is, should I even consider a variable speed pump for a replacement or just swap out the motor for the same model. That probably runs $400 vs $1500 or so for VSP. The old motor is 1600 watts at high speed and our electric rate is about 20cts per KWH.
A Nidec NPTT165 motor, with a GO KIT 3, will turn that pump into a VSP. You can then dial in the speeds you need.
 
So yeah, this is what I'm trying to wrap my head around. If I run a VSP at 150W for 24hrs that's 3.6kW at about 20.5cts per kWH daily rate, which is 74cts a day. If I run the legacy pump at 1600W for 5hs that's 8.0kWh but the overnight rate here is 12cts per KWH or about 96cts a day. So I save 22cts a day. The pool season here is May to Oct, about 150 days. So am I right that the electrical savings only amounts to $33 a year? I can see how the savings might be more in a hotter part of the country with more pool days.

On average we use about a half pound of chlorine tabs a day. It's not a heavy use pool, primarily for weekends. We had the liner replaced 6 years ago and the steel underneath was in very good shape for a 20 year old pool, which is part of the reason I am not in a rush to switch to salt water.
 
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If your existing pump handles the pool functions in 5 hours, so will the VS.
Excluding the tab feeder thing. We do not recommend those so it can create an issue. Better off to use a floating chlorinator. Saves your pool equipment.
 
So yeah, this is what I'm trying to wrap my head around. If I run a VSP at 150W for 24hrs that's 3.6kW at about 20.5cts per kWH daily rate, which is 74cts a day. If I run the legacy pump at 1600W for 5hs that's 8.0kWh but the overnight rate here is 12cts per KWH or about 96cts a day. So I save 22cts a day. The pool season here is May to Oct, about 150 days. So am I right that the electrical savings only amounts to $33 a year? I can see how the savings might be more in a hotter part of the country with more pool days.

On average we use about a half pound of chlorine tabs a day. It's not a heavy use pool, primarily for weekends. We had the liner replaced 6 years ago and the steel underneath was in very good shape for a 20 year old pool, which is part of the reason I am not in a rush to switch to salt water.
Have you checked your salt level? You would probably be surprised at the level. Any sodium/chlorine combination, hypochlorite, tri-chlor, di-chlor, has been adding salt to the water. Human tears are about 3X as saline as the levels needed for a SWG.
 
Checking the salt levels is a good point. We've been pretty happy with the pool economics. We figure our operating cost is roughly $100 a month or $500 a season. Probably $30 electric, $50 tablets, and $20 in other chemicals (DE & Borax). We only need to adjust alkalinity and calcium at the opening (7 lb DampRid unscented refills work well, they are pure calcium chloride and we get cheap sodium bicarbonate at the club stores). Might be interesting to figure out if the monthly cost of SWG makes sense at our electric rates.

BTW, I think the pump motor is fine. Yanked the start/run capacitor, tested it, and it's blown. Getting a replacement on Amazon for $15.

FWIW, my newest neighbor owns a small biz and during Covid got some PPP loans. Installed a $80K inground with all sorts of grottos and water features. It's like a water park over there, he could probably charge admission! Your tax money at work.
 
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