|
07-18-14, 02:06 AM | #1 |
Journeyman EcoRenovator
Join Date: Jul 2014
Location: Austin, TX
Posts: 314
Thanks: 39
Thanked 50 Times in 45 Posts
|
Save electricity with a 2 speed pool pump
Great website, I'll try to contribute with what I know.
Swimming pools are awesome, but their upkeep requires a lot of power. Most pools are built with over sized pumps that use more power and waste energy because of head pressure and pipe resistance. For instance I have a 10,000 gallon pool it is common to see builders match up 1.5 hp motors for this size. I currently run a 3/4 hp pump that moves enough water for 4 return jets to break the surface of the water or move back the pool cover. In theory because I'm moving half water than the 1.5 hp I would need to double my run times. In practice I get by running the pump intermittently for 4 hours a day. My current project is to replace my single speed 3/4 hp with a 2 speed 3/4. Low speed is 1/2 the rpm and flow but uses 1/8 electricity. This reduction is because the head loss from pipe resistance is minimal at lower speeds. I currently have a replacement motor on order, Ao Smith Century B2890. This motor line has a more efficient low speed than traditional motors. Price for the motor shipped is $270 and the energy savings should pay for itself within the first year. |
07-18-14, 12:12 PM | #2 |
Administrator
Join Date: Aug 2008
Location: Germantown, WI
Posts: 5,525
Thanks: 1,162
Thanked 374 Times in 305 Posts
|
That sounds like a good idea. How much electricity will that save you per day?
__________________
Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. |
07-18-14, 12:27 PM | #3 |
Super Moderator
Join Date: Jun 2013
Location: SC
Posts: 2,923
Thanks: 172
Thanked 564 Times in 463 Posts
|
Last year I got this pump. On lowest setting it uses 65 watts it is 240 volt .
I run it on low power. I now run it 12 hours a day but it has saved so much power. Speck Pumps - Badu EcoM3V - Variable Speed http://usa.speck-pumps.com/pdf/Techn...coM3V_tech.pdf How many watts does Ao Smith Century B2890 use on low? That is a good price on that motor. Last edited by pinballlooking; 07-18-14 at 01:57 PM.. |
07-19-14, 04:32 PM | #4 |
Land owner
Join Date: Nov 2012
Location: NM
Posts: 1,026
Thanks: 12
Thanked 127 Times in 107 Posts
|
Just power factor correcting the pump can save up to 30%.
But typical 220v motor setups see about a 5% savings. |
07-19-14, 04:35 PM | #5 |
Supreme EcoRenovator
Join Date: Oct 2008
Location: Austin, TX
Posts: 1,154
Thanks: 14
Thanked 257 Times in 241 Posts
|
PFC doesn't offer much benefit in residential.
__________________
To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her... |
07-19-14, 06:46 PM | #6 |
Land owner
Join Date: Nov 2012
Location: NM
Posts: 1,026
Thanks: 12
Thanked 127 Times in 107 Posts
|
Have you actually tested it?
I have seen new digital power meters with an "80% P.F." kwh counter. So even if all my tests were wrong, some day we will all get a shinny new kwh meter and surely they will bill more for whats on the "80% P.F." counter. |
07-20-14, 03:13 AM | #7 |
Journeyman EcoRenovator
Join Date: Jul 2014
Location: Austin, TX
Posts: 314
Thanks: 39
Thanked 50 Times in 45 Posts
|
This site has a very good operating cost comparison of various pumps and their operating wattage. It shows monthly costs between $8-$30
It also has some great info on pipe sizing and head loss. A lot of other factors weigh in with pool pumps but traditionally 1 hp =745 watts. Which can give you an idea of the benefits of proper pump sizing vs oversizing. |
07-20-14, 03:14 AM | #8 |
Journeyman EcoRenovator
Join Date: Jul 2014
Location: Austin, TX
Posts: 314
Thanks: 39
Thanked 50 Times in 45 Posts
|
Energy Efficient Swimming Pools
https://sites.google.com/site/maspooltools/spreadsheets |
08-02-14, 12:25 PM | #9 |
Apprentice EcoRenovator
Join Date: Nov 2013
Location: Moore Oklahoma
Posts: 267
Thanks: 108
Thanked 23 Times in 21 Posts
|
Multispeed PSC motors don't save as much money on "low" and buyign a smaller single speed pump. Currently running a 1/4HP pump on my own pool (uses 250W) for (2) 4hr shifts per day.
|
08-07-14, 08:32 AM | #10 | |
Banned
Join Date: Aug 2014
Location: US
Posts: 150
Thanks: 7
Thanked 5 Times in 5 Posts
|
Quote:
This motor's the real deal true sped with 2 pole/4 pole windings with industrial motor standard rating. A well made AC motor is quite efficient. The motor runs at constant RPM for each setting. I'm looking in the catalog and I see these specs. You might find them to be strange specs, but fan law will tell you that cutting the fan to 1/2 the speed drops the GPH to 1/2 and (1/2)^3 =1/8 the horsepower requirements, hence 1:8 split. 0.75hp/3450RPM 230v 6.0A@1.67 SF 0.10hp/1725RPM 230v 1.0A @1.67 SF Those amps are at maximum allowed overload conditions. I guessed the PF, but I did it so on the conservative side. These motors are heavy and use copper generously, so they're not cheap. 1/6hp @ ~67% (PF at 0.9) 1 1/4 hp @ ~75% (PF at 0.9) These are plug-to-shaft efficiencies. Not bad for something this size. It's at the 67% overload given in the specs, and they're more efficient when they're not overloaded, so you'll probably get closer to 80% to the shaft. AC motors are very reliable, tough and they don't create harmonics. Adding a VFD will just make it much more susceptible to surge damage, reduce efficiency and induce high levels of harmonics into the line. You don't need controlled ramp or a bunch of in between speeds for a pool pump. You'll lose another 10% or so of kW going into it in conversion process in the VFD box. Why the over load rating on motors? It's so you can size it for continuous use at 3/4hp, but have the ability to handle increased load from cleaning attachments and such without the need to actually oversize the motor. It will handle an overload up to 67% for quite some time without issues. If you run a 3/4 hp VFD with and you overload to 1 1/4 hp load for more than a few seconds, it will let the smoke out. Attached picture shows you how a common air handler fan is made multi-speed. Last edited by ICanHas; 08-07-14 at 08:46 AM.. |
|
The Following User Says Thank You to ICanHas For This Useful Post: | stevehull (08-07-14) |
|
|