Pool pumps suck...

Aging GeezerAging Geezer Registered Users Posts: 8
Pool pumps suck a lot of electricity. I recently found out how much. We had a 20 year old Hayward pool pump. It worked great. Every 6 or 7 years I would have to replace the pump motor, when the old one would get noisy. Never thought much about it. I looked into more efficient pool pumps recently, when I realized that the newer variable speed pumps use a fraction of the power that the older and even some current manufacture pumps use. This is one of the several guides I used.

http://www.poolexpress.com/pool-pump-reviews?gclid=CKeOoNWW4KgCFcgZ2god4GKNJA

I went with the Pentair 011018 IntelliFlo Variable Speed Pump. Found it online for around $850 shipped. My first electric bill with the new pump was $30 less than the previous month. This is with the unit running @ 1300 RPM. 24 hours a day, as opposed to the other unit running full speed (only speed) for 8 hours. Anyone thinking about a new pool pump, this is a fantastic choice. I haven't had any issues with water quality. And it's almost silent. This is a huge energy saver as far as I am concerned. I hope this helps someone.

Dave.

Comments

  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Pool pumps suck...

    Very interesting, but I do have to wonder about some of their numbers - - - the very first pump listed. is rated @ 2 HP, yet only uses 138 watts:confused:
    And that type of thing continues on down the list. Hummmm, wonder if anyone yet makes a pump that actually produces more electricity then is consumed? :p
  • solar_davesolar_dave Solar Expert Posts: 2,343 ✭✭✭✭
    Re: Pool pumps suck...

    I have an Pentair pump as well, These are VFD based pumps and do operated at less wattage than the older 2HP counterparts. The flow rates are acceptable. I have mine only running about 4 hours a day and is adequate to floor clean the pool with some light brushing occasionally. The real key to these would be to have the programmable controller installed so the pump can run full force for a short period of time to do skimming and in floor cleaning and then set back to low flow mode for filtering and stirring for a longer period.

    In the hot AZ sun and water temps in the 90's, stirring is critical to keep an algae bloom from occurring. While I don't have a salt water system, the length of pump run is directly proportional to that sanitizing systems effectiveness, this would be ideal for the low flow mode of these pumps. I have found that a one step oversize from the manufacturers recommendation diatomaceous earth (DE) filter system is superior to any other method of filtration. It lowers the pumps filter resistance. It is then pretty clear when a backwash of the filter is needed just from the sound of the pump motor straining. It also scrubs the water to a crystal clear consistency.

    On my previous 2HP pump with a sand filter I struggled all summer with the pool to keep in nice, while having to use large doses of chlorine to hold the algae at bay. It got to the point of several 24 hour runs per season with large does of shock. I have not had to do that once this season since the change out.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    Re: Pool pumps suck...

    The point should be made that pumps draw there load based on the impellers, not the motors rated HP for fixed frequency pumps ( just about everything sold ).

    The VFD units do use less energy, but its because they pump less water.

    Another option that is half the cost is a 2-speed motor, run at low-speed for filtering, high speed when your running the pool vacuum or other accessories

    Most pools will work fine with a 3/4hp pump and matched impeller, pool installers through install 2X over sized pumps almost 100% of the time, there thinking, better to much than to little, the customers never understand the math of GPM or exchanges per day, I'm thinking neither do the pool installers.

    The VFD are nice, but one can get the same savings by just using an appropriately sized pump for 1/4 the cost
  • Aging GeezerAging Geezer Registered Users Posts: 8
    Re: Pool pumps suck...

    Thanks for the input. These are some interesting points. And If a smaller pump can be used at 1/2 the cost, one can only wonder why does a pool builder use the larger one. It seems like his profits would be higher by using the smallest pump they could get away with. I just know that the old pump was a hole in the ground, that I was pouring a lot of money into, in wasted energy costs. Also the lower speed operation, should help prolong the motor life. The single speed motors would start to get real noisy after 6 or so years and need replacement. I too, doubt some of the data on the comparisons, but I cant argue with the results. The water was not flowing near as fast with the new pump, but a little re valving and the circulation returned. The power bill is $30 less a month with this little addition. I'm new to this solar stuff and the conservation that goes with it. But I'm making progress. The July 2010 electric bill, from Peace River Electric was $266. The July 2011 bill, with 6KW solar, solar water heater, and variable speed pool pump was $70. I really think I'm headed in the right direction.
  • solar_davesolar_dave Solar Expert Posts: 2,343 ✭✭✭✭
    Re: Pool pumps suck...

    What the Guppy says is true assuming all parts of the system are equal, like impeller design. I think these Pentair do have a better impeller design. Also many people run the pumps long to get the stirring needed to minimize algae growth by reducing stratification of chemicals and in the case of salt water sanitizer to get that system to be effective. This is where a VFD pump shines. It can run for extended periods at very low power draw to accomplish the required stirring.

    And Geezer you are headed in the right direction. Conservation always pays off more than PV watts.
  • a0128958a0128958 Solar Expert Posts: 316 ✭✭✭
    Re: Pool pumps suck...
    ... The VFD units do use less energy, but its because they pump less water.

    Another option that is half the cost is a 2-speed motor, run at low-speed for filtering, high speed when your running the pool vacuum or other accessories

    ...The VFD are nice, but one can get the same savings by just using an appropriately sized pump for 1/4 the cost

    I just went through this exercise for my pool.

    My single speed 2.2 THP filter pump motor stopped working due to old age. It was pumping at about 70 gpm at 3450 rpm at about 1900 Watts. I was running it 6 hrs/day, resulting in turning over about 85% of the 30 Kgal (the size of my pool) each day. Total annual kWh was thus about 4200. At 12¢/kWh, that's $500 annual operating cost.

    Knowing that with a 2 speed motor, running at 1/2 the speed I was running at, for twice as long as I was running, this would result in filtering the same amount of water each day, but at 1/4 the energy (kWh), I purchased an AO Smith E-Plus Premium Efficiency 2 speed motor. The 2.2 THP model is B2983. Lo speed is spec'd at 0.28 THP.

    Now I'm running the existing filter pump's new motor in Lo speed, which is half speed, 1725 rpm, giving me about 35 gpm. Lo speed runs at 330 Watts. I've doubled the time the pump runs in order to filter the same amount of water, to 12 hours. New daily energy cost is about 4 kWh/day, which is about 1450 kWh annually. At 12¢, that's a new operating cost of about $170 to filter the same amount of water.

    Net savings is about $330 annually.

    Thinking that I needed to wait until my single speed pump broke before replacing it with a 2 speed pump in order to make the pay back reasonable, that's what I did. I now see that if the pump itself is in fine shape, the economics of 2 speed motors are so compelling I could have outright replaced a perfectly working single speed motor and still have a payback period of about 1.2 years ($400 / $330). Wish I hadn't waited.

    Parenthetically, I did look at VFD technology pumps. And indeed their efficiency is even better (about 30% more efficient than induction motors). But the cost, at least here in Dallas, for VFD pumps is very high ($900+, not including installation). My electric rate just isn't high enough to make the investment worthwhile.

    Best regards,

    Bill
  • BB.BB. Super Moderators, Administrators Posts: 29,497 admin
    Re: Pool pumps suck...

    I believe (at least part) of the energy savings with the VFD is the use of Permanent Magnet Motors (typically synchronous) vs Induction Motors (probably accounts for the extra costs too).

    Induction motors generate a magnetic field in the armature (rotating core) from the field coils. That takes electrical energy to create the field (20% or more?).

    Permanent Magnet motors do not need that extra energy to create the rotor's magnetic field and therefore are more efficient. The VFD (probably) helps to start the PM motors (by starting near 0 Hz, then ramping up frequency). Synchronous motors need help to get turning (little starting torque) if hit with 60 Hz right at start.

    Electric Motor Wiki

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • a0128958a0128958 Solar Expert Posts: 316 ✭✭✭
    Re: Pool pumps suck...
    BB. wrote: »
    ... energy savings with the VFD is the use of Permanent Magnet Motors (typically synchronous) vs Induction Motors (probably accounts for the extra costs too).

    The VFD technology motors are 30% more efficient than induction due in part to 3 things: permanent magnet generated field, optimized power frequency as a function of rpm, and construction efficiency techniques also used in induction motors advertised as 'hi efficiency.'

    The economics for VFD motors improves if you can replace more than one single speed motor with a VFD motor. I.e the VFD motor serves as the filter motor, the spa motor, the waterfall motor, etc. Unlike a 2 speed motor, the VFD can be set to many different speed settings to serve whatever function is needed.

    The expense of a VFD pool pump also comes from the marketing strategy (Pentair in particular) of including a control/timer system as part of the pump. This way you don't have to spend more money to install an automation controller for the various functions you want the VFD pump to do (i.e., setting up a schedule for different speeds for filtering, cleaning, waterfall action, etc.) can all be done with the electronics on the VFD pump). The marketing strategy is make it so it's just one purchase - the pump - that can universally be dropped in without other (equipment) expense.

    In actuality, when you purchase a VFD pump (particularly Pentair), more than likely you're in essence purchasing a control (timer) system too. If you already have a controller (i.e. Jandy's AquaLink), then you're purchasing duplicate capability with the motor. There are exceptions to this strategy (i.e. VFD motors with external, 'hanging-on-the-wall' electronics). But for the most part, if you just walk into a retail pool store, what's offered for VFD pumps is units with the control (timer) capability included.

    The advertising for VFD pumps is pretty slick. Often the baseline compared to is running the old single speed motor 24 hr/ day, and thus cutting the time down to just one turnover of water, with the efficiency of a VFD, makes for "$1000 or more savings each year."

    Interesting also, if you just casually walk into big name pool retail outlets, odds are excellent they won't have 2-speed motors 'in stock' (you can order them though). In stock inventory is limited to single and VFD motors. The reason there's no 2-speeds in stock is you need further investment for a control system (generally). It's interesting to note that the common pool owner doesn't have a control system. Or at least there's not enough owners with a control system to warrant stocking 2 speed motors.

    Probably the biggest 'rap' against VFD pumps, other than cost, is warranty. Most offer just a 1 year warranty, standard like the single speed units. The big name VFD pumps, like Pentair, also don't make any piece part replaceable. If something goes wrong with the built in timer / controller, you have to replace the whole motor portion of the pump. At retail in particular, not inexpensive.

    I think there's little debate that VFD pumps are impressive for their versatility and for the operating cost. But unless your kWh cost is 20¢ or more, you're going to need the VFD pump purchase to hold up for a number of years to just break even.

    Best regards,

    Bill
  • bmetbmet Solar Expert Posts: 630 ✭✭
    question on types of chemicals

    Sorry to go off topic here, but since there is so much knowledge of pool systems here, I was wondering if anyone has thoughts about using hydrogen peroxide as a chlorine replacement. My sister has done this on small scale with an above ground pool, but the peroxide is more damaging to the filter than chlorine. Peroxide sounds less harmful than chlorine, but I've no experience with the commercial versions of these chemicals.
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: Pool pumps suck...

    a0128958,
    i believe one of the other moderators merged bmet's question to this thread on pools.

    bmet,
    i wouldn't use too much of it if at all for it is corrosive. just like chlorine it'll turn your hair lighter and not 1 hair at a time either.:roll:
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,662 ✭✭✭✭✭
    Re: question on types of chemicals
    bmet wrote: »
    Sorry to go off topic here, but since there is so much knowledge of pool systems here, I was wondering if anyone has thoughts about using hydrogen peroxide as a chlorine replacement. My sister has done this on small scale with an above ground pool, but the peroxide is more damaging to the filter than chlorine. Peroxide sounds less harmful than chlorine, but I've no experience with the commercial versions of these chemicals.


    We use it in our hot tub. Drain into garden. Very safe after 1 hour. Google the Chofu Hot Tub heaters. The same concept can be used to clean water tanks if they have sat too long. I liked the post on the VFD from both Bill's. The controllers seem too fragile to consider this offgrid where failures are worse than tried and true. Add a 5 year warranty and I might look!
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: question on types of chemicals

    There is also a salt-based chlorination system you could look into. From what I've read most of the salt is removed before the flow re-enters the pool so its not like swimming in the sea. Chlorine products are still produced by the system, but not the type that irritates eyes and has a strong chlorine smell.

    http://en.wikipedia.org/wiki/Salt_water_chlorination
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • TheBackRoadsTheBackRoads Solar Expert Posts: 274 ✭✭✭✭✭✭
    Re: Pool pumps suck...

    FWIW.. A friend a few years ago said that they just dump in a bunch of salt (water softener crystals) and let it dissolve over a few days and that's all they do for their pool... :roll:
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