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Energy Efficient Pool Pump Recommendations?

This is a somewhat personal question - but I'd like to have solid resources in my back pocket as well. Specifically, we are replacing our 24' above ground pool pump. Can anyone make recommendation for an efficient (and affordable) model? Features that matter or don't matter?

I started to research but quickly got in the weeds. It seems like with many other "energy efficient" things out there, the price tag can vary greatly and it's difficult to discern what legitimately might make one more expensive than the other. This is also a question that I get from clients from time to time and I'd like to have a "cheat sheet" or grouping of legitimate links to share with them.

Thanks!

Comments

  • Best Resource on this is way down south in Florida. Lots of pools. Florida Solar Energy Center. FSEC.
  • I just bought a pentair 3/4 HP pump for our pool - quiet and efficient.
  • David ButlerDavid Butler Posts: 3,889
    As you know, pool pumps can be energy hogs, especially if not designed properly. Like the HVAC industry, residential pool designers often rely on rules of thumb, leaving money on the table in terms of operating costs.

    I don't know models, features & prices... but a properly sized ECM pump is going to be a lot more efficient than PSC, but it will cost a lot more. The problem is you need to do friction loss calculations on pool plumbing and filtration in order to size the pump as well as to do any sort of cost analysis. If you're game, I can step you through the process, which might be interesting for others as well. I would ask some questions about the pool and then explain the calcs.

    In the meantime, here are a couple of general tips... A rule-of-thumb turnover rate (# of changes per day) is not likely to be optimal. The biggest way to reduce pump energy is to experiment with the pump schedule to minimize run time without affecting water cleanliness. And keep those filters clean!
  • David Butler yes I'm definitely interested! We have had the proverbial energy hog since we put the pool in 2008.

    We've managed it's usage exactly like you said, running it as minimally as possible without affecting water cleanliness. (we had it on a timer for a while, then the timer broke so we turned it on when the pool "looked like it needed it"). And yes, clean filter makes all the difference in how clean it keeps it!!

    The plumbing is really simple and close-by so it should be an easy case study/calc...unless...I've been toying with the idea of putting in a hillbilly solar heater (we live in rural area so can get away with the moderate-hillbilly look). We have a brown metal pole barn roof about 15' away from the pool, the side of the roof with full sun and southern exposure is 16'x32'. If we're going to do that ever, the time is now...
  • David ButlerDavid Butler Posts: 3,889
    Need to know...
    (a) type of pipe (typically PVC?)
    (b) nominal pipe diameter
    (c) approx. feet of pipe length (supply + return)
    (d) # of elbows
    (e) pool capacity (gallons)
    (f) filtration system make and model **

    ** I'll try to find pressure drop information on the filtration system.
  • Take a look at Hayward's Ecostar variable speed pump. I've tried it in my own inground pool and it has saved a lot of money. The pump runs full time rather than full out for a short time. But the energy consumption at the slower speed is much less than full, so overall it saves money. In addition, the pool stays cleaner because the filtration is more efficient at lower pressures. The disadvantage of this option is that it is significantly more expensive to buy. But I would do it again having seen the difference in long-term energy cost.
  • I design EE plumbing systems for ponds & water features. Often see landscape contractors use pool pumps with high energy loads. Common mistakes that add head pressure to systems include:
    - 1-1/2" diameter piping - you do not need to use the same diameter piping as the fittings on the pump or filter! Need to size piping based on how much you can reduce pipe friction component of the total system head pressure. I start with 2" and often go to 3" when long runs.
    - Use of rigid piping with many elbows & fittings - By using more flex piping we reduce the additional piping equivalent of fittings.
    - Swimming pool filters use sand to strain out the debris from killing water components with chlorine. The small porosity of the sand creates high head pressure. The trend towards living filters and natural swim ponds requires filtration media with higher porosity and less back pressure.
    Matching impeller and horsepower for the desired performance curve is key.
  • David ButlerDavid Butler Posts: 3,889
    As David W pointed out, the pump's performance curve is indeed a big deal. In particular, you don't want to operate at the high end of a pump's range, which Bob alluded to. But sizing too far down the curve (by installing a larger VS pump) is also sub-optimal, and expensive. The shape (slope) of the curve is important as well since our friction loss calcs are just estimates and head pressures will vary between filter cleanings.

    This is not unlike selecting the best air handler for an HVAC system, except in this case the motor is dominant load we're concerned with.

    Since you've already worked out existing pump's ideal operating cycle, we can remove a big uncertainty from the pump selection calcs and design to the more desirable 100% duty cycle. For that, I would need
    (a) the existing pump make and model
    (b) hours per day or week it needs to run to keep your pool clean

    And finally, if you've sub-metered your pump, we can do a much better job estimating the potential savings.
  • I will get it all info together, it may take a bit ( Amanda Tolliver help me help you!)
  • Curt KinderCurt Kinder Posts: 248
    As an HVAC guy I regularly suggest VS pool pumps in the course of audits - faster payback than anything I've got in my toolbox. My own pool has 1.5" piping, so I went with the smaller Hayward for about $600 online. The tunability of VS pumps is a key advantage.

    I'm also sensitive to filter pressure losses - one piece of data I gather at every audit is the indicated pressure at the filter dome. Lose the sand filter in favor of a cartridge model, IMO.

    Beware of items that need a minimum flow, such as chlorinators, heaters, skimmers, etc. Programming different run speeds for different purposes is worth considering.
  • Danny GoughDanny Gough Posts: 185
    Julie, There is a gent named Jeff Farlow who has done sessions at Resnet on this topic. He would be the go to guy for all your answers. I believe he came out of the motor research division of Advanced Energy. He now works for Pentair. I would research past Resnet attendees and look him up.
  • David ButlerDavid Butler Posts: 3,889
    Jeff is actually a member of this group. Maybe he'll chime in now that his name has been mentioned.

    I encouraged Julie to post her system information here so we can go through a "peer reviewed" design here in the forum for the benefit of other group members. It's something that many of us have to deal with from time to time. The hardest part is getting the data.
  • Jeff here. All of the information provided here is on target and solid. I would like to simplify it to say...your best bet is a variable speed pump - period. I can go on for days describing the whys but for simplicity - you'll almost never go wrong with this choice.
    The biggest factor is the power supply available. If you have 230V available, your options are vast. Many above ground pools only have 115V easily accessible. There are now 115V/230V options in smaller (and cheaper) sizes making them well suited for the above ground market.
    Regarding HP sizes for variable speed, the beauty is that it's pretty close to a one size fits most. It's quite safe to say that for a 25k gallon above ground pool, you should never need more that a 1.5 Hp, which is one of the smallest Variable speed version available. The ability to slow the pump down to match the specific tasked needed (filtering, skimming, heating, vacuuming, backwashing, etc.) allows for rightsizing the pump...
  • ...for the job at hand. I totally agree with the cartridge filter over the sand or DE filter for both energy and water savings. Remember with variable speed - run it longer and slower as runtime is healthy for the pool. You wont believe how quiet and how much cleaner the pool. My recommendation is the Pentair SuperFlo VS (p/n 342001) for your application (a shameless plug, but I do feel it's one of the best choices for this application.) Note that these pumps already have built in timers so you can take advantage of TOU rates if applicable. Many utility rebates are available - for a complete list visit: www.pentairpool.com/save-energy/utility-rebates.html . You'll also find cost saving calculators there as well. All things considered, VS might be the cheapest to purchase...it definitely is the cheapest to own and payback is usually well within one or two seasons.
    I can go on for days on this topic but let me stop here and see if this gives you enough confidence to proceed.
  • David ButlerDavid Butler Posts: 3,889
    @Jeff, thanks for chiming in! Lots of good point. No prob mentioning your products (I'm the moderator) since it's responsive to the thread topic.
  • Curt Kinder thank you for the insight. We currently have a cartridge filter and a chlorinator (ironically we didn't use it last year, we filtered and chlorinated "as needed") so I could remove it or at least take it into consideration.
  • I was out of town and swamped for a few days - I do hope to get the system information together this weekend at latest so please stand by. Jeff Farlow thank you for the "shameless plug" (and other info) and David Butler thank you for allowing it. Initially I was hoping for a quick recommendation (like that) and my daughter Amanda Tolliver (who runs my house) wants to buy one right now. Of course, since David suggested it, I totally want to engage in the "peer reviewed" design process!
  • David ButlerDavid Butler Posts: 3,889
    @Julie, I imagine the pump crowd would consider my engineering approaching a bit over the top. As a pragmatic matter, sizing a variable speed pump is less critical than with PSC pumps.

    If you can keep your daughter at bay, I think it's instructive to step through the design process to see where it leads. When it comes to building systems, impatience often leads us astray ;-)