Not every house has one, and they certainly don't provide an essential energy service, but they sure gobble energy.
Interested in hearing your favorite approaches and strategies for tackling these loads.
My grandpa was a "Polar Bear", and swam in the Atlantic in the wintertime. Not everyone has those genes, tho.
Pools are interesting. Normally the run times for the pump and sweep are set by pool maintenance companies not by homeowners. I showed my mother that her pool run times were 6 hours a day - all afternoon and early evening. No one used her pool except me when I came to visit a couple times a year. I set the run times to 2 hours a day starting at 7 am (where I kept mine normally with good water chemistry results). A month later I was visiting again and noticed it running in the middle of the afternoon. I checked the timer and it was reset to 6 hours per day and from 1 - 7 PM, thanks to her pool maintenance company. Told her to fire them and do the chemicals herself.
The system I found that was incredible was Pentair's IntelliFlo system (I don't sell them and there may be other similar ones on the market). It is a variable speed pump motor that runs for 8 hours for what it takes a standard pool pump to run in one hour and combined with a matching filtration system it is amazingly quiet and effective. Oh one thing though, it may not work on older pools (or newer ones) because of the plumbing. We used one on a demonstration house in San Diego for the Extreme Energy Makeover Project a couple years ago at the insistence of SDG&E and it cost $17,000 to replumb the pool to make the system work right. Almost the cost of a brand new pool, but it worked incredibly well. So if you are putting in a new pool, use a system like the Intelliflo and have the plumbing engineered by Pentair or whatever hyper-efficient pool pump company you use to make sure it works properly once it is buried under all that concrete. And who know, maybe your existing pool's plumbing is adequate.
As far as solar heating goes, we learned a lot back in the late 70's when solar pool companies gave a pool cover along with every solar system they installed - that is what kept the pool warm - the cover! I can't for the life of me figure out why anyone would want to heat their pool during the summer with a solar system, it is only good for the shoulder months (April and October) to provide heat (put that in a payback calc and see what you get - nada!). In the summer you want a cool pool not a hot pot anyway, so cover it.
What about black-bottom pools? I experienced one for 10 years. Loved it. Black body radiation from the pool to the summer night sky cooled the pool down more than similar uncovered white-bottom pools. Neighbors' pool temps were in the 90s in the middle of the summer and mine was in the mid 80s! When I covered it with an insulating cover at night the temps went up into the 90s - so I stopped that after my first summer with the pool and only used the cover for the shoulder months and it really helped.
There's a good discussion in this parallel Forum thread.
Not using a solar thermal system allows one to investigate different rate schedules. The house I grew up in originally had gas heat, and we used a pool over, then later my parents added solar thermal to the pool. It was nice finally having a warm pool. The pool cover didn't supply enough heat, nor did the solar thermal, but combined together they kept the pool plenty warm here in sunny California.
When you use power dictates much of the cost for energy on an E-6 rate schedule. If you can cut energy usage between 1-7pm it will work to lower most peoples overall energy bill. For anyone using over $123 or 700kw a month a solar system will pay for itself. With solar PV E-6 really comes into play and the system can be downsized by 1/3 saving the homeowner money. If some falls within those parameters, they owe it to themselves and future to look into a solar system. Most companies offer free quotes.
Why did you have to change the plumbing in the San Diego pool? I just purchased a Hayward Ecostar that essentially does the same thing as the Pentair for an existing pool without any noticeable problems.
But you are right - these new pumps decrease electrical consumption substantially. I estimate my power usage will be less than 1/4. That is with the pump running full time instead of just 8-10 hrs per day.
I thought I would add a couple of things to the conversation. The Pentair variable speed pump has two great options, first it has a ceramic magnet instead of the standard copper wiring. The ceramic magnets once started actually turn in perpetual motion, without much energy draw. Secondly you can run it a very low g.p.m almost freeze control or ramp the baby up to run your spa or waterfall. However it is best to run the normal run time at a low flow rate. The slower the flow the better the filter will pick up the particulates. The old theory was to put a bigger pump to clean better however it would only pancake the filter at the return inlet and would clog the filter causing the filter to only be 20% or so efficient. Just a waste of energy and money. Yes the size of the plumbing return lines and suction lines are important. The more water that can pass in a larger line at a lower flow rate the better the filter will clean and consume less energy and money. In time the pump will pay for itself, also is endorsed by PG&E. If you can afford one it is the best over a two speed for sure. Calif code now calls for a 1/2 hp, 2 speed or variable speed filtration pump on new construction.
If you have a old pool check to see if you have split drains, if not it is a real suction hazard and potential liability, the other important item is the automatic pool cleaner. Two kinds suction and pressure side. Suction side cleaners are also a possible entrapment issue, if making a choice a pressure side cleaner is a wiser and safer choice. (Suction side cleaners suck water into the wall inlet with great force, pressure side pushes water out of the inlet into the cleaner, no possible entrapment issues.)
We have the Pentair system too. We added a very efficient heat pump pool heater and with rates around .07/kwh its reasonable. I like the pool warmer because we tend to swim at night.
The main caveat I wanted to add is this. An energy monitor would probably reduce pool electrical consumption in most cases and, no matter what else you do, it would almost always help reduce power use even more. The reply about the pool company turning up the run time on the pump would have probably ended up in the mom going after them with the broom if she had accurate information on what effect their "more is better" mentality was having on her power bill.
Evan, interesting post.
Tom, Couple things...
From a total resource perspective, your mother's pool clearly consumes a huge amount of energy relative to person/hour use if it is only used a handful of times a year. Every swim costs what, $1000? Examples of grotesque American energy consumption everywhere you turn, in her case she's got little choice.
How you would operate your pool in whatever area of the country you live in is not necessarily how everyone should operate theirs, particularly when considering a pool that only get's used a few times.
Evaporation losses are a huge heat removal mechanism for pools, arguably the largest. The larger the delta t and lower the dew point the greater the BTU loss, so climate zone plays a significant part. Pool covers keep pools warm by prevent this loss, not so much adding solar heat. Frequently used pools may not get covered much. Solar panels can be used not only to heat but also cool the pool at night.
For some, strategically adding or removing heat may actually bring their hours used to energy consumed ratio down. Driving down "cost per swim" means getting the most benefit from the resource. Double your season/useage for less than double your total cost of ownership, seems like positive return from my perspective. Am I looking at this wrong?
Solar panels are a very nice solution for people who may need heat added or managed.
I've got two "pool" clients in Contra Costa County. One is thrilled that he replaced his pool pump with a Pentair variable speed pump. He claims the unit has a 2 or 3 year payback. The thing is really quiet but costs over $1200.
Another client, just up the road, is complaining about her $500 electric bills from her pool with a 1991 2 HP pump and an electrically heated spa. She claims the spa can not be turned off or black mold will grow in the pipes. I'm trying to sell her the above pump. What to do about the spa? She does not want to go on time-of-use rates as she considers them punitive.
I wonder if Tom can tell me how I could determine if the existing plumbing would work for the Pentair pump? How would you tell?
I would like to weigh in. The older pools that use a one pump system used a 1/12 hp or 2 hp pump. It certainly is inefficient in today's standards. The theory was a larger pump was better, like the H.V.A.C systems.
Your client will be best served by at least using a 1/2 hp for the filtration pump and have a pool plumber come in and add a separate pump for the spa. It will not cost much to re-arrange the plumbing at the equipment pad. The heat option would be to add solar for the pool to increase the base temperature, that way if she only has electricity to heat the spa it wont take much more to raise the temperature to 100. If your client has a pool vac she can run the vac off the spa pump. A variable speed pump will do the job if she does not have a vac. The pressure side vac will require a booster pump. She will have relief on her bill with undersized filtration plumbing using the variable speed pump. Remember there is no copper wiring in the pump, it has ceramic coated magnets. Once the spinning action begins it takes very little juice to keep it going. Almost perpetual motion!
George, you'd have to talk to a Pentair rep. A Pentair rep checked out the pool I was dealing with. I'm not sure what tests he did as I wasn't there the day he showed up, but he found out that the drain return was mostly clogged and the return piping wasn't adequate to allow the system to work properly. The system can run both a pool and a spa separately on the same motor/pump. She might want to turn her spa into a Koi pond and get a good above-ground one is she really needs it.
You might need to educate your client. Black mold can't grow in aqueous environments and needs cellulose to grow on like the back side of drywall; there is a black algae common to pools that is typically treated with the proper chemicals and having a chemically-balanced pool/spa. It is a pain to deal with though, when I was a "pool-boy" in high school I spend hours scraping the stuff off with a wire brush on a couple pools, helped my skin diving abilities though. With the exception of deteriorating the gunnite and possibly clogging up pipes black algae doesn't have any health issues that I've heard of.
Good luck, next you are in Chico lets have coffee
Lorin Erlie @916-284-9774 He may not answer and is slow to return calls!