Swimming Pool Blog
Rob Cox April 09, 2016
Pool Pumps can be energy wasters, especially when inefficient single speed pump motors are used.
Or when the pool pump runs for too long each day, or when the water is not balanced and sanitized properly.
Today's blog post is a recap of pool pump energy usage, and how you can save pump electricity, energy and money, while making your pool more ecofriendly at the same time.
Sure you can install an energy efficient pool pump, but there are other ways to reduce pool pump energy use.
Ten ways to reduce the amount of energy consumed by your pool pump.
- REDUCE RESTRICTIONS: Your pool pump has to overcome vacuum and pressure restrictions, and attempts to balance or straddle these two forces, at a point between the pump curve and system curve. Or said more plainly, the resistance that the pump must overcome is in proportion to the amount of Work the motor has to do. 2 inch plumbing is used on larger pumps, because the larger diameter has less resistance than 1.5 inch pipe. Larger pool filters are also less restrictive than smaller filters and run with lower filter pressure. Check valves, directional valves, chlorinators or purifiers all add restriction, as does a pool heater. Finally, the fewer bends in the pipes, to and from the pool, the better. Every bend or turn in the pipe adds resistance to the system. Total Resistance, as seen in a pump curve shown to the right, is a measure of all of the pipe, fittings, and other equipment (filter, heater, chlorinator, valves) resistance. Most pools are in the 20-40 ft of head, but some systems can run higher. Put even more plainly, if the plumbing pipe size can be increased, or redesigned for fewer bends and twists, and if unnecessary equipment is removed, or if the filter size is increased - these will reduce the Work for your pump motor, which will then need fewer amps, to get the work done.
- RUN THE PUMP ONLY AS NEEDED: You have to be careful here, because if you are too skimpy with the energy usage, you'll end up paying much more in chemicals and filtering to bring the water back to good condition. But, you can experiment with how much time is needed for your pool to stay clean and clear, at any given time during the season. You will need more filtering when it's hot, perhaps double the amount during the hottest summer months, than you need during the cooler shoulder months. The actual amount needed for any pool depends on the efficiency and effectiveness of the pump and filter system. Pools with undersized systems will need to run the pump longer than pools with (larger) systems that have more effective filters and higher flow rates. Most pools are originally designed to turn-over all of the water in a pool within an 8-hour time period. For this reason, most pools should operate the pump at least 8 hours per day, up to 16 hours during periods of high use or high temperatures. Some sunbelt pools with good systems can get away with 4 hours daily during the off-season, but only when water temperatures are below 60 degrees. If you spend the time to experiment with your timeclock over the course of a week, you can find the tipping point where the pool starts to look a little hazy, not quite as bright and clear (all else being equal). Then set your timeclock for a few hours more than that cycle (you do have a timeclock, don't you?). For most pools it's a good idea to over-filter the water just a bit, so I usually recommend 12-15 hours daily, during pool season, but some pools can get away with less.
- USE A VARIABLE SPEED PUMP: Variable speed pumps use lower speeds to consume less energy. When you reduce impeller speed (RPM) by half, you reduce the amperage required by 8 times! Basic models like the Superpump VS or Max-Flo VS have several speed options, which are pre-set. Full-featured VS pumps like the IntelliFlo or EcoStar are able to sense the required pressures and achieve a balanced harmony with the perfect impeller speed to get the job done. Variable Speed pool pumps can reduce energy consumption by 50-80%, so payback on their higher purchase price comes within a few years. Energy Efficient VS pool pumps have another attractive quality in that their motors are quiet and cool permanent magnet motors, which last longer than traditional induction motors.
- USE A TWO SPEED PUMP: Two Speed pumps (also called Dual Speed) are an improvement over single speed pumps, and can reduce energy use by 30% or more. Problem is, you also need a two speed timeclock, and add an extra wire from the clock to the pump, as the fourth, low-speed wire. This increases the cost to such a point that you may as well just buy a VS pump, which will have at least 3 speeds, contains its own timeclock, and uses the permanent magnet motor.
- USE A BIGGER FILTER: And/Or a more effective filter. A pool filter that is more effective (like a DE filter) is so efficient at trapping dirt that less filter pump run time is possible. And a bigger filter is also going to have greater dirt trapping ability, but perhaps more importantly will have less resistance than a smaller filter. Running at lower pressure, the larger filter is less Work for the pump to push water through.
- USE A SMALLER PUMP: A lot of people don't know this, but not all 1 hp pool pumps produce the same amount of flow and pressure. There are medium flow, high flow and very high flow pumps. A 3/4 hp Whisperflo pump produces about the same flow rate as a 1.5 hp Superpump. Or a 1 hp Challenger pump can produce the same flow as a 2 hp Super Flo pump. A smaller pump horsepower translates to lower energy costs, because they use fewer amps. Replacing a medium-flow high-hp pump with a high-flow low-hp pump is what I'm talking about.
- USE ENERGY EFFICIENT MOTORS: Most pumps that you buy online, or installed by a builder are using 'Standard' motors. But if you were to swap out a dying motor with the Energy Efficient (EE) or High Efficiency (HE) equivalent pump motor, you could reduce amp draw by 25%. This is done by using improved design concepts and materials that result in lower electrical loss.
- USE A SLIDE VALVE: If you have a choice in the matter, for sand and DE filters with sidemount valves, the Slide valve, aka Push-Pull valve has less resistance than a multiport style valve, especially in the 2 inch size. Cartridge filters, on the other hand, have no filter valve at all, and also can be a way to reduce filter resistance and motor work.
- MAINTAIN BALANCED WATER: Giving the pool chemistry constant attention will prevent water problems from growing into something that requires running the pump longer to restore the water quality. Good water balance and sanitation practices reduces the need for additional filtration.
- USE HELPER SANITIZERS: When your water is really sanitary, there is less work for the filter to do - fewer particles to remove from the water. Adding a secondary, or supplemental sanitizer (as I like to call them) like Nature2 or Ozone, or even using Clarifiers or Enzymes, can reduce your filtration demand, allowing you to run the pump less, while still keeping the water clean and clear.
For expanded information, and to figure out how much energy your pool pump uses, see my earlier post that inspired this one: Costs of Running a Pool Pump