Variable Speed Pumps Explained
There is no question that variable speed pool pumps will save you money and cut down your pump noise, but how do you compare pumps when you have a solar pool heating system? Choosing a pump based on cost, horsepower, or brand alone will result in poor performance or savings at best, and disastrous results at worst.
If you don’t know what a variable speed pump is, it is pretty simple. The motor speed (measured in RPM or revolutions per minute) can be changed, which changes the pool system flow rate and pressure. The higher the speed, the more water flow. Because pool pumps are centrifugal pumps, they obey a law of physics called the affinity law. This law says that the flow rate is proportional to the motor speed, but the energy use is proportional to the cube of the motor speed. For the math averse, this means that doubling the pump speed will result in 8 times the energy use!
More importantly, slowing the pump down by half will result in 1/8th the energy use. In other words, it is better to run your pump at half the speed for twice the time, getting the same overall pool water turnover, and you will still use just 1/4th the energy. In fact, why not run your pump even slower? Operating it at 1/4th the speed will require just 1/16th the energy.
A combination of things happened to make variable speed pool pumps popular in recent years. The cost came down as variable frequency drives (required to vary the speed) became mass produced. A variety of laws and building codes came into effect that required variable or multi-speed pumps for residential pools. Manufacturers worked out the kinks with early VS pumps that caused failures in the drive electronics. These factors combined made choosing a variable speed pump a no-brainer for new pools and retrofits.
Essentially all new VS pumps on the market today have brushless motors that make the pump even more efficient and long lasting. The main differences are the maximum pump horsepower and the electronics, most importantly the external control capabilities.
There are major differences in pump controls that dictate which variable speed pumps are best for solar pool heating systems. The key is to be able to change the pump speed based on what features are running through some sort of automation. This is important if you have water features like fountains, bubblers, or a spa overflow that require a particular flow rate for desirable operation. It becomes critical when you have a solar pool heater (or any heater for that matter), because heaters rely on adequate flow rate for optimal performance. Solar pool heaters in particular perform better when the flow rate is relatively high. Fortunately, with the right controls, we can “dial in” the best speed for solar pool heating panels to optimize performance and balance that with energy use.
Most pumps have integrated timers that control a variety of speeds, but some rely on an external control timer for on-off operation. Some use a combination of internal pump logic and an external time clock to change speeds throughout the day. If you want maximum control, you should select a pump that has either a terrific on-pump interface, robust external automation options, or both.
Some brands and models have proprietary external control cables and logic, which is not necessarily a bad thing. When you have an existing pool automation system it is often preferable to stick with the same pump brand, but not always. Some pumps have limited automation options. Other pumps have no external control options, and it is best to steer clear of these when you have a pool heater of any kind.
Without further adieu, here is our round-up of popular variable speed pumps found in the Florida marketplace and our opinions on each with relation to solar pool heating systems.
Pentair Variable Speed Pumps
Pentair has the most popular variable pumps in the industry, and this is no different in Southwest Florida. We see this pump brand most often on new pools, especially by large pool builders doing new home construction pool installations. They provide great flexibility and good control options across the product line.
Pentair INTELLIFLO® 2 VST 011055
If you want the quick answer without reading further, our choice for variable speed pumps if the Pentair IntelliFlo 2 VST. This is the next generation IntelliFlo VS pump that incorporates a display that can be rotated or mounted remotely. This was definitely implemented to compete with the Hayward EcoStar pump that has this feature and the Jandy JEP-R remote display and control pad.
The reason we choose this pump over others is the combination of features, flexibility, and external control capability. Out of the box this pump has the best on-pump controls with the most intuitive menu. It allows you to program up to 4 speed buttons and 8 scheduled speeds to run at times of your choosing. There are also four program speeds that can be controlled by external automation systems. Pentair automation systems like the EasyTouch and IntelliTouch have full control over pumps speeds, but the more cost effective solar controllers, the SunTouch and SolarTouch, also have excellent control capability. For most systems we recommend the SolarTouch, which is a basic solar controller that will boost the pump speed during solar operation without taking over the on-pump controls, keeping the functionality of the on board buttons. For whatever reason, Pentair does not list the SolarTouch as a compatible automation system for this pump, but it most certainly is. We have sold hundreds of these combinations.
If you have another brand of automation the IntelliFlo can probably be integrated with it. If you have a Jandy Aqualink system with newer firmware, it can control the IntelliFlo out of the box (with the proprietary cable that comes with the pump). If you have another automation system with available relays, you can control IntelliFlo pump speeds with the Pentair IntelliComm II interface module, which converts analog inputs to digital signals the pump can understand.
One gripe we have with the IntelliFlo line of pumps is that when controlled exclusively by automation using digital controls, the display becomes inactive and you cannot see the pump RPM and power use on the pump display. You need to use the controller menu, which is more cumbersome. This does not apply to the SolarTouch control or controls that use the IntelliComm II.
The IntelliFlo is a 3 horsepower max pump with 2 inch inlet and outlet. You might wonder why you need such a powerful pump if you current pump is much smaller and if you have only 1-1/2″ plumbing. The answer is simple — it doesn’t cost much more to get the much more flexible 3 HP model, and you can run it at much lower speeds resulting in much quieter operation! The IntelliFlo is the most popular variable speed pump in operation today, and it’s pretty clear why.
Pentair INTELLIPRO® 2 VST 013001
This is the exact same motor and variable speed drive electronics as the IntelliFlo with a different pump design. It is a drop in replacement for Sta-Rite pumps and is black in color. All of the same automation options and features exist.
Pentair INTELLIFLO® VS+SVRS 011017
The IntelliFlo VS+SVRS incorporates a safety vacuum release system that complies with the Virginia Graeme Baker Safety Act. It is essentially the same pump and the IntelliFlo previous generation that did not have the removable display. We would expect Pentair to update this pump to incorporate the new display soon.
Safety vacuum release systems are problematic with solar pool heater and some pool features. Valves turning, purging air, and other system changes can cause nuisance tripping of the SVRS system, so they are not recommended for use with solar pool heaters unless required by law. An external SVRS system is preferable to one integrated with the pump in this case.
The IntelliFlo VS+SVRS pump has the same proprietary cable as the regular IntelliFlo, and all of the same external control options.
Pentair SUPERFLO® VS 342000
The SuperFlo VS pump is a 1.5 HP model with 1-1/2 inch inlet and outlet. It seems at first glance to be a great lower cost option for older pools with smaller plumbing and pumps, or newer efficiently built pools. However, the lower horsepower means that you have to run it at a higher speed to achieve the same flow rate, which means there is more noise. The small amount of initial savings and ongoing operational savings is not worth it in our opinion.
One area it does shine is that it can run on 120V or 240V power, so if your existing pump is not wired for 240V, this is an excellent option if you want to upgrade to a variable speed pump. This is exceedingly rare in Southwest Florida, so we do not run into this issue very much.
External controls on the SuperFlo are pretty flexible. The control is analog, which requires a separate relay or switch for each speed you want to run with external automation. Connecting the pump to a SolarTouch will allow it to run at a higher speed during solar operation, but you need additional relays or switches to get additional speeds. The on board controls are far less capable than the IntelloFlo pump line, but for basic pool setups it can work.
We do not recommend or install this pump, but if your pool builder or pool service company installed it, we can make it work with minimal work.
Pentair SUPERMAX® VS 343000
The SuperMax VS has the same motor and electronics as the SuperFlo VS, and is intended as a direct drop in replacement for the Hayward® SuperPump® single speed pump. It has all of the same external control capability as the SuperFlo VS.
Pentair INTELLIFLOXF® 022055
The IntelliFlo XF pump uses the same motor and electronics as the IntelloFlo pump (although they have not upgraded the display to the remote mount option yet). It is intended as a small commercial pool pump with 2-1/2 inch or 3 inch pump inlet and outlets. It also has an easy carry handle (which we don’t really understand, because you shouldn’t really have to move the pump after installation).
The most important feature listed for the IntelliFlo XF pump is the improved hydraulics from redesigned interior passageways and parts. This results in smoother, more efficient operation according to the manufacturer.
The IntelliFlo XF has all of the same external control options as the IntelliFlo VS pump. We recommend this pump for pools with larger solar pool heating system or commercial pools. It’s just slightly more expensive, so it’s a good option for those with higher flow rate needs.
Pentair INTELLIPROXF® 023055
The IntelliPro XF is the same as the IntelliFlo XF, but black in color and branded as a Sta-Rite pump.
Hayward Variable Speed Pumps
Hayward has very loyal dealers and pool builders, and we see lots of new pools being installed with all Hayward equipment, including automation, chlorination, filters, and pumps. The external control options range from good to non-existent.
The EcoStar is Hayward’s flagship variable speed pump, and it has been on the market for a long time as a strong competitor to the IntelliFlo from Pentair. This 2.5 Max HP pump has excellent flexibility in terms of performance, and low run speeds for most functions results in quiet operation. It has a rotatable display that can also be mounted remotely on a wall.
The pump interface allows direct on board programming of times and speeds as needed for just about any pool schedule. It can connect via regular wire (non-proprietary) to any Hayward automation product for seamless automation using the controller menus. There are three analog inputs that allow control of speeds using non-Hayward automation using relays. Unfortunately, when using external controls from non-Hayward automation, it’s an all-or-nothing affair. You need to control all speeds and schedules externally, which means that you often need to use a traditional mechanical timer for on-off operation if using a basic solar controller like the Hayward GL-235 or Pentair SolarTouch. The non-Hayward automation is a little confusing to set up, but the pump does allow external control of up to 8 speeds by combining the three external inputs, but that’s typically overkill, with 3-4 speeds the most needed for the vast majority of pools.
The nice thing about the non-proprietary cable and control is that just about any automation system with available relays can control the pump speeds without an intermediary interface.
We recommend this pump when converting to variable speed and there is existing Hayward pool automation. The price tends to be slightly higher than Pentair, especially for the solar automation options with the exception of the basic Hayward GL-235 controller. While it’s not our first choice, it can work well in many situations and has adequate power for just about any residential pool with solar power.
Hayward TriStar® VS
The TriStar pump is very similar to the EcoStar, but intended for lower horsepower needs. Rated at 1.85 HP, this pump can replace smaller pumps, but we do not recommend it with solar pool heaters for the same reasons we don’t recommend the Pentair SuperFlo (noise, savings).
While the external control options with non-Hayward relay-based control are the same as the EcoStar, the TriStar has a frustrating nuance that we need to watch for when integrating with Hayward automation. You can only use the TriStar with the RS-485 Hayward Automation option if the controller has certain firmware versions. If not, a board replacement is required, or the pump will need to be controlled using relays.
Hayward Max-Flo VS SP2302VSP
It is frustrating to find a Max-Flo VS pump installed at a home when the owner wants solar pool heating. There is absolutely no external control capability. That means you cannot increase the speed of the pump during solar operation. The best we can do is attempt to run the pump at a higher speed via a schedule during the typical time of day when solar pool heating would be active. This does not provide a good balance of performance and energy savings, but at least the pump is inherently more efficient than a single speed pump, and we can run it at a slower speed outside of the “solar window.”
The earlier versions of this pump didn’t have a time schedule, just a run time for multiple speeds. The V2 version of this pump added a real time clock, but the interface is seriously lacking.
This 1.5 HP pump has 1-1/2″ and 2″ inlets and outlets and has 120V and 240V versions.
We cannot recommend this pump to anyone that wants to heat their pool using any technology.
Hayward Max-Flo VS SP2303VSP and SP23115VSP
This is essentially the same pump and motor as the SP2302VSP, but with a rotatable display that has the automation and programming features of the EcoStar pump. For that reason, we can recommend it where the EcoStar is recommended, but for very small pools where the pump horsepower requirements are very low. However, lower horsepower means higher run speed and more noise.
Jandy Variable Speed Pumps
One of the most respected brands in the industry, with fiercely brand loyal pool builders, is also the most expensive option usually. There are thousands of Jandy Aqualink automation systems installed in Southwest Florida, and integrating with the same brand pump is often the easiest choice, especially for older automation systems.
Jandy VS PLUSHP
The newest variable speed pump from Jandy is also their most powerful and flexible option. Rated at 2.7 HP, it falls right between the Pentair and Hayward flagships, and is more than enough power for most residential pool applications. The pump comes with a capable on-board controller that controls only two timed speeds for some reason (8 speeds total). This is far less capable than other major brands. Nonetheless, the controller is capable enough and easy to program. The pump, like the IntelliFlo XF from Pentair has a mostly useless carrying handle but it’s a feature appreciated by the initial installer.
There is one very unique feature with this pump. You can order it without an on board controller if connecting it to a compatible Jandy automation system. This does cut down the cost, and reduces some of the complexity in the system.
We don’t have enough experience with this pump to recommend it or not, and it is not popular in Southwest Florida at this time.
Jandy VS FLOPRO™
The FloPro line comes in both a 1.5 HP and 2.0 HP model. The manufacturer lists its compact size as a feature. It uses the JEP-R controller, which can be mounted on the pump or on the wall. You need this controller whether integrating the FloPro with Jandy automation systems or with other automation systems. It uses relay control to change speeds on the pump. The pump can be used to control the time schedule, or schedules and speeds can be taken over completely by external automation.
When taking over speeds and schedules completely in external control mode, everything is pretty straightforward and speeds for each pool function can be easily programmed and delivered using standard (non-proprietary) control wire. The JEP-R controller has a serious flaw, however, when used to control speeds externally with a basic solar controller that just overrides the pump’s internal schedule. If the solar controller turns solar off (if the desired temperature is met or solar energy is not available), the pump fails to go back to it’s regularly scheduled speed. This can cause serious issues be not providing adequate circulation, and also turns off flow for features like waterfalls and spillovers.
For this reason we cannot recommend this pump with solar pool heating unless there is an existing compatible Jandy controller on site. When this pump is already installed, we can trick it to keep running using a mechanical timer and a solar controller, but that adds to the cost and complexity.
The ePump comes in 1.0 HP and 2.0 HP models. We definitely do not recommend the 1.0 model for solar pool heating system, even on very small pools, because of the high pump speed usually required that results in higher noise levels, negating one of the major reasons for buying a variable speed pump. The 2.0 HP model will work fine, but the cost-benefit ratio is not up there with major competitors in our opinion.
The ePump comes without a controller, and it can be controlled with any of the Aqualink brand controllers or the JEP-R standalone controller. The JEP-R is required for operation with non-Jandy control systems, and has the same features and limitations as the FloPro line.
Other Variable Speed Pumps
Waterways Econo Flo VS
The Waterways brand is sold by discount pool stores and via pool service companies typically. Their variable speed pumps come in 1.65 HP and 2.70 HP models. Most of these pumps out there have absolutely no external control capability, so they are not suitable for pools with solar pool heating (or any heating for that matter). There is a newer version with external control, which appears to be adequate for typical automation needs, but it is minimally documented and we have not run across any of these pumps locally. Although it will probably save on energy costs, we do not recommend this economy brand pump. It is not popular with pool builders and service companies. We say stick with the big names in pool equipment for the best experience.
This manufacturer/brand is out of business from what we can tell, and with respect to solar pool heating systems, that is good news. These pumps did not have the external control capability needed and had a frustratingly inflexible schedule and speed control logic. There are some out there in Southwest Florida, and we require that they be replaced when installing a solar pool heater.
Other Brands and Manufacturers
If the pump is not listed above, you would be best off steering clear. We recommend you buy one of the proven brands and models, which are easily serviced by thousands of pool professionals and well documented and supported for solar pool heating and automation system owners.
Choosing The Best Variable Speed Pump for Solar Pool Heating Systems
After comparing all of the available options, we recommend the Pentair IntelliFlo 2 VST hands down over the competition except in situations where competing automation systems are already installed. The IntelloFlo line offers easy connection with the entire Pentair automation line including the Pentair SolarTouch controller, our favorite basic solar controller for basic pool systems.
The IntelliFlo is not the cheapest option, but for just a small amount more you can get the best, maximizing your noise reduction and providing unparalleled flexibility. If you choose another variable speed pump due to cost, make sure it will provide the needed external controls to support a pool heater, and it will provide an adequate range of flow rates to support all of your pool features.
If you are unsure which variable speed pump to choose based on our comparison, contact us and we will help you make an informed decision based on your needs and budget.
Here is Pentair’s promotional video on our top pick, the IntelliFlo 2 VST: