If you are building a new pool or simply replacing a worn out pump, you have to decide whether to go with a standard single speed pump, or spend the extra money and get a high efficiency variable speed pool pump. Now a standard 2.0 HP pool pump costs about $900 installed, and a high efficiency variable speed pool pump costs about $1600 installed, so the cost difference is significant, but so are the savings.
There are really three parts to this discussion:
There are at least five different ways in which a variable speed pump can save you money. You may not have thought of some of these things, but when you add them all up, they amount to a pump that pays for itself about five times over a ten year lifespan.
A standard pool motor operates at 40 – 70% efficiency (generally closer to the 40% mark) while a variable speed pump motor has an efficiency rating of over 90%. Sometimes your standard pool motor gets so hot you cannot even touch it. This is because the energy is being converted to heat instead of actually pumping water.
A high efficiency motor stays cool to the touch, no matter how hard you run it. This is because almost all of the energy consumed is being converted to motion (i.e. pumping water)
The variable speed motor is so much more efficient because it uses a permanent magnet motor – the same technology used in today’s ultra-efficient hybrid cars.
The variable speed pump combines this permanent magnet motor with a variable frequency drive (VFD). Variable frequency drives have been used in industry for decades, but only recently have been adopted in the swimming pool industry.
The net result is that the overall efficiency of the motor alone saves you 40 – 50% in your electrical costs if you keep your flow rate the same as it is now . . . but part of the savings equation is the fact that you can dial the flow rate down as needed to save a lot more money. Read on . . .
The fact that you can adjust the flow rate of this variable speed pump offers even more potential for savings. Let’s say that you have a pool/spa combination with a 2.0 horsepower pump that has a flow rate of approximately 120 gallons per minute. Now you need that flow to make the spa jets work properly, but when you want to just circulate the pool, you might need only 50 – 60 gallons per minute.
With a standard single speed pump, you are forced to run your pool at this high speed 365 days per year, even though you are not using the spa that often.
With a variable speed pool pump you can dial in the exact flow that you need at any particular time. Let’s assume that you have a 24,000 gallon pool with an attached pool spa combination. Here are your varied flow requirements. When your spa is running, you want lots of flow to make the jets really powerful but when the pool is simply filtering, a much lower flow rate is better. When you turn the pool cleaner on, you want a little higher flow to make sure that the skimmers and main drain suck in all the debris that the pool cleaner stirs up.
|Function||Speed||Flow||Power Usage||Energy Cost|
|Spa||3000 RPM||~120 GPM||1600 Watts||16 cents/hour|
|Pool Circulation||1600 RPM||50 GPM||300 Watts||3.0 cents/hour|
|Pool Cleaning||2000 RPM||~75 GPM||450 Watts||4.5 cents/hour|
Now compare that with the cost of running a standard 2.0 HP pool pump:
|All Functions||3450 RPM||~120 GPM||2880 Watts||28.8 cents/hour|
As you can tell, your cost savings are very significant. When you drop your energy consumption from 2880 watts to 300-400 watts per hour, the cost savings add up pretty quickly. So . . . how much can you save? We will discuss that in depth in the next section.
Reduced chance of priming damage – when a pump loses prime, it super heats the water inside the pump pot and damages the pump basket, seal, impeller and other components. By running the pump at a much lower speed most of the time, the chance for priming damage is greatly decreased.
Longer lasting motor – standard pool motors last 3 years on average, five years at the most. This means that every 3-5 years you are going to spend $550 on a pool motor (including labor, seal, gaskets and taxes). Variable speed motors generally last ten years or more, because they are built differently and run so much cooler.
This means that over a ten year period, you will spend over $1000 on replacement motors on your standard pump, but will generally have no motor replacement costs on the variable speed pump.
So what happens if your DE filter pressure gets too high and you are not there to backwash it? You know the answer. The pump keeps pushing and pushing at the filter grids and manifold until something gives way. The result is often expensive filter grids and manifolds.
One of the added benefits of the variable speed pump is that it puts much less pressure and wear and tear on your filter grids or filter cartridges. It greatly reduces your chance of broken grids.
Did you know that your filter is more efficient at lower flow rates? Yep, its true. Your filter media does a more effective job of filtering out small particulate at lower flow rates.
These are just some of the tangible savings that you get from having a high efficiency variable speed pump on your pool. Not to mention that your pump will be much much quieter. At lower speeds you can barely hear it!
So how much can you actually save? That is the subject of the next section.
Jandy variable speed pumps have the exclusive feature of being able to also control your poolsweep pump operation to a limited degree. This really works best on “pool only ” arrangements without a lot of water features. See below for more information.
How is this possible?
The Jandy VS Flo Pro 2.0 model features a unique “auxiliary load operation” feature. We these contacts to a relay so that when the pool pump reaches at least 1725 RPM, then the pool-sweep pump comes on after a three minute delay.
Here is how you can use this to control the poolsweep pump:
How does this save me money?
This keeps you from having to purchase and maintain a separate dual timeclock/freezeguard. It also ensures that the poolsweep pump will not come on if the main pump is not on.This feature is best for simple pool only situations and not for pool/spa combinations.
First, if you have a pool/spa combo, you are going to really want/need full control system – the Jandy AquaLink system is great for this and integrates perfectly with our variable speed high efficiency pumps.