How Does a Variable Speed Pump Work?

What is a Pool Pump?

All swimming pools, great and small, require a pool pump.  Even spas and above ground pools require a swimming pool pump.  The reason is that the water needs to be circulated a certain amount of time each day.  Water is drawn from your swimming pool from the skimmer, main drain, or a combination of the two.  It is then pushed through your equipment plumbing system.  It goes through optional accessories such as a salt cell, in-line tablet feeder and a heater.  The other required piece of equipment for any pool besides a pool pump is a pool filter.  

When water is passed through the filter, it allows dirt and debris to be captured.  Circulating your water also mixes your chemicals, allowing them to work.  Proper circulation is key to any clear, clean, and most importantly, safe swimming pool.

Swimming pool pumps consist of two parts:  the wet end and the dry end.  The dry end is the pool motor because no water ever should touch this portion.  The other part is called the pump housing or volute.  This is where the water passes through.  This is where your pump basket is. The motor is protected from water by a two-part ceramic seal located in between the two parts.  If your pump is dripping from the middle, you probably have a failing seal.  I suggest fixing it right away so as not to damage your pool pump.

Single Speed Pumps

Single speed pumps have a single speed motor that does just that: run on a single speed.  This speed is measured in what is known as Revolutions Per Minute (RPMs).  A single speed pump is always on a “high” setting of 3,450 RPMs.  This utilizes a ton of energy.  Did you know that after your air conditioner, your single speed pool pump is the most expensive thing to run?  The reason is they are not efficient.  They not only pull a lot of energy, but lose a lot of energy.  Have you ever touched your pool motor when it had been running? Hot, huh?  These pumps are considered “old technology” and even outlawed by the Department of Energy in a lot of States.

If the DOE is taking notice, that should be a red flag as to how much of an energy-guzzler single speed pump that uses only windings.

Variable Speed Pumps

I am sure you have been hearing the hype about these for several years now.  The reason being is they are the new technology when it comes to pool pumps.  Unlike single speed pumps, variable speed pumps can be programed to run at…you guessed it!  Varying speeds.  A variable speed pump still has a wet and a dry end.  One major difference is that the dry end has the pump timer on it.  No more intermatic wall timer with just an on/off switch.  That is ancient history.  With a variable speed pump (VSP) it is programmed at the pump.  They will be set to run at much lower RPMs, switching between them throughout the cycle.  Since our pool size has not changed, we still need to move the same amount of water through our filters.  Since we are doing it at a lower speed, we just run it longer.  Believe it or not this is much less expensive than your single speed pump.  Here is why.

A variable speed pump, in addition to windings, uses what is known as a permanent magnet motor.  This type of motor is in magnetic resonance imaging..which I am sure you have heard of.  MRI’s?  It is also a totally enclosed, fan cooled motor so you are not losing that excess heat you once were with your single speed pump.

You may be wondering about your water features and spa jets.  How will they operate at a lower speed?  That is the beauty of a variable speed pool pump.  You can still run it at 3,450 RPMs as the time calls for.  Even at this speed, because of the design, it will still utilize less energy.  

Variable speed pumps pay for themselves.  How quickly can depend on how much you paid for the pump.  The average homeowner will save approximately $70 per month on their power bill.  Such a noticeable difference has been noted by most major utility companies.  They may be offering you a rebate if you switch.  It must be an Energy Star Rated pump, however.

Are Variable Speed Pumps Expensive to Purchase?

The answer is, they can be.  It all depends on where and how you shop.  Your local swimming pool supply store will charge a couple grand for a name brand VSP.  Even your pool guy is probably paying close to $1,500, even with his discount.  The amazing news is that you don’t have to pay a fortune for a quality, name brand pump.  The American-made, household name of Black & Decker has lended their expertise to the swimming pool industry.  Yup, they make several variable speed pool pumps for both in-ground and even above-ground swimming pools.  As Energy Star rated pumps with a five year warranty, you can save AND have peace of mind.  Check one out hereSee you poolside!