Change single speed pump to 2 speed to save electricity?

[heatmisr]

So, I am trying to decide whether or not to pull the trigger and replace my working single speed pump with a 2 speed to save some money on my electric bill.

I currently have a 1HP single speed Waterway pump with an AO Smith motor. I usually run it for 12hrs/day, 2 cycles of 6hrs, but this year I cut back to 10hrs. I haven't been able to figure out my flow rate, so I have no clue how long a turn over takes. Maybe you can help me figure that out too... :-D. My electric rate is approximately $0.185/kwh.

Using Jason's basic calculation of 1HP = 1kwh, I get the following:

1kwh x 10hrs = 10kwh/day to run pump
10kwh x 30 days = 300kwh/month
300kwh x $0.185 = $55.50/month to run the pump

I'm looking to replace it with a Hayward Power-Flo Matrix 1HP dual speed. I can't find the stats on it for high or low, so I can't calculate how much it will cost to run. I guess if low uses 1/4HP and I use the same assumptions and calculation, it would cost me $33.33/month to run 24hrs. That is a savings of $22.20/month. That's if I am calculating this right and the 1:1 assumption is the same.

I have found the pump online for $258 and $299. Since I run the pump 5-6 months/yr, it would take about 2 1/2 seasons for me to break even, assuming my rates stay the same.

Another thing for me to consider is the Liquidator. I did the 3/8" conversion and it increased my flow, but I still have to close the valve from the skimmer slightly to get a flow of about 2.5. I do that instead of opening the flow valve all the way because I don't want to run the chance of the pump kicking on and getting too high of a flow. Would running the pump on low work with the liquidator?

What do you think? Are my calculations correct and if so, should I make the change?

 

[JasonLion]

Your calculations all look close enough. I get a slightly higher monthly savings based on a 20 hour run time, but that isn't a significant difference.

However, it is unlikely that the Liquidator will work at all well on low speed. The pressure differential that it depends on will be far lower on low speed.

 

[Crzyfrlss1]

You can save a little money by getting the same pump I have, it is identical to the hayward you mention in every way. Even the pump basket fits on one or the other.

I think I found mine for around $259

I know I definitely save $$$ by running on low all the time and only using high speed when cleaning and vacuuming.

 

[heatmisr]

Is that pump a side discharge or vertical?

 

[Crzyfrlss1]

Is that pump a side discharge or vertical?

It can be both.

Just remove the switch cover, then the 4 motor through bolts and turn the discharge where you want it and but back it together.

Takes maybe 10 mins. tops.

 

[heatmisr]

Thanks for your input. Still mulling it over. I think the electric savings make it worth it, but I still have some thinking to do about the liquidator part of it.

 

[rv4hess]

I don't believe you would need to run your pump for 24 hours a day, one water turnover per day should be good. You ought to be able to save more on your electric bill. It will not require double the run time of a 1 hp because the turnover ratio is more efficient.

Since your pump is still working I would say it could be worth $75-100 on Craigslist or eBay.

Will you have installation expenses or can you do it yourself?
Do you have an auto cleaner or vacuum manually? You will probably use the high speed for either.

I don't know anything about liquidators.

I know I'm very happy with our 2 speed pump. It was a much easier decision for us because it was only a $50 upgrade during new purchase.

Best of luck,
John

 

[heatmisr]

Well, I took the plunge and bought the Hayward 1hp-2speed. The pump is great, but now I have other problems....LOL.

It has become apparent that I am going to have to hard plumb my system or come up with some compromise in between. Everything is great on low speed, but high is a different story. On the pressure side, I have flex hose off the return, to a 12" piece of PVC (for the liquidator connection), to a piece of braided PVC, to the filter. Well after running on high about 20 minutes, the connector between the PVC and flex hose blew off. Luckily I was right there and caught it before half the pool emptied. So I tightened all the connectors, problem solved.

Then I see water shooting up in the air from the return. Lo and behold, the poolskim connector has been loosened from the ridiculous return pressure and it is now pointing skyward. So, I get a wrench and tighten the bejesus out of it.

Then about 30 minutes later, I hear this awful sound coming from my brand new pump. On the suction side, I have flex hose, to PVC (again for the liquidator), to braided PVC, to the pump. I run over to see what is happening and realize that now the pump is collapsing the braided PVC. So, I need to change that.

I love this pump because it is quiet and definitely efficient, but this is a definite case of biting off more than you can chew....LOL.

For anyone that may be interested, the Liquidator works fine on low speed. I get the same flow on low speed with the new pump, skimmer valve fully open, that I was getting on the old pump with the skimmer valve slightly closed. I acutally had to turn down the liquidator from 2 to 1 because the increased run time was overchlorinating the pool.

Here's a pic, with the old pump, so you can see my setup:

Any suggestions?

 

[Sportsman]

those must be your before photos because that's not the Hayward Power Flo Matrix. I made the switch from 1.5hp single speed to the 1 hp dual speed and I'm glad I did.

From the photo, you have flexibility in where your pump/filter is. Just hard plumb it with 1.5" PVC. If necessary you can use a small section of flex PVC. A lot on here don't like it but if you're not burying it, you should be fine. It will beat the heck out of the flex hose you have. It is expensive so I would use schedule 40 PVC as much as possible.

 

[heatmisr]

Yes, it is the old pump. I took this photo a year or 2 ago because I have also done the 3/8" upgrade for the liquidator and this pic shows the original set up.

I ended up buying a 3' section of the hose, because I was having trouble finding the flex PVC locally. I saw some flex PVC online, but it was going to cost $18-$20 to ship it. I was kind of taken aback by that since that is the same cost as the amount of PVC I need. I really don't want to hard plumb it. I'm resourceful, so I could do it, but I just don't want to go through the process. Heck, I can't even bolt the pump to the base. The Hayward connector is bigger than the original Waterway connector, so the holes don't line up. I'm thinking about doing the flex PVC with glued-on regular sch 40 connectors. More stability, but I can still grab the entire set up and store it in the shed for the winter.