Downgrade from 2.5 HP pump

[tavacska]

After my last post, I have checked more details of my pump system. I found out the 2.5 HP is way higher than what I need.

My system:
1. Pool size: 20k Gallon, 2 bottom drain, 2 skimmer, 1 cleaner
2. Spa: 5 nozzles
3. SWG: Hayward T15
4. Filter: Pentair DE 60
5. Heater: one heater
6. Automation: Zodiac RS8
7. Pump #1: Jandy JHPU 2.5HP single speed, for pool/spa
8. Pump #2: Jandy JHPU 2.5HP single speed, for water fall
9. Pump #3: Polaris 460 for cleaner
10. Pump #4: little standing one for Spa booster
11. Distance to return: 75 ft

Based on some calculation, it seems 40 ft head/60 gpm is good enough for the Spa need. So 1.5hp/1.65hp should be good enough for me. I am looking for some motors dual speed or variable speed to be installed on the wet part of the pump. V-green 1.65 Hp is one of the options.

Any comments?

 

[needsajet]

I wouldn't worry too much about the pumps that don't run a lot (e.g. spa jets and waterfall). You may need the high HP to get the massage action you want and the flow for the waterfall. You'll save the most money by having a right-sized circulation/filtration pump. For me and for your pool (two skimmers), that would be a 3 HP variable speed, so I have lots of power for quick skimming when needed, but can dial it down for normal filtration and circulation (the long hours of pump time). That said, the 1.5 HP will be enough, so I would give that a go if trying to save some coin.

 

[tavacska]

What is that standing pump for SPA? It is configured as AUX#1. When it is turned on, the jet spurs out very harsh. Is that booster good enough to compensate some loss of HP?

 

[Savo]

Hello tavaska,
I have a new-in-box, 2.5HP, 2-speed pump that I was going to list for sale in the 'coffee bar' forum - hoping to avoid the hassle of listing on eBay. I purchased this last winter to replace my single-speed, but the rework of my automation system is going to be too much. Hayward SP3220x252. 2.5HP, 2-speed TriStar pump. I realize your thread is about lowering the HP to save $$, so I'll suggest that I would cut you a great price to save me the trouble. ( bought via INYO pools, but kept it way beyond the return period). - Thanks, Savo

 

[mas985]

After my last post, I have checked more details of my pump system. I found out the 2.5 HP is way higher than what I need.

My system:
1. Pool size: 20k Gallon, 2 bottom drain, 2 skimmer, 1 cleaner
2. Spa: 5 nozzles
3. SWG: Hayward T15
4. Filter: Pentair DE 60
5. Heater: one heater
6. Automation: Zodiac RS8
7. Pump #1: Jandy JHPU 2.5HP single speed, for pool/spa
8. Pump #2: Jandy JHPU 2.5HP single speed, for water fall
9. Pump #3: Polaris 460 for cleaner
10. Pump #4: little standing one for Spa booster
11. Distance to return: 75 ft

Based on some calculation, it seems 40 ft head/60 gpm is good enough for the Spa need. So 1.5hp/1.65hp should be good enough for me. I am looking for some motors dual speed or variable speed to be installed on the wet part of the pump. V-green 1.65 Hp is one of the options.

Any comments?

Exactly how did you do the head calculation? Also, how do you know 60 GPM is enough for the spa jets? Are the jets currently too strong?

Assuming your calculations are correct, you would need to downsize the pump impeller to use the V-Green motor. You can't put a lower HP motor on a higher HP impeller.

Another option would be to swap the current motor with a two speed. That way you will get the same jet performance on high speed while being able to run on low speed for the pool.

 

[tavacska]

Exactly how did you do the head calculation? Also, how do you know 60 GPM is enough for the spa jets? Are the jets currently too strong?
Assuming your calculations are correct, you would need to downsize the pump impeller to use the V-Green motor. You can't put a lower HP motor on a higher HP impeller.
Another option would be to swap the current motor with a two speed. That way you will get the same jet performance on high speed while being able to run on low speed for the pool.

I did the head calculation using Pentair website. Link: Pump Calculator
I am using 60 gpm as flow rate. This is coming from 5 nozzles * 12 gpm/nozzle = 60 gpm (spa). Pool flow rate will be small as 41.7 gpm for 8 hrs turn.
My current jet is ok, with pretty much pressure with 2.5 HP pump only. With the help of booster, it will have much more pressure and a little annoying.

 

[mas985]

The Pentair site leaves out a lot of components that add head loss. Filters, heater, skimmers, main drains, spa jets, valves, all add head loss. So your number is likely to be much too low unless you added those components separately.

What inputs did you use for the calculator?

What is the distance between the pump and spa?

What is the filter pressure when in spa mode?

By booster do you mean the blower?

If your current jet strength is ok, then why do you want to downsize the pump? This will make the jets much weaker.