Current pump about to fail, proactive replacement

[Dubyahjay]

Converted to SWG at the beginning of the season and it was the best decision I've made yet!

Even after a full seal replacement and service on the existing, 8 year old Hayward Superpump, there was a slight leak that could not be controlled. I knew that the pump probably wouldn't make it through the season. Since I inherited the pool, I've had to learn almost everything the hard way. Which has been awesome! (No really)

I need a confirmation on my numbers for the replacement pump please.

32K gallons
4000 GPH or 66.67 GPM turnover
Feet of head average from the main drain and two returns is 43.45

The Hayward chart tells me that I should purchase the 1.5 HP pump. My concern is that I am running 1.5" pipe and will run into excessive pressure.

Current filter, which was deep cleaned at the beginning of the season is a Hayward S244t. This filter supports 45 GPM with 1.5" pipe.

Will I be safe with the 1 HP pump? I think the 1.5 HP is overkill.

The current 3/4 doesn't seem to turn over the pool effectively. Also, I have to close the main drain and one of the returns to get acceptable manual vacuum pressure.

Thanks for the input ya'll!

 

[jblizzle]

How did you calculate the head loss? Not that it even matters
Also there is no point in looking at turnover: See http://www.troublefreepool.com/content/152-determine-pump-run-time
There is also no such thing as "excessive pressure"

Generally you want the smallest pump that gives you enough flow to meet your equipment needs and filtration is actually better at lower flow rates. It does not look like you have any high flow needs.

Is your current motor 115V or 230V? I would suggest a 1HP 2-speed pump like the Superflo (or SuperPump) assuming you have 230V power available.

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Also not uncommon to have to close the floor in order to vacuum ... the water takes the path of least resistance. But, closing a return would actually lower the total flow rate, so that does not make any sense, unless I misunderstand.

 

[bobodaclown]

X2 on the 1HP 2-speed. I've added a 2-speed and run on low 95% of the time. I only run on high to check the filter pressure and initial prime after cleaning, other wise it's on low. My pump runs 10 hours a day because I need the SWCG to produce enough chlorine.

 

[Dubyahjay]

Current run time is two 4 hour blocks, one starting at 8AM and another at 3PM. With my SWG set to 40%, FC levels are stable at 4 and have been for the majority of the season.

I did not calculate head loss correctly it seems. Using http://www.engineeringtoolbox.com/pvc-pipes-equivalent-length-fittings-d_801.html as a starting point, my 43 number would be a good bit lower.

I'll try with only the main drain closed on the next vacuum. Placebo effect maybe?

The current pump is wired 115V. Is there a two speed option at that voltage?

 

[jblizzle]

You would be limited to the Superflo 3/4HP 2-speed like this one: http://www.sunplay.com/Pentair-SuperFlo-Pump-341111-p/341111.htm
Or Hayward likely has something similar.

These would offer the same flow as your existing pump on high ... which should be sufficient.