pump question

[jrtvols]

What is the difference between an inground pump versus an above ground pump? thanks in advance..

[Watermom]

I'm definitely not the expert on pumps. But, this summer when my pump on my above ground pool died, I let our resident expert on pumps - my cohort moderator Al (Poconos) pick out what I should get as a replacement and he chose an inground pump and it worked well.

[jrtvols]

Thanks for the reply.. I have an 18x36 inground pool and my pump locked up last night. what little research i have done regarding prices, it just seems that the above ground pumps are a little cheaper. I want to be sure and install the right kind of pump.

[mas985]

I believe there are two factors which separate an above ground from an inground pump.

1. NPSH (net positive suction head) is much lower on an above ground pump since they do not have to prime a pump that is above the pools's water line like many inground pumps.
2. Above ground pumps tend to be lower head pumps since they are usually very close to the pool and do not experience as much head loss as an inground pool.

So the result is that above ground pumps do not need to be as robust and are cheaper than inground pumps.

So while you can use an inground pump for an above ground pool, it is usually overkill.

[jrtvols]

thanks for the info mas985..

[waste]

I saw this yesterday when it was new, but don't know enough about the various pumps to have responded. The only thing I'd like to add is that Hayward Superpumps have some verbage in the lit. to the effect that "these should only be used with 'permenent pools' (ie. ones that don't get taken down, though I think the caution is also about AG pools).
As I said, I don't fully know, perhaps one of our 'pump experts' will expand on why they can't be used.

[mas985]

I saw this yesterday when it was new, but don't know enough about the various pumps to have responded. The only thing I'd like to add is that Hayward Superpumps have some verbage in the lit. to the effect that "these should only be used with 'permenent pools' (ie. ones that don't get taken down, though I think the caution is also about AG pools).
As I said, I don't fully know, perhaps one of our 'pump experts' will expand on why they can't be used.

One of the reasons is because of low head. Using a high head pump on a low head loss pool will result in the pump not having enough load on the impeller. Not only is this inefficient in terms of energy usage but it can also burn up the pump. For most pool pumps, they will draw the most power with the lowest resistence which is like operating on the right most side of the head curve.

When picking out a pump for any pool, you want to make sure you are operating in the middle of the head curve where efficiency is the greatest. For high head pools (IG), this is between 45-65 feet of head. For low head pools (AG), this is usually below 40 feet of head.

Here is a good reference for the difference:

http://www.poolplaza.com/inground-aboveground.shtml

[CarlD]

If you go with an I/G pump, remember that you will probably need a lower HP rating--they are usually full-rated, rather than uprated.

I have 20,000 gal (approx) in an AG pool, but I have solar panels as well. I only have a 1hp Hayward Superpump and a 200lb sand filter. It's a two-speed and I LOVE it. I run it on low-speed 99% of the time.

I DEFINITELY recommend 2 speed pumps. Plus, sand filters run better when they are running below capacity, well below capacity.

Mine is simple--there's a speed switch on the back of the motor--I don't even bother with remote speed switching.

[huskyrider]

mark,

Thanks for the awesome replies.

When picking a pump motor I always look at my TDH (total dynamic head) first and then factor in my elevation difference between the pool equipment and the water level when factoring my PSH.

The bottom line is really simple, above ground pool pumps are for just that and inground pumps are for their applications. Don't switch between the two for the opposite application.

See ya,
Kelly