So for Head, I measure the length of the return lines or both return and suction.? I have a 20 x 40 and the original pump which was a Hayward Super 2 (1 HP) went down. I am shopping for pump to replace it. It was a champ at pushing thru a Pentair FPS 48 D.E. I have been trying to figure up the calculations for head. My set up has 2 skimmers, 2 returns, 1 main drain, and the Pentair FPS 48 DE. All lines are 1.5 and there are no extra water features. My returns are roughly 6 inches below water line ,12 inches below coping , and 18 inches total lift to pump inlet. Pump is 20 feet from pool edge and sits off center left at about the 10 ft mark of the 40 foot length.
Measurement
- Thread starter Amtorcha
- Start date
hello Amtorcha.... I'm going to request a member whose particularly good with this stuff to peek in at your post.
Paging @mas985
Maddie
Paging @mas985 Maddie
- May 3, 2007
- 17,038
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Calculating head loss is a non trivial exercise. It is related to the length of pipe but also the type of fittings, filters, heaters, valves, eyeballs, etc. Not to mention that the pump's head curve also determines head loss or more accurately, the pump's operating point.
In most cases, it is unnecessary to calculate head loss. Especially when sizing a pump.
Because of recent DOE regulations, you will most likely be purchasing a VS pump and since they are variable, sizing is much less important.
www.troublefreepool.com
Right now price and availability is probably the most important factors.
In most cases, it is unnecessary to calculate head loss. Especially when sizing a pump.
Because of recent DOE regulations, you will most likely be purchasing a VS pump and since they are variable, sizing is much less important.
Pump DOE Regulations - Further Reading
www.troublefreepool.com
Right now price and availability is probably the most important factors.
Bill1974
Well-known member
It could be done, but it would be a challenge. Ideally you would need to know length of every section of pipe and the size and type of every fitting. Generally not something to be calculated by hand, but could be with the help of spread sheet (still not that easy). There are programs specifically meant for doing this, although I doubt they are every used when designing a residential pool unless it's something insane or some experiment to lower operating costs.
If everything worked well with you existing pump and you recall what the pressure readings were on your filter. You could compare the pump curves of other pumps to your current one at the pressure to see if it would flow more or less. But generally I would say another 1 hp pump would be fine. If your pump died, I would rebuild it. A replacement motor is easy to install, and at the same time replace all the seals in the pump for another $15. This way you will not have to do much if any replumbing and it should work just like it did before. A replacement motor is about half the cost of whole new pump. Usually you can find a replacement motor on Amazon. Watch a couple of youtube videos, it's pretty easy and just make sure you set the motor to run at the correct voltage (otherwise it will let out the smoke in short order).
For comparison I have a 20 x 40 pool w/ 2 skimmers and 2 returns, sand filter and use a 1-1/2 HP Hayward super pump. If you step up to a larger pump you may be able to reduce you running time. If you go to variable speed the operating cost should go down too. If you consider changing to a different pump, make sure your electric service for your pool pump can accommodate it.
If everything worked well with you existing pump and you recall what the pressure readings were on your filter. You could compare the pump curves of other pumps to your current one at the pressure to see if it would flow more or less. But generally I would say another 1 hp pump would be fine. If your pump died, I would rebuild it. A replacement motor is easy to install, and at the same time replace all the seals in the pump for another $15. This way you will not have to do much if any replumbing and it should work just like it did before. A replacement motor is about half the cost of whole new pump. Usually you can find a replacement motor on Amazon. Watch a couple of youtube videos, it's pretty easy and just make sure you set the motor to run at the correct voltage (otherwise it will let out the smoke in short order).
For comparison I have a 20 x 40 pool w/ 2 skimmers and 2 returns, sand filter and use a 1-1/2 HP Hayward super pump. If you step up to a larger pump you may be able to reduce you running time. If you go to variable speed the operating cost should go down too. If you consider changing to a different pump, make sure your electric service for your pool pump can accommodate it.
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