You won’t need a very powerful water pump to lift 20 feet. If you’re pumping out of a well, I would say a 1/2 HP or 3/4HP submersible pump will easily be up to the task.
The next question you’d need to ask yourself is… how many gallons per minute of water do you need?
A submersible pump for a household would typically require at least 10-15 gallons per minute. In that case I would recommend something like a 07RPS05 1/2HP or a 07RPS07 3/4HP. If you wanted a higher flow rate, around 25GPM, then I’d recommend a 25RPS05 1/2HP.
And then the next question after that is, do you plan on using a pressure tank?
A 40-60psi pressure tank will INCREASE the workload of a pump by 92 to 140 feet. Here’s the math of translating PSI into feet of head…
1PSI = 2.31 feet of head
40 PSI = 92 feet of head
50 PSI= 115 feet of head
60 PSI = 140 feet of head
In that case, here’s the math for a 20 foot lift with a 40PSI pressure tank…
20 feet of lift + 140 feet from a 60 PSI pressure tank = 160 feet total head
In the case of a well for a residence that needs to pump at least 10-15 gallons per minute and handle at least 160 feet of head, I’d still recommend around a 3/4HP to 1HP, like a 07RPS07 or a 07RPS10. Just like before, if you wanted around 25GPM flow rate, then a 25RPS10 1HP or 25RPS15 1.5HP would be the right fit.
As an alternative, a surface booster pump can easily pump 20 feet of lift. Any of the booster pumps from the RPS Eco-Steady Booster Pump Range will pump up to storage tanks, to homes, or transfer water.
Want to learn more about well pump sizing, or the downsides of oversizing a pump? Take a look at this article on whether it is better to oversize or undersize a submersible pump.
