Finding the right water pump can be a bit confusing for the uninitiated, especially with the huge variety of well pumps on the market today. The difference between 1HP and 0.5HP water pump comes down to the type of motor used. A 1HP pump motor uses a larger motor than a 0.5HP pump motor, and that 1HP motor will consume twice as much power. A 1HP water pump will therefore be able to pump from deeper wells, and pump higher flow rates than the 05.HP water pump could.
Let's look at approximate power consumption between the two pumps…
1HP = 746 watts
0.5HP = 373 watts
If you use a 1HP water pump over a .5HP water pump, expect higher electricity usage, and in turn the electricity bill will cost more.
Why Use a 1HP water pump vs a 0.5HP water pump?
Your well depth and intended pump application will determine what size of pump you use. A water pump is sized using a total dynamic head calculation…
Well depth + vertical lift + frictional loss + head from use of a pressure tank
A 1HP pump is used in situations with total dynamic heads up to 500 feet.
A .5HP pump is used in situations with total dynamic heads up to 250 feet.
Let's take a look at a couple examples of 1HP and 05.HP RPS model water pumps. You’ll notice that the 05RPS05, a .5HP water pump, and the 05RPS10, a 1 HP water pump, are from the same model line of pumps that produce up to 2-8GPM. However, a 1HP water pump will outperform the .5HP by producing more water at every level of total dynamic, and provide a higher total head that's double the .5HP.
|
05RPS05 (1/2HP) |
05RPS10 (1HP) |
|
|
50 |
8.00 |
8.00 |
|
100 |
7.00 |
8.00 |
|
150 |
6.50 |
8.00 |
|
200 |
5.50 |
7.50 |
|
250 |
4.50 |
7.00 |
|
300 |
3.00 |
6.50 |
|
350 |
1.00 |
5.50 |
|
400 |
5.00 |
|
|
450 |
4.50 |
|
|
500 |
3.50 |
|
|
550 |
2.50 |
|
|
600 |
1.00 |
Let’s take a look at another comparison of a 0.5HP water pump and a 1HP from the same model line, this time 3-13GPM. Again, unsurprisingly the 1HP 07RPS10 outperforms the .5HP 07RPS05.
|
07RPS05 (1/2HP) |
07RPS10 (1HP) |
|
|
50 |
13.20 |
13.20 |
|
100 |
12.00 |
13.20 |
|
150 |
10.50 |
12.50 |
|
200 |
8.00 |
11.50 |
|
250 |
4.50 |
10.50 |
|
300 |
0.00 |
9.00 |
|
350 |
7.50 |
|
|
400 |
5.50 |
|
|
450 |
3.50 |
|
|
500 |
0.50 |
|
|
550 |
||
|
600 |
