A good water pump is an integral part of a rainwater harvesting system or water treatment system, without a pump the water doesn't have any pressure.
A water pump is essentially a device that is used to move, and pressurize water in order to perform some kind work. Pumps are the heart of a rainwater harvesting system, moving water to where you need it. Although rainwater harvesting systems powered by gravity, which do not use a pump, are useful in some circumstances, most systems will require a pump to use the rainwater.
Broadly speaking there are two types of water pumps, submersible pumps and inline pumps. Although they essentially perform the same task, they are designed slightly differently.
A submersible pump is designed to be submerged in the water completely, and draws water up through the pump and to the water outlet. The benefits gained by using a submersible pump are:
- It never has to be primed because it is submerged in water
- They don't use energy pulling water into the pump
- They can be easier to install
Inline pumps must be plumbed in between a low pressure water source and the point of usage. The pump will pull water through the inlet and provide pressure at the outlet. Inline pumps are used when high efficiency and maintenance access is required.
On-demand pumps provide PERFECT water pressure to all taps at all times in a standard household. By using a built-in sensor which automatically adjusts pumps speed to match the water consumption while keeping the pressure constant. Submersible pumps and inline pumps are available in on-demand models.