HOW TO SIZE A BOOSTER SYSTEM SET OR PUMP

The first thing to take into consideration when sizing a booster set or pumps is that water bylaws require a break or air gap in the system so that back flow is not created by the new booster system. This is usually achieved through a break tank.

Next you need to look at calculating the flow rate required for the new system. Loading units though not the most precise is perhaps the easiest method of calculating flow rate. Loading units also take into account the appliance and outlets in the system not running simultaneously as is often incorrectly factored into many booster sets. The table and graph below give some indication as to how to correctly measure flow rate.

After flow rate we need the pressure required to move the water its highest point it. Each floor of a building means translates into pressure loss from the mains water supply this is the static head required. Combine this with the friction loss of the system and you get the total dynamic head of the pump required.

The last thing to consider is the set up. The recommended minimum is at least two pumps for most situations as this allows them to alternate increasing the longevity of each pump.