CHOOSING A PRESSURE SYSTEM PER WATER NEEDS
Residential buildings
The main data needed for calculation of the water needs are given as following:
- the typology of distribution (tab. 1)
- consumption per numbers of outlet (tab.2)
- the simultaneity factor:
The maximum theoretical requirement is given by the sum of the quantities of water delivered to the various typologies of distribution and flats multiplied by the number of them. In practice, it is generally found that only some of the outlets are used simultaneously.
The simultaneity factor allows to define the real maximum delivery that may be required by the typology of distribution.
Non-residential buildings
For calculation of quantities of water required the following types of buildings are considered:
- offices
- shopping centres
- hospitals
- hotels
Choosing a pressure system per delivery head/pressure
The outlet pressure required for proper operation of electrical appliances & sprinklers must not be lower than 1,5 bar and usually not greater then 4-5 bar.
The values to consider for pressure level calculation are the following:
- the geodetic head between the pressure boosting unit and the highest outlet
- the suction lift
- the initial pressure (or positive suction head)
- the minimum residual pressure at the highest outlet (normally 1.5 bar)
- the system head loss
- the difference in pressure between starting and stopping pump