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How can I verify my water supply is sufficient for my fire sprinkler or watermist suppression system?

The typical water flow in the UK household is 10 to 25 lpm. As Automist does not require more water than taken by a standard household appliance, it can be installed in the vast majority of homes without a water infrastructure upgrade. Automist must be connected to a reliable water supply, which delivers 8 litres per minute (lpm) flow at a minimum of 1.5 bar (150kPa) and a maximum of 16 bar (1.6 MPa) static pressure at the point of connection. The pump only requires only 6 lpm and 1 bar pressure, so a safety margin is embedded in this requirement. All other systems on the market require at least 12 litres of water per minute flow at the point of connection. This requirement for traditional systems increases with the number of nozzles in an area because of the assumed maximum area of operation (AMAO).

Required flow rate at the point of connection for a domestic fire sprinkler (category 1) or suppression system:

No. of heads in a single room

Required flow rate at the point of connection


Ceiling mounted watermist

Ceiling mounted sprinkler

1 (e.g. <35 sqm)

8 lpm

13.8 lpm

66 lpm (49 lpm low flow head)

2 (e.g. >35 sqm)

8 lpm

13.8 lpm

105 lpm


To obtain the appropriate flow, if you do not opt for Automist, you will require the following:
1)    Permission from the water authority for direct connection to the town main and/or
2)    Installation of a priority valve (~£300) and/or
3)    Installation of a large, stored water tank (~£1200)

Read next - What questions should you ask when comparing fire sprinkler / watermist suppression quotes?