Full Product Manual

Operating conditions
6
Grundfos COMFORT
2
2. Operating conditions
Pumped liquids
• Thin, clean, non-aggressive and non-explosive
liquids without solid particles or fibres
• Cooling liquids, not containing mineral oil
• Domestic hot water
• Softened water.
The kinematic viscosity of water is 1 mm
2
/s (1 cSt) at
20 °C. If the pump is used for a liquid with a higher
viscosity, the hydraulic performance of the pump will
be reduced.
Example: 50 % glycol at 20 °C means a viscosity of
approx. 10 mm
2
/s, reducing pump performance by
approx. 15 %.
When selecting a pump, the viscosity of the pumped
liquid must be taken into account.
Temperatures
Liquid temperature
Liquid temperature range: 2 to 95 °C.
Operating temperature
We recommend that you keep the operating
temperature around 50 °C to minimise build-up of lime
deposits. Be aware of the risk of legionella
contamination.
Ambient temperature
The ambient temperature must always be lower than
the liquid temperature to minimise condensation in the
stator housing, and not exceed 40 °C.
Pressures
System pressure
Maximum system pressure (PN 10): 1.0 MPa (10 bar/
145 psi).
Inlet pressure
To prevent cavitation noise and damage to the pump
bearing, a minimum inlet pressure of 0.5 bar (5 m
head) is required at the pump suction port.
Pump location
Indoors, in a non-aggressive and non-explosive
atmosphere.
Relative air humidity: Maximum 95 %.