Measurement Guide

Grundfos cannot be held responsible for wrong sizing based on this guide. If any questions to selection or sizing please feel free to contact us any time or go to grundfos.us DN000430_1220
GROUNDWATER  QUICK SIZING  PUMP
FLOW SIZING
HEAD SIZING
PUMP SELECTION
Kitchen sink
Dish washer,
washing
machine
Toilet w.
wash basin
and WC
Bathroom w.
wash basin,
WC and
shower
Bathroom w.
wash basin,
WC and
bathtub
Garden
and lawn
irrigation
Nominal
ow
[m
3
/h]
Recommended
pump size
Small house 1 1 1 SQ1
Medium house 1 2 1 1 2 SQ2
Large house 2 2 1 1 2 3 SQ3
2 x large house 5 SQ5
3 x large house 7 SQ7
SQ
· Compact design
· Built-in motor
protection
· Easy installation
H [m]P [kPa]
Q [m
3
/h]0,0
0
10
20
200
400
600
800
1000
1200
1400
30
40
50
60
70
80
90
100
110
120
130
140
150
0,4 0,8 1,2 1,6 2,0 2,4 2,8 3,2 3,6 4,0 4,4
-35
-55
-70
-85
-100
-105
75m
2,0 m
3
/h
Level of highest
taping point
Level of house
oor level
Level of well head
Dynamic water level
C (5 m)
B (5 m)
A (20 m)
Calculate max. pressure required
1. Pressure (H) at the tap requiring max. pressure = X
2. Static head (A + B + C) = Y
3. Pressure loss from friction in pipes and ttings = Z
H
total
= X + Y + Z
Example of calculation
1. Pressure at the tap (max pressure ): 3 bar = 30 m
2. Static head: 20 m +5 m+5 m = 30 m
3. Pressure loss from friction in pipes and ttings:
10 m+5 m = 15 m
Maximum pressure required:
H
total
= 30 m + 30 m + 15 m = 75 m
Pressure loss from friction in pipes and ttings.
Outside the house: plastic pipe, Ø25, length 44 m => 10 m
Inside the house => 5 m
Pump choice
SQ 2 - 70
Medium house
=> Nominal ow 2 m
3
/h => Pump size SQ2
Example of ow sizing
Quick selection guide
GRUNDFOS DOMESTIC COLD WATER