Worcester 28Si User Manual

5
GAS SUPPLY SYSTEM - BASED ON NG (G20)
TOTAL LENGTH OF GAS SUPPLY PIPE (COPPER) metres
3 6 9 12
GAS DISCHARGE RATE - PRESSURE DROP 1mbar. m
3
/h PIPE DIAMETER mm
8.7 5.8 4.6 3.9 22
18.0 12.0 9.4 8.0 28
Table 7
CLEARANCES (mm)
INSTALLATION SERVICE
ABOVE APPLIANCE AND/OR FLUE ELBOW 30 30
IN FRONT OF APPLIANCE 600 600
BENEATH APPLIANCE 200 200
RIGHT AND LEFT HAND SIDE 10 10
Table 8
SYSTEM CAPACITY
TOTAL SYSTEM VOLUME litres
INITIAL INITIAL CHARGE PRESSURE bar
PRESSURE bar 0.5 1.0 1.5
1.0 57 75 N/A
1.5 31 42 52
Table 9
PERFORMANCE SPECIFICATIONS 25Si 28Si
PRIMARY WATER CAPACITY litres 2.0 2.0
MAXIMUM MAINS INLET PRESSURE bar 10 10
MINIMUM MAINS INLET PRESSURE (WORKING) FOR MAXIMUM FLOW bar 1.1 1.3
MINIMUM MAINS INLET PRESSURE (WORKING) FOR OPERATION bar 0.5 0.5
DOMESTIC HOT WATER TEMPERATURE RANGE °C 40 - 62 40 - 62
MAXIMUM CENTRAL HEATING FLOW TEMPERATURE °C 82 (nom) 82 (nom)
MAXIMUM CENTRAL HEATING SYSTEM SET PRESSURE bar 2.5 2.5
MINIMUM CENTRAL HEATING SYSTEM PRESSURE bar 1 1
OUTPUT TO DOMESTIC HOT WATER kw NATURAL GAS (G20) 8.5 - 25 8.5 - 28.0
LPG - PROPANE (G31) 8.5 - 25 8.5 - 28.0
OUTPUT TO CENTRAL HEATING kw NATURAL GAS (G20) 8.5 - 25 8.5 - 28.0
LPG - PROPANE (G31) 8.5 - 25 8.5 - 28.0
DOMESTIC HOT WATER SPECIFIC RATE - 30°C RISE l/min 12.0 13.4
MAXIMUM DOMESTIC HOT WATER FLOW RATE - 40°C RISE l/min 9.0 10.0
NOx CLASSIFICATION FOR BOTH 25 & 28Si Class 2
SEDBUK NUMBER 78.0 78.2
SEDBUK BAND D D
Table 5
Refer to Section 6.
DOMESTIC HOT WATER TEMPERATURE RISE
DISCHARGE RATE l/min 7 8 9 10
TEMPERATURE RISE °C 25Si 51 45 40 36
TEMPERATURE RISE °C 28Si 57 50 45 40
Table 6

Worcester 28Si Specifications

General

Model	28Si
Output	28kW
Efficiency Rating	A
ErP Rating	A
Flow Rate	11.4 l/min
Water Pressure	3 bar
Max Gas Rate	2.8 m3/h