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Table 1: Typical pressure drops through an
air handling unit
Device Pressure drop
Panel filter 120 Pa (dirty)
Bag filter 200 Pa (dirty)
Thermal wheel 120 Pa
Cooling coil 80 Pa (plus eliminator)
Heating coil 10 Pa (single row)
Silencer 50 Pa each (for supply
and extract)
Heat recovery devices 200 Pa
Terminals 150 Pa (per box)
Run around coils 60 Pa
Table 2: ECON 19 benchmark generator related to fan power
Benchmark Good
practice
      Typical
practice
     
Office type1 Type 1 Type 2 Type 3 Type 4 Type 1 Type 2 Type 3 Type 4
W/l/s 1·0 1·0 2·0 2·0 1·5 1·5 3·0 3·0
l/s/m2 (average) 0·2 0·3 4·0 4·0 0·2 0·3 4·0 4·0
W/m2 0·2 0·3 8·0 8·0 0·3 0·5 12 12
h/y 2500 2500 2750 3000 3000 3000 3500 3700
kWh/m2 tfa* 0·5 0·8 22 24 0·9 1·4 42 44
*Treated floor area                
1Type 1: Naturally ventilated cellular                
Type 2: Naturally ventilated open-plan                
Type 3: Air conditioned standard                
Type 4: Air conditioned prestige