Abbreviations
There are some adding abbreviations that normally used in air conditioning work in addition to the standard that have been use in international standards (S.I):
ahu : Air-Handling Unit
swg : Static water gauge
ach : Air changes (room volumes) per hour
db : dry bulb temperature
wb : wet bulb temperature
dp : dew point temperature
rh : relative humidity
kg/kg : kilogram water vapour per kilogram dry air (absolute moisture content)
TH : Total Heat
SH : Sensible Heat
LH : Latent Heat
SHR : Sensible Heat Ratio
ON OFF: The condition of air or water entering or leaving a coil or heat exchanger
TR: Tons of refrigeration capacity
TRE: Tons of refrigeration capacity extracted
TRR: Tons of refrigeration rejected (at final cooler)
HP: High Pressure (refrigerant)
LH: Low Pressure (refrigerant)
DX: Direct expansion cooling