2-W =2-Way
3-W =3-Way
AF =Air Filter
AF =Airfoil
APD =Air Pressure Drop
AS =Air Separator
AS =Air-Side
AV =Air Vent
B =Boiler
BD =Balance Damper
BHP =Brake Horsepower
bhp =Boiler Horsepower
BI =Backward Included
BTU =British Thermal Unit
BTUH =British Thermal Unit/Hour
CAV =Constant Air Volume
CC =Cooling Coil
CCV =Cooling Control Valve
CF =Cubic Foot
CFM =Cubic Feet Per Minute
CHWR =Chilled Water Return
CHWS =Chilled Water Supply
CO =Cleanout
COND =Condensate
CS =Constant Speed
CT =Cooling Tower
CV =Control Valve
CWR =Condenser Water Return
CWS =Condenser Water Supply
D =Density
dB =Dry Bulb
DP =Dew Point
EAT =Entering Air Temperature
EG =Ethylene Glycol
ET =Expansion Tank
EWC =Electric Water Cooler
EWT =Entering Water Temperature
FC =Forward Curved
FD =Floor Drain
FMBD =Flow Meter/Balancing Device
FPM =Feet Per Minute
FS =Floor Sink
ft2 =Square Foot
ft3 =Cubic Foot
FU =Fixture Units (Plumbing)
GPH =Gallons Per Hour
GPM =Gallons Per Minute
h =Enthalpy
HC =Heating Coil
HCV =Heating Control Valve
HP =Horsepower
HWR =Heating Water Return
HWS =Heating Water Supply
HXER =Heat Exchanger
KS =Kitchen Sink
kW =Kilowatt
kWh =Kilowatt Per Hour
LAT =Leaving Air Temperature
LAV =Lavatory
lb/hr =Pounds Per Hour
LWT =Leaving Water Temperature
MAT =Mixed Air Temperature
MOD =Motor Operated Damper
NPSH =Net Positive Suction Head
OA =Outside Air
OAT =Outside Air Temperature
OPD =Opposed Blade Damper
ORD =Overflow Roof Drain
P =Pump
PBD =Parallel Blade Damper
PD =Pressure Drop
PG =Propylene Glycol
PPH =Pounds Per Hour
PSI =Pounds Per Square Inch
PSIG =Pounds Per Square Inch Gage
RA =Return Air
RAF =Return Air Fan
RAT =Return Air Temperature
RD =Roof Drain
RH =Relative Humidity
RLFA =Relief Air
RPM =Revolutions Per Minute
SA =Supply Air
SAF =Supply Air Fan
SAT =Supply Air Temperature
SF =Square Foot
SHW =Shower
SP =Static Pressure
SS =Steam-Side
ST =Storage Tank
STM =Steam
TC =Terminal Cooling
TH =Terminal Heating
TP =Trap Primer
UR =Urinal
V =Specific Volume
VAV =Variable Air Volume
VD =Volume Damper
VFD =Variable Frequency Drive
VP =Velocity Pressure
VS =Variable Speed
W =Humidity Ratio
wB =Wet Bulb
WC =Water Closet
WH =Water Heater
WPD =Water Pressure Drop
WS =Water-Side
WS =Water Softener