The list of HVAC abbreviations used in a set of engineering drawings varies from office to office. Be sure to check the front section of the construction drawing set for the abbreviations used within.
A | Air or Compressed Air |
AC | Air Conditioning |
ACD | Automatic Control Damper |
AD | Access Door |
AF | Air Foil |
AHU | Air Handling Unit |
AMP | Ampere |
AP | Access Panel |
APD | Air Pressure Drop |
AS | Air Stream |
ATC | Automatic Temperature Control |
ATM | Atmosphere |
BDD | Back-Draft Damper |
BHP | Brake Horsepower |
BI | Backwards Inclined |
BOD | Bottom of Duct |
BTU | British Thermal Unit |
BTUH | BTU per Hour |
CENT | Center or Centrifugal |
CF | Cubic Feet |
CFM | Cubic Feet per Minute |
CH | Chilled or Chiller |
CHW | Chilled Water |
CHWR | Chilled Water Return |
CHWS | Chilled Water Supply |
CO | Carbon Monoxide |
CONN | Connection |
CPT | Compressor Protector Terminal |
CT | Cooling Tower |
CTBD | Cooling Tower Blow Down |
CUH | Cabinet Unit Heater |
CWR | Condenser Water Return |
CWS | Condenser Water Supply |
D | Drain |
DB | Dry Bulb (Temperature) |
DEG | Degree |
DDC | Direct Digital Control |
DIA | Diameter |
DIM | Dimension |
DP | Differential Pressure |
EA | Each or Exhaust Air |
EAHU | Exhaust Air Handling Unit |
EAT | Entering Air Temperature |
EF | Exhaust Fan |
EMER | Emergency |
EMS | Energy Management System |
ESP | External Static Pressure |
ET | Expansion Tank |
EUH | Electrical Unit Heater |
EWT | Entering Water Temperature |
EXH or EX | Exhaust |
EXT | External |
EXP | Expansion |
F | Fahrenheit |
FA | Free Area or Fire Alarm |
FC | Flexible Connection |
FCU | Fan Coil Unit |
FD | Floor Drain, Fire Damper, or Fire Department |
FLA | Full Load Amps |
FLEX | Flexible |
FLRDR | Floor Drain |
FPM | Feet per Minute |
FPS | Feet per Second |
FRP | Fiberglass Reinforced Plastic |
FS | Flow Switch |
FT | Feet |
FTR | Fin Tube Radiation |
G | Gas |
GA | Gauge |
GAL | Gallons |
GALV | Galvanized |
GFU | Glycol Feed Unit |
GPH | Gallons per Hour |
GPM | Gallons per Minute |
GR | Grade |
HB | Hose Bib (Connection) |
HD | Head |
HP | Horsepower or High Point |
HR | Hour |
HRU | Heat Recovery Unit |
HTG | Heating |
HWR | Hot Water Return |
HWS | Hot Water Supply |
HZ | Hertz (Cycles per Second) |
ID | Inside Diameter |
IN | Inches |
KW | Kilowatt |
LAT | Leaving Air Temperature |
LB | Pound |
LF | Linear Feet |
LD | Linear Diffuser |
LP | Low Point |
LPS | Low Pressure Steam |
LRA | Locked Rotor Amps |
LUVR or LVR | Louver |
LVDR | Louvered Door |
LVG | Leaving |
LWT | Leaving Water Temperature |
MAX | Maximum |
MBH | 1000 BTUH |
MCA | Minimum Circuit Amps |
MD | Motorized Damper |
MECH | Mechanical |
MIN | Minimum |
MU | Make-Up Water |
MUA | Make-Up Air |
NC | Noise Criteria or Normally Closed |
NO | Normally Open |
NOM | Nominal |
OA | Outside Air |
OAI | Outside Air Intake |
OC | On Center |
OD | Outside Diameter |
ODP | Open Drip Proof |
OV | Outlet Velocity |
PCF | Pounds per Cubic Foot |
PD | Pressure Drop |
PH | Phase |
PRV | Pressure Reducing Valve |
PSI | Pounds per Square Inch |
PSIA | Pounds per Square Inch - Absolute |
PSID | Pounds per Square Inch - Differential |
PSIG | Pounds per Square Inch - Gauge |
PVC | Polyvinyl Chloride |
R | Radius |
RA | Return Air |
RET | Return |
RH | Relative Humidity |
RLA | Running Load Amps |
RLF | Relief |
RPM | Revolutions per Minute |
RTU | Roof-Top Unit |
SA | Supply Air |
SCR | Screen |
SCT | Saturated Condensing Temperature |
SD | Smoke Detector or Smoke Damper |
SE | Smoke Exhaust |
SEN | Sensible |
SFD | Combination Smoke / Fire Damper |
SHC | Sensible Heat Capacity |
SP | Static Pressure |
SF | Square Feet |
SS | Stainless Steel |
SUP | Supply |
T | Temperature or Thermostat |
TEFC | Totally Enclosed Fan Cooled |
TEMP | Temperature |
TON | 12,000 BTUH (Cooling Capacity) |
TSP | Total Static Pressure |
TSTAT | Thermostat |
TYP | Typical |
UC | Undercut (Door) |
V | Volts |
VAV | Variable Air Volume |
VD | Volume Damper |
VEL | Velocity |
VFD | Variable Frequency Drive |
WB | Wet Bulb Temperature |
WC | Water Column |
WG | Water Gauge |
WPD | Water Pressure Drop |
WTD | Water Temperature Difference |