Schedule Service

HVAC Acronyms and Abbreviations

A – Air, Compressed Air, compressed air line, area
A/C – Air conditioning
ABC – Above ceiling
AC – Air Conditioning air chamber, alternating current
ACD – Automatic Control Damper
AD – Access Door
AF – Air Foil
AFF – Above finished floor
AFG – Above finished grade
AFUE – Annual Fuel Utilization Efficiency
AHU – Air Handling Unit
AL – Aluminum
AMB – Ambient
AMP – Ampere
AP – Access Panel
APD – Air Pressure Drop
ARR – Arrangement
AS – Air Stream
ATC – Automatic Temperature Control
ATM – Atmosphere
AUTO – Automatic
AUX – Auxiliary
AVG – Average
B & S – Bell and spigot
BBD – Boiler blowdown
BDD – Back-Draft Damper
BF – Boiler feed
BHP – Boiler horsepower, brake horsepower
BI – Backwards Inclined
BOD – Bottom of Duct
BOP – Bottom of pipe
BOT – Bottom
BP – Back pressure
BSMT – Basement
BTU – British Thermal Unit
BTUH – British Thermal Unit per Hour
BV – Butterfly valve
C – Condensate line
C to C – Center to center
CA – Compressed air
CAL – Calorie
CAP – Capacity
CD – Condensate drain
CENT – Center, Centrifugal
CF – Cubic Feet chemical feed, cubic foot
CFH – Cubic feet per hour
CFM – Cubic Feet per Minute
CH – Chilled, Chiller
CHW – Chilled Water
CHWR – Chilled Water Return
CHWS – Chilled Water Supply
CI – Cast iron
CIRC – Circular
CL – Center line
CM – Centimeter
CM2 – Square centimeter
CO – Clean out, Carbon Monoxide
COL – Column
CONC – Concrete, concentric
CONN – Connection, Connect
CONT – Continuation
CPVC – Chlorinated polyvinyl chloride
CR – Condenser return
CRW – Chemical resistant waste
CS – Condenser supply
CT – Cooling Tower
CTBD – Cooling Tower Blow Down
CTR – Center
CU – Cubic
CU FT. – Cubic feet
CU IN. – Cubic inches
CUH – Cabinet Unit Heater
CV – Check valve
CW – Cold water
CWR – Condenser Water Return, cold water riser
CWS – Condenser Water Supply
D – Drain, Deep
DB – Dry Bulb {Reference to Temperature}
DDC – Direct Digital Control
DEG – Degree
DELTAT – Temperature difference, Delta Temperature
DET – Detail
DIA – Diameter
DIM – Dimension
DISC – Disconnect
DN – Down
DP – Differential Pressure, Dew point temperature
DR – Drain
DWG – Drawing
E to C – End to center
EA – Each, Exhaust Air
EAHU – Exhaust Air Handling Unit
EAT – Entering Air Temperature
EATR – Exhaust Air Transfer Ratio
EER – Energy efficient ratio
EF – Exhaust Fan
EFF – Efficiency
EJ – Expansion joint
EL – Elevation
ELB – Elbow
ELEC – Electrical
EMER – Emergency
EMS – Energy Management System
ENT – Entering
ERV – Energy Recovery Ventilator
ESP – External Static Pressure
ET – Expansion Tank
EUH – Electrical Unit Heater
EVAP – Evaporator
EWT – Entering Water Temperature
EXH / EX – Exhaust
EXP – Expansion
EXST – existing
EXT – External
F – Fahrenheit
FA – Free Area, Fire Alarm
FC – Flexible Connection, flexible connection
FCO – Floor clean out
FCU – Fan Coil Unit
FD – Floor Drain, Fire Damper, Fire Department
FDW – Feed water
FEC – Fire extinguisher cabinet
FF – Finish floor

FG – Finish grade
FHC – Fire hose cabinet
FLA – Full Load Amps
FLEX – Flexible
FLR – Floor
FLRDR – Floor Drain
FM – Flow meter
FO – Fuel oil
FOV – Flush out valve
FPM – Feet per Minute
FPS – Feet per Second
FRP – Fiberglass Reinforced Plastic
FS – Flow Switch, federal specs
FT – Feet, Foot
FTG – Fitting
FTR – Fin Tube Radiation
FU – Fixture unit
FV – Flush valve
G – Gas, Gram, gas line
GA – Gauge
GAL – Gallons
GALV – Galvanized
GFU – Glycol Feed Unit
GL.V – Globe valve
GND – Ground
GPD – Gallons per day
GPH – Gallons per Hour
GPM – Gallons per Minute
GPS – Gallons per second
GR – Grade, Grain
GV – Gate valve
GWH – Gas water heater
H2O – Water
HB – Hose Bib (Connection)
HD – Head
Hg – Mercury
HGT – Height
HMD – Humidity
HORIZ – Horizontal
HP – Horsepower, High Point
HR – Hour
HRU – Heat Recovery Unit
HRV – Heat Recovery Ventilator
HTD – Heated
HTG – Heating
HTR – Heater
HVAC – Heating Ventilation and Air Conditioning
HW – Hot water
HWH – Hot water heater
HWR – Hot water return, hot water riser
HWS – Hot water supply
HWT – Hot water tank
HZ – Hertz (Cycles per Second)
ID – Inside Diameter
IN – Inches
IN. – Inch
INHg – Inches of mercury
INSUL – Insulation
INT – International
INTL – Internal
IPS – Iron pipe size
IV – Indirect vent
IW – Indirect waste
J – Joule
K – Kelvin
KG – Kilogram
KM – Kilometer
KM2 – Kquare kilometer
KPA – Kilo pascal
KS – Kitchen sink
KW – Kilowatt
L – Length, liter
LAT – Leaving Air Temperature
LB – Pound
LB. – Pound
LBF – Pound
LD – Linear Diffuser
LF – Linear Feet
LIQ – Liquid
LP – Low Point, Low Pressure
LRA – Locked Rotor Amps
LUVR / LVR – Louver
LVDR – Louvered Door
LVG – Leaving
LVL – Level
LVR – Louver
LWT – Leaving Water Temperature
M – Meter
M TYPE – Lightest type of rigid copper pipe
M2 – Square meter
MAN – Manual
MAT – Mixed air temperature
MAX – Maximum
MBH – 1000 BTUH, Thousand British thermal units per hour
MCA – Minimum Circuit Amps
MECH – Mechanical
MFR – Manufacturer
MG – Milligram
MGD – Millions gallons per day
MIN – Minimum, Minute
ML – Milliliter
MM – Millimeter
MM3 – Cubic millimeter
MPT – Male pipe thread
MTD – Mounted
MU – – Make-Up Water
MUA – – Make-Up Air
NA – Not applicable
NC – Noise Criteria, Normally Closed
NEG – Negative
NIC – Not in contact
NO – Normally Open
NOM – Nominal
NPHP – Name plate horsepower
NPS – Nominal pipe size
NPSH – Net positive suction head
NTS – Not to scale
O – Oxygen
OA – Outside Air
OAI – Outside Air Intake
OAT – Outside temperature
OC – On Center
oC – Degrees Celsius
OD – Outside Diameter
ODP – Open Drip Proof

OED – Open end duct
oF – Degrees Fahrenheit
OF – Overflow
OV – Outlet Velocity
OZ. – Ounce
PA – Pascal
PC – Plumbing contractor
PCF – Pounds per Cubic Foot
PCR – Pumped condensate return
PD – Pressure Drop
PF – Power factor
PG – Pressure gauge
PH – Phase
PL – Plate
PNEU – Pneumatic
PRESS – Pressure
PROP – Propeller
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
PV – Plug valve
PVC – Polyvinyl Chloride
QTY – Quantity
R – Radius
R/E – Return and exhaust
RA – Return Air
RAD – Radius
RAT – Return air temperature
RD – Roof drain
RECOV – Recovery
RED – Reducer
REF – Reference
REQD – Required
RET – Return
REV – Revision
RH – Relative Humidity
RL – Refrigerant liquid
RLA – Running Load Amps, Rated Load Amperes
RLF – Relief
RM – Room
RPM – Revolutions per Minute
RS – Refrigerant suction
RTN – Return
RTU – – Roof-Top Unit
RV – Relief valve
S – Switch
SA – Supply Air, Shock absorber
SAT – Supply air temperature
SCH – Schedule
SCR – Screen
SCT – Saturated Condensing Temperature
SD – Smoke Detector, Smoke Damper
SDT – Saturated discharge temperature
SE – Smoke Exhaust
SEC – Seconds, secondary
SEER – Seasonal Energy Efficiency Ratio
SEN / SENS – Sensible
SEP – Separate
SEQ – Sequence
SER – Series
SERV – Service
SF – Square Feet, Service factor
SFD – Combination Smoke / Fire Damper
SHC – Sensible Heat Capacity
SHT – Sheet
SI – International systems of units
SOL – Solenoid
SP – Static Pressure
SPEC – Specification
SPLY – Supply
SQ. – Square
SQ.FT. – Square feet
SS – Stainless Steel
SSH – Static suction head
SST – Saturated suction temperature
STD – Standard
STH – Static total head
STL – Steel
SUCT – Suction
SUP – Supply
SV – Service
SVH – Static velocity head
SW – Service weight
SWS – Service water
T – Temperature, Thermostat
TD – Temperature difference
TDH – Total dynamic head
TEFC – Totally Enclosed Fan Cooled
TEMP – Temperature
TH – Thermometer
THK – Thick
TON – 12,000 BTUH {Cooling Capacity}
TP – Total pressure
TSP – Total Static Pressure
TSTAT – Thermostat
TYP – Typical
UC – Undercut {Door}
UF – Under floor
UH – Unit heater
V – Volts, Vent, Volume
VAC – Vacuum
VAV – Variable Air Volume
VB – Vacuum breaker
VCI – Vacuum cleaning inlet
VCL – Vacuum cleaning line
VD – Volume Damper
VEL – Velocity
VERT – Vertical
VFD – Variable Frequency Drive
VIB – Vibration
VOL – Volume
VP – Velocity pressure
VSD – Variable speed drive
VTR – Vent through roof
W – Watt, width, wide
WB – Wet Bulb Temperature
WC – Water Column
WCO – Wall clean out
WG – Water Gauge
WH – Water heater
WPD – Water Pressure Drop
WTD – Water Temperature Difference

HVAC Acronyms and Abbreviations – Information

The Heating and Cooling industry aka HVAC or “Heating Ventilation and Air Conditioning” has a lot of acronyms and abbreviations.  You may hear an acronyms or abbreviation when looking into a new system, see the acronyms or abbreviation on a sticker or unit and wonder what that means. 

Knowing the acronyms and Abbreviations for HVAC terms can help you when deciding on a new system, an upgrade or understanding Air Conditioning or Furnace terms printed on you system.  We are glad to help with and questions you may have about Heating and Cooling systems.

We would like to help you with a list of related HVAC acronyms and abbreviations with links to other pages on our site to give even more information how the industry is using the term!

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