HVAC Acronyms and Abbreviations

Here’s a list we’ve compiled of many of the HVAC acronyms and HVAC abbreviations that are seen regularly.

Acronym What it stands for …
AC Air Conditioning
AC Alternating Current
ACH Air Changes per Hour
ACM Asbestos Containing Material
AEE Association of Energy Engineers
AFD Adjustable Frequency Drive
AFUE Annual Fuel Efficiency Ratio
AHU Air Handling Unit
AI Analog Input
AO Analog Output
ASHRAE American Society of Heating Refrigeration and Air Conditioning Engineers
B Boiler
BACnet A Data Communication Protocol for Building Automation and Control Networks
BAS Building Automation System
BCA Building Commissioning Association
BI Backward Incline
BI Binary Input
BO Binary Output
BSLN Baseline
BTU British Thermal Unit
BTUH Brtish Thermal Units / Hour
BY Base Year
CAV Constant Air Volume
CD Cold Deck
CDD Cooling Degree Days
CEM Certified Energy Manager
CFC ChloroFluoroCarbon
CFM Cubic Feet per Minute
CH Chiller
CHW Chilled Water
CHWP Chilled Water Pump
CHWR Chilled Water Return
CHWRT Chilled Water Return Temperature
CHWS Chilled Water Supply
CHWST Chilled Water Supply Temperature
CLF Cooling Load Factor
CLTD Cooling Load Temperature Difference
COP Coefficient Of Performance
CRAC Computer Room Air Conditioner
CT Cooling Tower
CV Constant Volume
CVRMSE Coefficient of Variation of the Root Mean Square of the Error
CWP Condenser Water Pump
CWR Condenser Water Return
CWRT Condenser Water Return Temperature
CWS Condenser Water Supply
CWST Condenser Water Supply Temperature
CY Current Year
DA Discharge Air
DB Data Base
DB Dry Bulb
DC Direct Current
DCV Demand Controlled Ventilation
DD Degree Day
DDC Direct Digital Control
DH Duct Heater
DI Digital Input
DO Digital Output
DP Dew Point
DP Differential Pressure
DX Direct Expansion
EAT Entering Air Temperature
ECM Electronically Commutated Motor
ECM Energy Conservation Measure
ECO Energy Conservation Opportunity
EDH Electric Duct Heater
EEM Energy Efficiency Measure
EER Energy Efficiency Ratio
EF Exhaust Fan
EH Electric Heater
EMS Energy Management System
ESCO Energy Service Company
EUH Electric Unit Heater
EWT Entering Water Temperature
FC Forward Curve
FCU Fan Coil Unit
FIM Facility Improvement Measure
FLA Full Load Amps
FMS Facility Management System
FPM Feet Per Minute
FW Feed Water
GPM Gallons Per Minute
GUI Graphical User Interface
HCFC Hydrochlorocfuorocarbon
HD Hot Deck
HDD Heating Degree Days
HEPA High Efficiency Particulate Arresting
HFC HydroFluoroCarbon
HHV Higher Heating Value
HHWP Heating Hot Water Pump
HHWR Heating Hot Water Return
HHWS Heating Hot Water Supply
HL High Limit
HPS High Pressure Steam
HR Heat Recovery
HRU Heat Recovery Unit
HRV Heat Recovery Ventilator
HSPF Heating Seasonal Performance Factor
HVAC Heating Ventilation and Air Conditioning
HWP Hot Water Pump
HWR Hot Water Return
HWS Hot Water Supply
HWRT Hot Water Return Temperature
HWST Hot Water Supply Temperature
HX Heat Exchanger
I/O Input Output
IAQ Indoor Air Quality
IPMVP International Performance Measurement and Verification Protocol
IR Infra-Red
LAT Leaving Air Temperature
LHV Lower Heating Value
LL Low Limit
LON Local Operating Network
LP Low Pressure
LPS Low Pressure Steam
LRA Locked Rotor Amps
LWBT Leaving Wet Bulb Temperature
LWT Leaving Water Temperature
M&V Measurement and Verification
MA Mixed Air
MAT Mixed Air Temperature
MCC Motor Control Center
MUA Make-up Air Unit
MX Metrix Utility Accounting System
MZ Multi-Zone
NC Normally Closed
NEMA National Electrical Manufacturers Association
NO Normally Open
NPSH Net Positive Suction Head
OA Outside Air
OAP Outside Air Percentage
OAT Outside Air Temperature
ODP Open Drip Proof
OWS Operator Work Station
PC Performance Contracting
PE Professional Engineer
PH Pre-Heat
PID Proportional Integral Derivative
PRV Pressure Relief Valve
PRV Pressure Reducing Valve
PTAC Packaged Terminal Air Conditioner
RA Return Air
RF Return Fan
RH Reheat
RH Relative Humidity
RPM Revolutions Per Minute
RTD Resistance Temperature Detector
RTU Roof Top Unit
SA Supply Air
SAT Supply Air Temperature
SC Shading Coefficient
SEER Seasonal Energy Efficiency Ratio
SF Supply Fan
SHFG Solar Heat Gain Factor
SHR Sensible Heat Ratio
SP Set Point
SP Static Pressure
SWP Steam Working Pressure
T Temperature
T Thermostat
TEV Thermostatic Expansion Valve
TOD Time Of Day
TORR Millimeter of Mercury (mmHg)
TXV Thermostatic Expansion Valve
UH Unit Heater
UV UltraViolet
UV Unit Ventilator
VAV Variable Air Volume
VD Volume Damper
VFD Variable Frequency Drive
VSD Variable Speed Drive
VSP Variable Speed Pump(ing)
WB Wet Bulb
WC Water Column
YTD Year To Date