HVAC Career

Meanings of commonly used HVAC control symbols

Outlined below are the most commonly used hvac control symbols and their meanings.

Click here to view easy-to-use compiled charts of these symbols.

pressure sensor symbol

pressure sensor

Measures pressure of gases or liquids.

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VARIABLE SPEED DRIVE

VSD enables variable control of motor speed and torque so that hvac systems can run at optimum efficiency.

Flow switch symbol

Flow switch

Flow switches trip pumps on or off to control fluid flow.

air conditioning symbol

Air conditioning controller

An electronic module that controls the hvac system.

carbon monoxide sensor symbol

carbon monoxide sensor

Sensors used to measure and thereby limit carbon monoxide.

co2 sensor symbol

co2 sensor

Used to measure CO2 concentration in air and adjust ventilation system accordingly.

DIFFERENTIAL PRESSURE TRANSDUCER symbol

DIFFERENTIAL PRESSURE TRANSDUCER

DPTs measure pressure difference across a region and aid in hvac zones systems such as stairwell pressurization, lift pressurization ,etc.

building management system symbol

BUILDING MANAGEMENT SYSTEM

BMS is a computer based system that monitors the equipment systems of a building.

relative humidity sensor symbol

Relative Humidity sensor

Measures relative humidity of air.

Velocity meter symbol

Velocity meter

Measures air velocity in ducts.

flow meter symbol

FLOW METER

Measures flow in ducts and pipes.

Top to bottom symbol

Top to bottom

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side to side

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side to bottom

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Damper

Dampers are used to regulate airflow.

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VAV Box

VAV boxes regulate air flow through a duct.

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THERMAL Energy Meter

Thermal Energy Meters measure amount of energy content in chilled water liquid flow.

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Heat Exchanger

Heat exchanger is a device that transfers thermal energy from one medium to another.

Meanings of commonly used HVAC piping symbols

Outlined below are the most commonly used hvac piping symbols and their meanings.

Click here to view easy-to-use compiled charts of these symbols.

chilled water supply line symbol

CHILLED WATER SUPPLY

chilled water return line symbol

CHILLED WATER RETURN

hot water supply line symbol

HOT WATER SUPPLY

hot water return line symbol

HOT WATER RETURN

cold water supply symbol

COLD WATER SUPPLY

cold water return symbol

COLD WATER RETURN

refrigerant line symbol

REFRIGERANT LINE

makeup water line symbol

MAKEUP WATER LINE

humidification line symbol

HUMIDIFICATION LINE

drain pipe line symbol

DRAIN PIPE

vent pipe line symbol

VENT PIPE

pressure gauge symbol

PRESSURE GAUGE

automatic air vent symbol

AUTOMATIC AIR VENT

test point symbol

TEST POINT

pipe riser-dropper symbol

PIPE RISER/DROPPER

flow direction line symbol

FLOW DIRECTION

flexible pipe connection symbol

FLEXIBLE PIPE CONNECTION

temperature gauge symbol

TEMPERATURE GAUGE

strainer symbol

STRAINER

Meanings of commonly used HVAC Ductwork symbols

Outlined below are the most commonly used hvac ductwork symbols and their meanings.

Click here to view easy-to-use compiled charts of these symbols.

Duct Symbol

Straight duct

Ducts are conduits or passages used in hvac systems to move air.

Duct Branch symbol

branch duct

In order to split air passage among spaces, branch ducts are used.

Duct Bend

duct bend

In order to make smooth turns and avoid turbulence bend pieces are used in the air passage.

Duct Y junction

y-junction

3-way junction duct

3-way junction

duct junction

junction

duct beveled junction

beveled junction

Such junctions are used when a part of the air from the main passage is diverted to a certain space.

duct miter bend

miter bend

A miter bend(elbow) is made by mitering or bevel cutting two pipes or ducts usually to form a 90 degree turn.

Duct Transition

Duct Transition

Used to reduce to effective diameter of a duct. Transitions are required to change the overall size or shape of a duct.

Duct offset Transition

Duct offset Transition

Supply Ceiling Diffuser

Supply Ceiling Diffuser

Distributes conditioned air uniformly throughout the room. These are visible on the ceiling.

Return Ceiling Diffuser

Return Ceiling Diffuser

Collects return air from the room. These are visible on the ceiling.

Flexible Connector Duct

Flexible Connector

Flexible connectors are used as attachments between ducts and equipment in order to reduce noise and vibration.

VAV Box symbol

VAV Box

Variable Air Volume(VAV) boxes maintain the temperature of a space by controlling the supply of conditioned air through the duct into the space.

duct damper symbols

Duct Damper

Duct dampers are control devices in ducts that function like butterfly valves to control airflow.

Linear diffuser symbols

Linear Diffuser Supply/Return

Linear diffusers distribute air evenly throughout a space.

Floor Register

Floor Register

A register is a grille with air flow adjustment.

Air grilles symbols

Air grilles

Air grilles are used to evenly distribute air in a space.

duct heater symbol

Duct Heater

Used to heat air flowing through a duct.

duct flexible connection

Flexible Connection

Used to reduce noise and vibration.

duct louver opening

Louver Opening

Louver is a device used in hvac ventilation systems to allow air to pass through while keeping out dirt and debris.

new ductwork symbol

New Ductwork

insulated ductwork symbol

INSULATED DUCTWORK

Insulated ducts are used to reduce thermal energy loss and prevent condensation on ducts.

externally insulated duct symbol

EXTERNALLY INSULATED DUCTWORK

Insulated ducts are used to reduce thermal energy loss and prevent condensation on ducts.

fire rated duct symbol

FIRE RATED DUCT SYMBOL

Fire resistant ducts help maintain compartmentalization and divert smoke.

volume control damper symbol

volume control damper

Used to control volume of air passing through a duct.

fire damper symbol

fire damper

Fire dampers are fire protection devices used to prevent spread of fire through ducts.

duct flexible connection symbol

flexible connection

duct spigot with butterfly damper

duct spigot with butterfly damper

non return damper

non return damper

Non return dampers ensure airflow in single direction

duct attenuator symbol

duct mounted attenuator

Used near AHUs/FAHUs to reduce transmission of noise.

Motorised damper symbol

Motorised damper/ motorised smoke & fire damper

Performs the same function as a regular damper but is motorised and can be controlled automatically.

circular flexible duct symbol

circular flexible duct

duct riser symbol

DUCT RISER

Duct that rises vertically through a building or structure.

duct dropper symbol

DUCT DROPPER

Duct that drops vertically through a building or structure.

duct acoustic lining symbol

duct acoustic lining

Duct acoustic liners are primarily used for sound absorption.

vertical duct section symbol

vertical duct section

circular diffuser symbol

circular diffuser

supply duct section symbol

supply duct section

return duct section symbol

return duct section symbol

Meanings of commonly used HVAC equipment symbols

Outlined below are the most commonly used hvac equipment symbols and their meanings.

Click here to view easy-to-use compiled charts of these symbols.

FCU Symbol

fcu

Fan Coil Unit is a device that heats or cools a space using a coil and a fan.

AHU symbol

ahu

Air Handling Unit (AHU) is a device used to circulate air in an hvac system.

chiller symbol

chiller

Chiller is a device that removes heat from a liquid by making use of the VCR cycle.

pump symbol

pump

In hvac systems pumps are used to pressurize and movie liquid along hydronic lines.

compressor symbol

compressor

In hvac systems, the compressor compresses the refrigerant.

fan symbol

fan

Different types of fans are used in hvac systems. Each performs a different function.

cooling coil symbol

cooling coil

Cooling coils remove heat from the air.

silencer symbol

silencer

Silencers reduce airborne noise.

muffler symbol

muffler

Mufflers in hvac systems reduce noise by dampening gas pulsations in compressor suction and discharge lines.

air filter symbol

air filter

Air filter collects dust and debris while letting air pass through.

DX unit symbol

dx unit

A direct expansion air conditioning unit(DX unit), cools air using a refrigerant liquid.

dryer symbol

dryer

The dryer in hvac systems absorb extra moisture.

condenser symbol

condenser

The condenser is the component of the hvac system that removes heat from the refrigerant.

temperature sensor symbol

temperature sensor

cooling tower symbol

cooling tower

Cooling towers in hvac systems remove heat from water that is pumped to it from the condenser.

solenoid valve symbol

solenoid valve

Solenoid valve is an electromechanical valve that can be used to turn refrigerant flow on and off.

gate valve symbol

gate valve

Gate valves are used to fully open or close flow.

globe valve symbol

globe valve

Globe valves can be used to regulate flow.

butterfly valve symbol

butterfly valve

Butterfly valves are used to regulate flow.

check valve symbol

Check valve

Check valves ensure that flow occurs only in one direction.

250 HVAC Acronyms

HVAC stands for Heating, Ventilation and Air Conditioning. Aside from HVAC full form, knowledge of key terms like equipment abbreviation and air conditioning symbols is of paramount importance in MEP industry. Having a stronghold over hvac basics is necessary when building a foundation. Here, we have compiled a list of 250 of the most commonly used acronyms in the HVAC industry (mainly in hvac design). These abbreviations and hvac full forms may appear in daily use situations and hence any passionate HVAC engineer must be familiar with these terms.

Acronym-Expansion

AAV-Automatic Air Vent

ABC-Above Ceiling

ACH-Air Changes per Hour

A/C-Air Conditioning/Air Curtain

AFF-Above Finished Floor

AFG-Above Finished Grade

ACD-Automatic Control Damper

AD-Access Door

AMB-Ambient

AF-Air Foil

AFU-E-Annual Fuel Utilization Efficiency

AHR-I-Air Conditioning, Heating, and Refrigeration Institute

AHU-Air Handling Unit

ASHRAE-American Society of Heating, Refrigerating and Air-Conditioning Engineers

ASME-American Society of Mechanical Engineers

ASTM-American Society for Testing and Materials

ATC-Automatic Temperature Control

ATM-Atmosphere

AUX-Auxiliary

B & S-Bell And Spigot

BBD-Boiler Blowdown

BDD-Back-Draft Damper

BG-Barrier Grill

BHP-Brake Horsepower

BOD-Bottom Of Duct

BOP- Bottom Of Pipe

BP-Back Pressure

BI-Backwards Inclined

BSMT-Basement

BTU-British Thermal Unit

BTUH-British Thermal Unit Per Hour

BU-Blower Unit

BV-Butterfly Valve

oC-Celsius

C-Condensate Line

C to C-Centre To Centre

CA-Compressed Air

CAP-Capacity

CAV-Constant Air Volume

CCU-Closed Control Unit

CDR-Condensate Drain Line

CF-Cubic Feet

CFH-Cubic Feet Per Hour

CFM-Cubic Feet Per Minute

CH-Chiller

CI-Cast Iron

CL-Centre Line

CO-Clean Out

COL-Column

CONN-Connection

CONT-Continuation

CR-Condenser Return

CS-Condenser Supply

CHWS-Chilled Water Supply

CHWR-Chilled Water Return

CV-Check Valve

CW-Cold Water

C/W-Complete With

CWR-Cold Water Riser

CU-Cubic/Cooling Unit

CT-Cooling Tower

CTBD-Cooling Tower Blow Down

D/DR-Drain

DBT-Dry Bulb Temperature

DDC-Direct Digital Control

DELTA T-Temperature Difference

DIA-Diameter

DIM-Dimension

DL-Door Louver

DP-Differential Pressure

DPT-Dew Point Temperature

DRV-Double Regulating Valve

DWG-Drawing

EA-Exhaust Air

EAD-Exhaust Air Duct

EAG-Exhaust Air Grill

EAHU-Exhaust Air Handling Unit

EAL-Exhaust Air Louver

EAR-Exhaust Air Register

EAT-Entering Air Temperature

EATR-Exhaust Air Transfer Ratio

ECG-Exhaust Ceiling Grill

ECD-Exhaust Ceiling Diffuser

EDH-Exhaust Duct Heater

EER-Energy Efficient Ratio

EF-Exhaust Fan

EG-Extract Grill

EJ-Expansion Joint

EL-Elevation

ELB-Elbow

ELSD-Exhaust Linear Slot Diffuser

ERV-Energy Recovery Ventilator

ESP-External Static Pressure

ET-Expansion Tank

EVAP-Evaporator

EVV-Exhaust Venture Valve

EXST-Existing

EXF-Exhaust Fan

EXT-External

E-FCU-Exposed Fan Coil Unit

F-Fahrenheit

FA-Free Area, Fire Alarm, From Above

FAF-Fresh Air Fan

FAHU-Fresh Air Handling Unit

FAI-Fresh Air Intake

FAL-Fresh Air Louver

FAD-Fresh Air Duct

FAF-Fresh Air Fan

FAR-Fresh Air Register

FB-From Below

FC-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

FJ-Flexible Joint

FLR-Floor

FM-Flow Meter

FPM-Feet Per Minute

FOV-Flush Out Valve

FRP-Fiberglass Reinforced Plastic

FS-Flow Switch

FTG-Fitting

FTR-Fin Tube Radiation

FU-Fixture Unit

FV-Flush Valve

GA-Gauge

GV-Globe Valve/Gate Valve

GPM-Gallons Per Minute

GR-Grade

HB-Hose Bib

HD-Head

HF-Hepa Filter

HP-Horsepower, High Point

HRU-Heat Recovery Unit

HRV-Heat Recovery Ventilator

HU-Humidistat

HVAC-Heating, Ventilating and Air Conditioning

HWS-Hot Water Supply

HWT-Hot Water Tank

ID-Inside Diameter

IV-Isolating Valve

J-Joule

K-Kelvin

KPA-Kilo Pascal

KW-Kilowatt

LAT-Leaving Air Temperature

LD-Linear Diffuser

LL-Low Level

LPD-Lift Pressurization Duct

LSD-Linear Slot Diffuser

LVR-Louver

LVL-Level

MAU-Makeup Air Unit

MU-Make-Up Water

MSD-Motorized Smoke Damper

MSFD-Motorized Smoke Fire Damper

MSIU-Mini Split Indoor Unit

NA-Not Applicable

NC-Noise Criteria, Normally Closed

NPHP-Name Plate Horsepower

NPS-Nominal Pipe Size

NPSH-Net Positive Suction Head

NRD-Non-Return Damper

NRV-Non Return Valve

NTS-Not To Scale

OA-Outside Air

OAT-Outside Air Temperature

OED-Open End Duct

OF-Overflow

PCR-Pounds Per Cubic Foot

PD-Pressure Drop

PICV-Pressure Independent Control Valve

PG-Pressure Gauge

PP-Primary Pump

PRD-Pressure Relief Damper

PRV-Pressure Reducing Valve

PSI-Pounds per Square Inch

PSIA-Pounds per Square Inch Absolute

PTAC-Packaged Terminal Air Conditioner

R/E-Return and Exhaust

RA-Return Air

RAD-Return Air Duct

RAG-Return Air Grill

RCD-Return Ceiling Diffuser

RD-Roof Drain

RH-Relative Humidity

RL-Refrigerant Liquid

RLA-Rated Load Amperes

RLBG-Return Linear Bar Grille

RLF-Relief

RLSD-Return Linear Slot Diffuser

RM-Room

RTU-Roof-Top Unit

RV-Relief Valve

SA-Supply Air

SAD-Supply Air Duct

SAG-Supply Air Grill

SAT-Supply Air Temperature, Sound Attenuator

SCD-Supply Ceiling Diffuser

SD-Smoke Detector, Smoke Damper

SE-Smoke Exhaust

SED-Smoke Extract Duct

SEG-Smoke Extract Grille

SEER-Seasonal Energy Efficiency Ratio

SF-Service Factor

SFD-Combination Smoke / Fire Damper

SHC-Sensible Heat Capacity

SI-International Systems of Units

SLBG-Supply Linear Bar Grille

SLSD-Supply Linear Slot Diffuser

SP-Secondary Pump

SPD-Stair Pressurization Duct

SS-Stainless Steel

SSH-Static Suction Head

SST-Saturated Suction Temperature

ST-Strainer

STH-Static Total Head

SVH-Static Velocity Head

T-Temperature, Thermostat

TA-To Above

TAB-Testing, Adjusting and Balancing

TB-To Below

TDH-Total Dynamic Head

TE-Toilet Exhaust

TED-Toilet Extract Duct

TEFC-Totally Enclosed Fan Cooled

TEWI-Total Equivalent Warming Impact

TON-12,000 Btuh

TSP-Total Static Pressure

TXV-Thermostatic Expansion Valve

UF-Under Floor

UH-Unit Heater

VAV-Variable Air Volume

VCD-Volume Control Damper

VD-Volume Damper

VFD-Variable Frequency Drive

VSD-Variable Speed Drive

VTR-Vent Through Roof

VVT-Variable Volume Variable Temperature

WB-Wet Bulb Temperature

WC-Water Column

WCO-Wall Clean Out

WG-Water Gauge

WH-Water Heater

ZV -Zone Valve

Next time you wonder what does hvac stand for, you’ll have the answer and more.


What do HVAC engineers do?

HVAC engineers are the ones responsible for the design, installation and maintenance of heating, ventilation, and air conditioning - HVAC systems.  As per client needs, an HVAC engineer will design and size a suitable system that fits the architectural model of an AEC project. This point on, an engineer may be involved in one or more of the following tasks:

  • Heat Load Analysis of a project

  • Preparation of conceptual model

  • Preparation of detailed design

  • Installation of HVAC system

  • Analysis of an installed system

  • Regular maintenance supervision of HVAC systems

  • Repair and fault analysis of existing systems

The actual nature of the job ultimately depends on whether you work for a consultancy (design), inspection agency(analysis), or an hvac contractor (construction).

What is hvac?

HVAC refers to the set of systems in a building responsible for the distribution of fresh and conditioned air.

Typical days as an engineer

1.      Consultancy

At a design firm, an HVAC engineer will be expected to come in and analyse architectural designs of buildings. Based on this analysis, you will have to carry out heat load calculations which are mostly computerized these days. Once this is done, you will design the layouts of the HVAC systems that are to go in the building with the help of drafting and modelling tools like AutoCAD, Revit, Creo, etc.

Additionally, you may be asked to carry out site visits and quality checks to ensure that construction takes place in accordance with design. Depending on the role you play in the organization, these activities may also involve having to deal with clients in order to understand their requirements and collaborating with fellow engineers and architects.

2.      Contractor

When working with a contracting company you will be responsible for ensuring proper installation of HVAC services in a project. You may be tasked with preparation of procurement schedules, preparation of inspection documents, preparation of testing documents, supervision of installation, commissioning, and maintenance activities, etc.

On site you will have to ensure necessary approvals for all drawings. You will have to inspect and confirm that all machines, ducts, pipes, accessories, etc. are available and approved before commencement of installation procedures. You will have to coordinate with other disciplines for installation of HVAC services without clashes. Site engineers will also be tasked with ensuring that personnel working under them are properly trained and in possession of the right equipment. You will also be a part of regular meetings with the management and quality assurance departments.  

3.      Inspection Agency

When working with an inspection agency, your primary task will involve the analysis of installation and construction activities on site. You will have to conduct assessments of materials, equipment, installations, and check whether they conform to approved design drawings, regulations and building codes. You will have to check if the contractor is following standards and safety procedures and report non-conformance if applicable.

Significance in the life-cycle of a building

An AEC project requires the coordinated efforts of a multitude of people from various disciplines. Architects, firefighting system designers, electrical engineers, structural engineers, and HVAC engineers work together with other consultants to achieve the desired result for the client. A well functioning HVAC system is critical in ensuring occupant comfort and health. Moreover, the HVAC system is also responsible for a major share of the building’s energy use. This necessitates the importance of proper design and installation of HVAC services.

Challenges

HVAC engineers, like anybody involved in the construction industry will be tasked with being a part of highly complex teams performing diverse processes. The nature of the profile will involve communication and coordination with other branches of the vine. Managements are ever under pressure to reduce costs owing to the highly competitive nature of the field and this trickles down to the engineers who have to ensure that savings do not come at the cost of quality or safety. System installation and maintenance also has to be handled with care as any downtime in the HVAC system will be dealt with severe criticism as no client will be polite or reasonable once their comfort is compromised. Another point to note is the presence of extreme climatic conditions at construction sites although how much this affects you will ultimately depend on your position in the firm. All of this coupled with strict deadlines can prove to be especially tricky.

Educational requirements

HVAC engineers are primarily from the mechanical discipline. A candidate looking towards a career in this industry will need to possess at least a bachelor’s degree in mechanical engineering. You can also choose to go for a master’s degree in HVAC. As you progress in your career, you can get certified in various sub-disciplines like energy modelling, energy assessment, high performance building design, healthcare facility design, and building operations. Industrial MEP courses are also available in the market which train novices in all hvac basics like hvac duct design, pipe design, estimation and other fundamental practices.

Other characteristics expected of a quality HVAC engineer are:

  • Communication skills

  • Mathematical ability

  • Logical reasoning

  • Problem solving skills

End word- As a career choice

A career in the HVAC industry can be a highly rewarding experience. The industry is to set to surge in productivity with breakthroughs in design and manufacturing technologies. Use of artificial intelligence algorithms in design, and automation in construction practices by hvac companies will open up fresh avenues for career choices. Employment options are well paid with plenty of scope for climbing up the corporate ladder. This is an industry where the fundamentals remain unchanged and ergo quality engineers with relevant experience are always in high demand. The same goes for technicians in the field as well. Skilled HVAC technicians consistently warrant the highest pay rates.

As living standards improve, a greater part of the world population will move to modern living quarters. This translates to increased demand for air conditioners and associated projects, which will ultimately lead to increased demand for novel structures and resourceful AEC projects.

Recent global average temperatures have soared at alarming rates decade over decade. The effects of climate change are starting to show with variations in weather patterns changing world over. In such a climate (pun intended) there will be a sharp increase in the need for efficient, cost-effective HVAC systems. Whether or not humanity is able to reverse global warming, hitching your career onto the HVAC wagon seems like nothing but a clever choice.