• The HVAC industry can be a labyrinth of unfamiliar terminology and strange acronyms. When buying a new HVAC system, you may feel like you’re in over your head even before you get started. Don’t get overwhelmed. Familiarize yourself with the basics even if you are a true HVAC novice. In fact, let’s start with HVAC. What is HVAC?

    HVAC is an abbreviated term for Heating, Ventilation, and Air Conditioning. The goal in HVAC design is to balance indoor environmental comfort with other factors such as installation costs, ease of maintenance, and energy efficiency. As the discipline of HVAC includes a large number of specialized terms and acronyms, here are some frequently used terms that will help you navigate the process of selecting the best HVAC solution for you.


AHU (air handling unit)

A central unit consisting of a blower, heating and cooling elements, filter racks or chamber, dampers, humidifier, and other central equipment in direct contact with the airflow.

AWHP (Air to Water Heat Pump)

A system that allows space heating, floor heating, cooling and hot water supply. Not only can you install it in your new home, but you can also replace boilers in your existing home.

British thermal unit (BTU)

A British Thermal Unit is a measurement of the amount of heat required to raise or lower the temperature of one pound of water one degree Fahrenheit.

CFD (Computational Fluid Dynamics)

An integral tool for determining the optimal performance of the system. With the LG CFD Analysis report, engineers are able to determine whether product can perform properly under specific conditions.


A device that removes heat from a liquid via a vapor-compression or absorption refrigeration cycle. This cooled liquid flows through pipes in a building and passes through coils in air handlers, fan-coil units, or other systems, cooling and dehumidifying air in the building.


A refrigeration component that makes a pressure difference in the system which causes refrigerant to flow.


A component in the basic refrigeration cycle that ejects or removes heat from the system. The condenser is the hot side of an air conditioner or heat pump.


A plate or gate placed in a duct to control air flow by increasing friction in the duct.

DOAS (dedicated outdoor air system)

A system that brings fresh outdoor air indoors to improve air quality without sacrificing energy efficiency.


Specialized pipes or channels for the airflow (including supply air, return air and exhaust air) within a home.

ERV (Energy recovery ventilator)

Highly efficient ventilation solution for fresh indoor air.

Fan Coil

An indoor component of a heat pump system used in place of a furnace, to provide additional heating on cold days when the heat pump does not provide adequate heating.

GAS Heat Pump (GHP)

A kind of VRF driven by gas engine, it is suitable for any buildings using gas conveniently as energy source or better heating needed. It provides High efficiency operation and heat recovery.

Heating coil

A heating coil is the part of the system that conducts heat. It allows electricity to act as fire.

Heat exchanger

A heat exchanger is the part of the system that transfers heat from the hot parts of the machine or a system to the cold parts of the machine or system.

Heat pump

A heat pump is a compressor that cycles hot or cold air. It is a device that is designed to move thermal energy in the opposite direction of heat flow by absorbing heat from a cold space which is released to a warmer space.


An electronic device that converts fixed voltage to variable frequency and voltage. Enables the user to electrically vary the speed of an AC motor.

LATS (LG Air Conditioner Technical Solutions)

LG’s design software for integrated technical solutions which features tools to reduce drawing and design time.

MV (LG Monitoring View)

LG Monitoring View (LGMV) is a maintenance and troubleshooting tool for Multi V™ air conditioning systems. After a quick install of the LGMV Wi-Fi Module, technicians can review diagnostic information and graph data values to help troubleshoot any issue with ease. Real-time values are available for the outdoor and indoor units and can be graphed to evaluate operating trends.


The study of the behavior of air-water vapor mixtures. Water vapor plays an important role in energy transfer and human comfort in HVAC design.

R32 Refrigerant

An environmentally friendly refrigerant which has a low Global Warming Potential (GWP) of 675. It provides powerful and highly efficient heating.

R410A Refrigerant

A hydrofluorocarbon (HFCs) refrigerant, recognized as safer than R22 with an ODP (Ozone Depletion Rate) of 0 and a GWP (Global Warming Potential) of 2,090.


The compound (working fluid) used in air conditioners, heat pumps, and refrigerators to transfer heat into or out of an interior space. This fluid boils at a very low temperature enabling it to evaporate and absorb heat.


A unit providing heating or cooling to an area by treating the air that passes through it and then circulating that air.

Split system

A split system is the combination of an outdoor unit and an indoor unit. This is the most common type of system and there's a variation of single CAC and multi-type.


A thermostat is a system that monitors and regulates a heating or cooling system. It can be used to set the desired temperature at which it keeps the environment either heated or cooled.

Two-stage (cooling and heating)

A two-stage air conditioner is designed to operate on high and low settings during different weather conditions and seasons. The high setting is used during extreme weather, and the low setting is used during moderate weather. This type of air conditioner produces a balanced temperature and is in use for a longer period of time.


A component of a heating or ventilation appliance used to conduct fresh air into, or waste air or combustion gases out of, an appliance or interior space.

VRF (Variable Refrigerant Flow)

A system that uses refrigerant as the cooling and heating medium. This refrigerant is conditioned by a single or multiple condensing units (which may be outdoors or indoors, water or air cooled), and is circulated within the building to multiple indoor units.
  • *Source:
    1. HVAC Abbreviations Directory. (n.d.). ISHRAE. Retrieved June 15, 2021, from https://ishrae.in/Abbreviations
    2. Wikipedia contributors. (2021, June 10). Glossary of HVAC terms. Wikipedia. https://en.wikipedia.org/wiki/Glossary_of_HVAC_terms

*Products and solutions may vary according to country and operating conditions.
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