Common Air Conditioning Acronyms and Terms

And just like that we’re greeted with cool fall-worthy weather. You never know what to expect in Austin air conditioning-wise. It may be time to let up a bit on the thermostat setting, at least for now, but that doesn’t mean it’s time to stop thinking about it all together. For one thing, this being Austin, there’s a good chance we’ll get more hot weather before things go full autumn. And secondly, this being the end of summer, it’s an excellent time to get some maintenance done on your air conditioning system to make sure it survived the hot summer without any significant wear. And it’s a good time to make sure your heating system is up to par in preparation for the winter. Either way, for long-lasting quality Austin air conditioning, the fall and spring seasons both make wonderful times to get your HVAC system checked out.

HVAC stands for Heating, ventilation, and air conditioning, in case you didn’t know. Maybe you did, but either way, there are a lot of acronyms thrown around out there when talking about air conditioning. Knowledge is power, and when it comes to air conditioning specifically, knowing what websites and contractors, manufacturers and manuals are talking about when they use terms and acronyms specific to the industry can give you big leg up when it comes to getting the best deal and the best products. That’s why this tip will be dedicated to delving into the world of HVAC and what many of the most commonly used acronyms and terms in it are.

Important Terms to Know

The following are some common terms you might hear used when researching or talking about air conditioning and heating systems. Most of these you’ll hear without them being shortened into acronyms most of the time.

Air Conditioner - An appliance, system, or mechanism designed to control temperature, humidity and air quality in a defined space.

Air Handler 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. This does not include the ductwork through the building.

Ambient - Normal atmospheric conditions of temperature & pressure. In other words, the ambient temperature is the temperature surrounding a unit under normal conditions.

Blend - A refrigerant mixture of two or more refrigerants blended in a specific ratio which can be separated by distillation. Regular blends may have up to 10°C or more temperature glide.

Centrifugal – Refers to a component that works on the concept of centrifugal pressure, pressure from spinning. A centrifugal fan is a mechanical device for moving air or other gases. A centrifugal compressor is a compressor with a rotating wheel which pushes the refrigerant outwards towards the rim of the wheel and from there to the condenser. It compresses gas using centrifugal force.

Change of State – Refers to when something changes from a solid, gas, or liquid, to one of the other states of matter.

Compressor - A key component of the refrigeration system, raising the pressure (and hence temperature) of the refrigerant and circulating it through a closed loop system.

Condenser - 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. Condensers are heat exchangers, and can transfer heat to air or to an intermediate fluid to carry heat to a distant sink, such as the ground, a body of water, or air.

Controller - A device that controls the operation of part or all of a system. It may simply turn a device on and off, or it may more subtly modulate the set point of components. Most controllers are automatic but have user input such as temperature set points. Controllers can be both analog and digital.

Damper - A modulating device for controlling airflow rates through ductwork or air handling equipment.

Dehumidifier - A dehumidifier is the equipment that extracts and removes humidity from the air. It works by cooling air to the point where water turns to liquid from vapor form and then the liquid is removed.

Ducts – Constructions used in heating, ventilation, and air conditioning (HVAC) to deliver and remove air including supply air, return air, and exhaust air.

Evaporator - A component in the basic refrigeration cycle that absorbs or adds heat to the system. Evaporators can be used to absorb heat from air or from a liquid. The evaporator is the cold side of an air conditioner or heat pump.

Flow - A transfer of fluid volume per unit time.

Furnace - A component of an HVAC system that adds heat to air or an intermediate fluid by burning fuel (natural gas, oil, propane, butane, or other flammable substances) in a heat exchanger.

Gauge Pressure - The reading taken from a gauge normally zeroed at atmospheric pressure, which is one bar absolute or 14.7 psi, so that pressures can be also be read as a negative when below atmospheric pressure.

Grille - A facing across a duct opening, often rectangular in shape, containing multiple parallel slots through which air may be delivered or withdrawn from a ventilated space. The grille directs the airflow in a particular direction and larger things from coming into the duct.

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.

Inverter Compressor - This type of compressor uses an inverter drive to control the compressor motor speed to modulate capacity as demand varies.

Packaged Unit - A self-contained air handling unit made specifically for outdoor installation; it includes all heating and cooling devices pre-assembled prior to installation.

Refrigerant - The fluid used for the heat transfer within a refrigeration system. The refrigerant absorbs heat at low temperature and pressure and transfers heat at high temperature and pressure. The refrigerant comes in many different types, commonly fluorocarbon compounds, but also natural refrigerants such as ammonia, CO2, hydrocarbons as well as other compounds such as water and air.

Radiation - The transfer of heat directly from one surface to another (without heating the air acting as a transfer mechanism).

Radiant Flooring - A type of radiant heating system where the building floor contains channels or tubes through which hot fluids such as air or water are circulated. The whole floor is evenly heated. Thus, the room is heated from the bottom up. Radiant floor heating eliminates the draft and dust problems associated with forced air heating systems.

Split System - A split system is the combination of an outdoor unit and an indoor unit. This is the most common type of HVAC system.

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

Two-Stage - 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.

Watt – Used when talking about power. The watt is a derived unit of power in the International System of Units, named after the Scottish engineer James Watt. The unit is defined as joule per second and can be used to express the rate of energy conversion or transfer with respect to time.

Zoning System - A zoning system sections a building or a space into zones which are controlled independently of each other. This is beneficial when different areas or rooms of a building have different temperatures as well as when the desired temperatures in different rooms are different. Temperature is controlled by different thermostats.

Common Acronyms and Definitions

AC – Stands for either air conditioning, air conditioner, or alternating current. When talking about electricity or power, alternating current is the name for the most common type of current used in power, as opposed to DC, direct current.

ACH – Stands for air changes per hour. It is the hourly ventilation rate divided by the volume of a space. For perfectly mixed air or laminar flow spaces, this is equal to the number of times per hour that the volume the space is exchanged by mechanical and natural ventilation

AFD – Stands for adjustable frequency drive. This is a type of drive used in invertor systems which can change the motor speed of an air conditioner fan.

ASHRAE – Stands for American Society of Heating Refrigeration and Air Conditioning Engineers.

BTU – Stands for British Thermal Unit. It’s the imperial measurement for the quantity of heat required to be given to or taken from 1lb. of water in raising or lowering its temperature by 1°F.

EER – Stands for Energy Efficiency Ratio. Energy Efficiency Ratio is a measure of system efficiency at a given set of rating conditions. It is a ratio calculated by dividing the cooling capacity in kW by the power input in kW.

IAT – Stands for inside air temperature.

HSPF – Stands for Heating Seasonal Performance Factor. Heating Seasonal Performance Factor is the measurement of heat efficiency over the period of a heating season.

HVAC – Stands for heating, ventilation, and air conditioner. Used often when referring to whole systems of air handling and air treating within homes.

NATE – Stands for North American Technical Excellence. This is a program for the certification of technicians. NATE certified technicians have proven their capability for superior installation and maintenance or service of heating, ventilation, air conditioning or refrigeration systems.

OAT – Stands for outside air temperature.

SEER – Stands for Seasonal Energy Efficiency Ratio. The SEER rating of a unit is the cooling output during a typical cooling-season divided by the total electric energy input during the same period. The higher the unit's SEER rating the more energy efficient it is.

HVAC and Air Conditioning Repair in Austin

As you can see, in some ways, the realm of air conditioning and heating has a language all of its own. Knowing is half the battle, which, in this case, is the battle of finding the best deal out of the multitude of options available to you. You want to be able to know what you’re getting, what you’re looking for, and what you’re talking about when you’re looking to upgrade, repair, or replace your HVAC system.

If you are in need for AC repair in Austin, there’s no better place to turn to than AC Express. AC Express is an Austin AC repair company that has been operating for many years on the HVAC systems of people in Georgetown, Lakeway, Taylor, Manor, and many other suburbs of and around Austin. For A/C repair in Austin that can’t be beat, go no further than AC Express. Call today!