What Does That Mean?

A glossary of AC terms you should know

The professionals at Custom Climate Concepts understand that the HVAC world is filled with industry terms and acronyms that aren’t readily known. But it wasn’t until we saw this meme in a social media post that we realized a HVAC glossary could be an asset for our customers.

When the A.C. Repair man is trying to tell you what's wrong with your air conditioner and he may as well be speaking Greek!!

That’s why we have compiled some of the basic and important words and phrases, and their meaning,  to help you ‘get it’ if your HVAC develops a hiccup.

Of course, there is more HVAC language than it is possible to fully cover, so please don’t hesitate to ask us to explain anything we say or describe about your AC system, at any time. You can reach us at 941-955-COOL (2665).

  • AC (Alternating Current):  A type of current where the polarity is perpetually reversing, causing the directional flow in a circuit to reverse at regular intervals.
  • Air Conditioner:  A device that changes humidity levels, temperature or quality of air.
  • Air Handler:  Indoor part of the air conditioning system including the circulating fan and evaporator (summer) / condenser (winter) coil.
  • 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.
  • Capacity:  HVAC capacity is the output produced by the heating or cooling unit and is measured in BTUs per hour.
  • Charging a System:  Adding coolant, or refrigerant, to an HVAC system.
  • Coil: The coil, or evaporator coil, is connected to the airflow outlet of the furnace. Conditioned refrigerant is circulated through the coil to cool the structure in the summer and heat in the winter. As warm indoor air passes through the indoor or evaporator coil, temperature and humidity are removed creating cooler indoor air. Installing a correctly sized and rated evaporator coil is essential for getting the highest performance and comfort from your central air conditioning or heat pump system.
  • Compressor:  A pump that increases the pressure of refrigerant gas.
  • Ductwork:  A network of metal, fiberboard or flexible material flowing throughout a space which delivers air from an HVAC unit to the respective zones of a home or office.
  • Evaporator Coil:  Also an indoor coil. A device that is designed to absorb heat in the air in order to change the liquid refrigerant that flows through it into a vapor initiating the cooling process.
  • Filter:  A central heating and cooling system may use multiple filters. The air filter is integral to the system intake ducting, prevents contaminants from entering the equipment and must be maintained or replaced at regular intervals. There is also a filter in the refrigeration system, also referred to as a drier, which acts like a strainer to remove dirt and undesired particles from the system.
  • Manufacturer Approved System:  If replacing a condensing unit, furnace or air handler, the system must be manufacturer approved and Air Conditioning, Heating and Refrigeration Institute (AHRI) matched. NOTE: Installation of unmatched systems is strongly discouraged.
  • NATE:  North American Technician Excellence is the nation’s largest non-profit certification organization for heating, ventilation, air conditioning and refrigeration technicians. NATE is the only technician certification organization governed, owned, operated, developed and supported by the HVACR industry. NATE’s website can be found at www.natex.org.
  • Programmable Thermostat:  A type of thermostat that allows the user to program into the devices’ memory a pre-set schedule of times and temperatures enabling or disabling the HVAC equipment.
  • Refrigerant:  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 exude and absorb heat.
  • Refrigerant Charge:  The amount of refrigerant in a system.
  • SEER:  The efficiency of air conditioners is often rated by the Seasonal Energy Efficiency Ratio, which is defined by the Air Conditioning, Heating, and Refrigeration Institute as the cooling output during a typical cooling-season divided by the total electric energy input during the same period.
  • Split System:  An outdoor unit combined with an indoor unit (as opposed to a package unit), generally providing more efficiency and configuration options.
  • Ton:  One ton is 12,000 BTUs per hour.
  • Zoning:  A system that divides a home, office or space into different regions in order to better control the temperature and effectiveness of a heating and cooling system.

Sources: amana-hac.com, ashrae.org, think-energy.net