Common Terminology to Help You Better Understand Your AC Unit

The HVAC industry is full of different terminology and acronyms that the average Louisville homeowner isn’t familiar with. These unknown air conditioning terms sometimes makes shopping for a new cooling system or navigating repair needs difficult.

When you have a better understanding of common air conditioning terms, many homeowners feel more confident working with HVAC professionals and finding the right solutions for their homes. A knowledge of air conditioner terms helps you as you hunt for a new cooling system or figure out potential issues with your existing equipment with the help of a technician. Easy-to-understand definitions for air conditioning terms help you feel better informed and comfortable with your cooling system’s needs.

At Jarboe’s, we always want you to feel comfortable – providing a better understanding of our industry lingo is just as important as providing the products and services Louisville homeowners need for a cool summer home! Below, we define some common air conditioning terms with simple explanations to help you understand just what these important words and phrases mean.

When you need air conditioning installation, repair, or maintenance, call Jarboe’s! Our NATE-certified technicians are here to help. We always take the time to answer your questions and explain any air conditioning terms you aren’t familiar with – contact us today to have a chat about your cooling needs.

Air Conditioning Terms: Different Cooling Systems

The air conditioning terms below discuss the types of cooling systems available to Louisville homeowners:

  • Air Conditioner: This is sometimes used as a blanket term to cover all types of cooling systems and equipment, but an air conditioner actually refers to a specific type of cooling equipment. Most commonly, a residential air conditioner is part of a split system central air conditioner – what most people call the outdoor condensing unit. Air conditioners work by transferring heat from your home and releasing it outdoors to cool the indoor air.

  • Ductless Mini Split: This is a type of cooling system that does not use ducts like a traditional forced air cooling system. Instead, it has multiple air handlers that are located within desired areas of the home, connected to an outdoor heat pump or air conditioner.

  • Heat Pump: A heat pump cools a home using the same process as an air conditioner by transferring heat between your home and an outside source (the outdoor air for air-source heat pumps, the ground, or a water source for geothermal heat pumps). How it differs from an air conditioner is that it also provides heating.

  • Packaged Air Conditioners: A packaged air conditioner is not a split system because all components of the cooling system are housed together in a single unit. These systems are commonly used in commercial buildings (if you’ve seen an air conditioner on a roof of a store, this is likely a packaged unit), but they are available for residential use. Some packaged units also offer heating in addition to air conditioning.

  • Split System: Split systems are common in Louisville area homes. They consist of both indoor and outdoor components. Inside sits the evaporator coil and air movement equipment (an air handler or furnace), and outside sits the unit that holds the compressor and condenser coil. Central air split systems use ducts to circulate conditioned air into your living spaces.

Air Conditioning Terms: Cooling Components

These air conditioning terms cover components within Louisville cooling systems:

  • Air Handler: This indoor component holds a blower and is responsible for moving air conditioned by an air conditioner or heat pump into the home. Depending on the model you select, the air handler may contain auxiliary heat strips for heating your home.

  • Evaporator Coil: This indoor component is responsible for the first cooling step. Warm air moves across the surface of the evaporator coil and heat is absorbed by the refrigerant inside.

  • Condenser Coil: This outdoor unit conducts the last step of the cooling cycle. The condenser coil releases heat held by the refrigerant into the air outside of your home.

  • Compressor: The compressor is also an outdoor component. It is a pump that raises the pressure and temperature of the refrigerant after it leaves the evaporator coil before it moves to the condenser coil.

  • Condensate Drip Pan: The condensate drip pan sits below the evaporator coil to catch moisture extracted from the air during the cooling process. 

  • Condensate Drain: The condensate drain is connected to the drip pan. Water moves from the pan into the drain, which is a run of PVC piping that extends outside your home or to a floor drain. It carries moisture away to prevent damage to your home and cooling equipment.

  • Ducts: Central cooling systems use ducts to direct air from the cooling system into your living spaces and back again. These sheet metal or flexible tube components run through attics, basements, crawl spaces, and walls. Conditioned air moves into your living areas from the supply duct runs, and air returns back to the cooling system through the return duct runs.

  • Expansion Valve: The expansion valve lowers refrigerant pressure and temperature before it runs into the evaporator coil. Here refrigerant also converts back to a gas form from a liquid. The expansion valve also regulates refrigerant and voltage flow moving into the evaporator coil.

  • Filter: Filters are responsible for keeping cooling system components protected from airborne debris that build up and reduce performance. As they remove these contaminants for the protection of the system, they benefit Louisville homeowners with better indoor air quality as well.

  • Line Set: The line set refers to the refrigerant lines running between the indoor and outdoor cooling components. There is a small, uninsulated line that carries liquid refrigerant and a larger insulated suction line.

  • Plenum: The plenum is the section of ducting that connects the home’s return ductwork to the indoor cooling system components.

  • Refrigerant: Cooling systems contain refrigerant that absorbs and moves heat from the home to the outdoors. Older systems typically use R-22, also called Freon. R-22 Freon is being phased out of use, and environmentally friendly refrigerants like R-410a, also called Puron, are used in new cooling equipment.

  • Reversing Valve: This component is only present in heat pump systems. The reversing valve switches operation of a heat pump between heating and cooling modes. Since air conditioners do not heat a home, they do not have this component.

Air Conditioning Terms: Efficiency and Capacity

Learn how cooling system capacity and efficiency are measured with these air conditioning terms:

  • British Thermal Unit (BTU): A cooling system’s ability to pull heat from space is reflected in BTUs. It’s a heat equivalent measure of the amount of energy needed to increase temperature in a pound of water one degree Fahrenheit.

  • British Thermal Units per Hour (BTU/H): Btu/h is how many BTUs of heat an air conditioning unit is able to pull from a home over the course of one hour.

  • Capacity: A measure reflected in tons (tons of cooling, not weight), capacity shows the air conditioner’s ability to remove heat.

  • Energy Efficiency Ratio (EER): EER shows the efficiency of heat pumps and window air conditioners. It’s a consistent measure rather than a seasonal one. Btu/h divided by watt energy input equals a unit’s EER.

  • Minimum Efficiency Reporting Value (MERV): This is a measure of a filter’s effectiveness; it describes both the size of particles the filter is capable of removing as well as its efficiency in doing so. MERV goes from 1 to 16 for residential HVAC systems – MERV 1 filters are low efficiency; MERV 16 filters are high efficiency.

  • Seasonal Energy Efficiency Ratio (SEER): SEER reflects an air conditioner or heat pump’s cooling efficiency over a typical cooling season. For a set period of time, total cooling output is divided by total energy input. In Kentucky, newly installed air conditioners must be a minimum of 14 SEER; in Indiana, the minimum is 13 SEER.

  • Tons of Cooling: A measure of an air conditioner’s capacity. One ton of cooling is equal to 12,000 BTU/H.

Air Conditioning Terms: Other Terminology

Here are some additional air conditioning terms you may hear when speaking with a technician:

  • Air Balance: For an HVAC system to perform optimally and efficiently, all components must receive proper airflow. A balanced cooling system is when all components receive the airflow they need at any given time.

  • Air Changes per Hour: This measure reflects how many times in one hour your home’s total air volume indoors is replaced through air conditioning or natural ventilation.

  • Charge the System: Charging the system means adding refrigerant, which can be necessary after the repair of a refrigerant leak. Gauges are used to measure refrigerant pressure, which shows if more refrigerant needs to be added.

  • Cooling Load: Cooling load is the rate all heat needs to be removed from your home to maintain the temperatures you want. This calculation is performed by a technician using the Manual J method.

Talk Air Conditioning Terms with Jarboe’s Today!

After you’ve read through our explanation of air conditioning terms, call Jarboe’s for help with air conditioner installation, repair, and maintenance! Our NATE-certified techs give you a thorough explanation of our recommendations, make sure you understand our air conditioning terms and help you find the best comfort solutions for your Louisville home.

Contact Jarboe’s today for quality air conditioning service in Louisville!

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