HVAC 101

Air Handler

The indoor cabinet that holds the blower and usually the evaporator coil, moving cooled air through your home.

Airflow

The movement of air through your AC equipment, ductwork, and rooms, and the single biggest factor in how well a system actually cools.

Auto Fan

The thermostat fan setting that runs the blower only while the system is actively cooling, which is the right choice for almost every Florida home.

Blower Motor

The indoor motor that pushes air across the cold coil and through your ducts to every room in the house.

Breaker

The electrical safety switch in your panel that cuts power to the AC when something draws more current than is safe.

Capacitor

A small electrical component that gives your AC's motors the jolt they need to start and the steady push they need to keep running.

Compressor

The heart of your AC: the pump in the outdoor unit that pushes refrigerant through the system so heat can be carried out of your home.

Condensate

The water your AC pulls out of humid indoor air, which has to drain safely away every day the system runs.

Condenser Coil

The grid of metal fins wrapped around your outdoor unit that releases the heat collected from inside your home.

Contactor

The heavy-duty electrical switch in the outdoor unit that connects power to the compressor and fan when your thermostat calls for cooling.

Cycle

One complete run of your AC from the moment it starts until the thermostat is satisfied and it shuts off.

Drain Line

The pipe that carries the water your AC collects out of the house, and the number one cause of AC water leaks when it clogs.

Drain Pan

The pan under your indoor coil that catches the water your AC pulls from the air so it can drain away instead of into your ceiling.

Dry Mode

A setting on some systems that prioritizes pulling moisture out of the air over dropping the temperature.

Ductwork

The network of pathways that carries cooled air to your rooms and pulls house air back to the system to be conditioned again.

Evaporator Coil

The cold indoor coil that absorbs heat and moisture from your home's air as the blower pushes air across it.

Float Switch

A small safety device that shuts your AC off before a clogged drain line can overflow into your home.

Heat Pump

An air conditioner that can run its cooling cycle in either direction, moving heat out of your home in summer and into it on rare cool nights.

Humidity

The moisture in your air. In South Florida, controlling it is half of what your air conditioner is really for.

HVAC

The industry shorthand for heating, ventilation, and air conditioning: everything that controls the temperature, humidity, and freshness of the air in your home.

Indoor Unit

The inside half of your AC system: the cabinet with the blower and cold coil that conditions your air and sends it through the ducts.

Line Set

The pair of insulated copper lines that carry refrigerant between your indoor and outdoor units.

Low-Voltage Wiring

The thin control wires that let your thermostat tell the rest of the AC system what to do.

Mini-Split

A ductless system that pairs an outdoor unit with one or more wall-mounted indoor heads, cooling individual rooms without any ductwork.

Outdoor Unit

The cabinet outside your home that houses the compressor, condenser coil, and fan, and does the heavy work of rejecting heat outdoors.

Package Unit

An all-in-one system with the compressor, coils, and blower in a single outdoor cabinet, connected to your home only by ductwork.

Pressure Drop

The resistance air meets as it squeezes through a filter, coil, or duct, and a number that quietly decides how hard your blower has to work.

Refrigerant

The working fluid that carries heat out of your home by changing between liquid and vapor as it cycles through the system.

Return Air

The house air your system pulls back in through the big grille so it can be filtered, cooled, and sent out again.

Run Time

How long your system runs during each cooling cycle, and one of the most telling clues about system health and sizing.

SEER2

The current efficiency rating for cooling equipment: the higher the number, the less electricity the system uses to deliver the same comfort.

Short Cycling

A pattern where the AC starts and stops too frequently instead of running long, steady cycles, wearing out parts and leaving the air humid.

Split System

The most common AC setup: an outdoor unit and an indoor unit working as a pair, connected by refrigerant lines.

Static Pressure

The total resistance your blower pushes against to move air through the system, and the blood pressure reading of your ductwork.

Supply Vent

The grilles and registers where cooled air enters your rooms after its trip through the ductwork.

Temperature Split

The difference between the air entering your system and the air leaving it, and the quickest single health check an AC can get.

Thermostat

The control on your wall that reads the room and tells the rest of the system when to cool.

Ton

The unit of cooling capacity for AC equipment. It measures how much heat a system can move, not how much it weighs.

Variable Speed

Equipment that can ramp its output up and down smoothly instead of only switching between full blast and off.

Zoning

A system design that divides your home into independently controlled comfort areas, each with its own thermostat.