HVAC Terms
Plain English.

MERV stands for Minimum Efficiency Reporting Value. It rates how effectively an air filter captures particles like dust, pollen, pet dander, and mold spores. MERV ratings run from 1 to 16. Higher MERV means better filtration — but also more airflow restriction. For most Florida homes, a MERV 8-11 filter is the sweet spot between air quality and system performance.

Static pressure measures the resistance to airflow in your duct system. Think of it like blood pressure for your AC — too high and your system has to work harder to push air through, reducing efficiency and lifespan. High static pressure is often caused by undersized ducts, too many bends, or a dirty air filter.

The evaporator coil sits inside your air handler and is where warm air from your home passes over cold refrigerant, removing heat and humidity. It's one of the most important components in your AC system. A dirty or frozen evaporator coil will significantly reduce cooling performance and can cause your system to stop working entirely.

The air handler is the indoor component of your AC system that circulates conditioned air throughout your home. It contains the blower motor, evaporator coil, and air filter. The air handler works together with the outdoor condenser unit to cool and dehumidify your home. In Florida, air handlers are typically located in a closet, attic, or garage.

The compressor is the heart of your AC system — it pressurizes the refrigerant and circulates it through the system. It sits in the outdoor unit and is the most expensive single component in your AC. A failed compressor often means a failed system. Compressors typically last 10-15 years with proper maintenance.

Short cycling is when your AC turns on and off repeatedly in short bursts instead of running full cooling cycles. A properly functioning AC should run for 15-20 minutes at a time. Short cycling puts excessive wear on your compressor, increases energy bills, and means your home never fully cools down or dehumidifies properly.

A heat pump is an all-in-one heating and cooling system that moves heat rather than generating it. In summer it works like a standard AC, pulling heat out of your home. In winter it reverses and pulls heat from outside air into your home. In Florida's mild winters, heat pumps are highly efficient and very common.

Refrigerant is the chemical that circulates through your AC system and transfers heat from inside your home to the outside. The most common types are R-22 (Freon, now phased out) and R-410A. Low refrigerant usually means there's a leak — refrigerant doesn't just "run out" on its own.

A capacitor is a small cylindrical component that stores and releases electrical energy to start and run your AC's motors. There are two types — start capacitors and run capacitors. When a capacitor fails, your AC unit may struggle to start, make a humming noise, or stop working entirely.

SEER stands for Seasonal Energy Efficiency Ratio. It measures how efficiently your air conditioner uses electricity over a cooling season. The higher the SEER rating, the more efficient the unit. In Florida, a minimum SEER of 15 is required for new installations. Most modern units range from 15 to 25 SEER.