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Smalley's Air Conditioning & Heating, Inc. wants customers to understand the HVAC service we are providing and why. That's why our team in Baytown, Texas, has compiled a list of common HVAC terms and jargon along with definitions for each.

Glossary of Terms

Annual Fuel Utilization Efficiency (AFUE) - A measure of a gas furnace efficiency in converting fuel to energy. The higher the rating, the more efficient the unit.

British Thermal Unit (BTU) - This is the amount of heat it takes to raise one pound of water one degree Fahrenheit. For your home, it represents the measure of heat given off when fuel is burned for heating, or the measure of heat extracted from your home for cooling.

Cubic Feet per Minute (CFM) - A standard measurement of airflow. A typical system requires 400 CFM per ton of air conditioning.

Capacity - The output or producing ability of a piece of cooling or heating equipment. Cooling and heating capacities are referred to in BTUs.

Comfort-R™ Airflow System - An exclusive feature of home comfort systems from American Standard. This method of ramping airflow gives you greater humidity control in cooling, and provides warmer air during heating startup.

Compressor - The heart of an air conditioning or heat pump system, it is part of the outdoor unit and pumps refrigerant in order to meet the cooling requirements of the system.

Condenser Coil or Outdoor Coil - In an air conditioner, the coil dissipates heat from the refrigerant, changing the refrigerant from vapor to liquid. In a heat pump system, it absorbs heat from the outdoors.

Damper - Found in ductwork, this movable plate opens and closes to control airflow in a duct system. They are also used in zoning to regulate airflow to certain rooms.

Ductwork - Pipes or channels that carry air throughout your home. In a home comfort system, ductwork is critical to performance. In fact, it's as critical as the equipment.

Evaporator Coil or Indoor Coil - The other half of your air conditioning system located inside your home in the indoor unit. This is where the refrigerant evaporates as it absorbs heat from the air that passes over the coil.

Gas Furnace Heat Exchanger - Located in the furnace, the heat exchanger transfers heat to the surrounding air, which is then pumped throughout your home.

Heating Seasonal Performance Factor (HSPF) - This rating is used in measuring the heating efficiency of a heat pump. The higher the number, the more efficient the unit.

Refrigerant - A chemical that produces a refrigerating effect while expanding and vaporizing. Most residential air conditioning systems contain R-22 refrigerant. It's used in approximately 95 percent of air conditioning equipment manufactured in the U.S. today.

Seasonal Energy Efficiency Ratio (SEER) - A measure of cooling efficiency for air conditioners and heat pumps. The higher the SEER, the more efficient the unit is. The government's minimum SEER rating is 10.

Split System - The combination of an outdoor unit (air conditioner or heat pump) with an indoor unit (furnace or air handler). Split systems must be matched for optimum efficiency.

Ton - A unit of measurement used for determining cooling capacity. One ton is the equivalent of 12,000 BTUs per hour.

Package Unit - A heating and cooling system contained in one outdoor unit. A package unit is typically installed either beside or on top of the home, or sometimes in the attic.

Seasonal Extreme Environmental Test Lab (SEET) - This is American Standard's torture chamber for heating and air conditioning systems, where five years of service are condensed into 16 weeks. If a product doesn't make it through the SEET lab, it's not manufactured.

Zoning - A method of dividing a home into different comfort zones so each zone can be independently controlled depending on use and need.