AHU Air handling unit:   A central unit consisting of fan(s), heating and cooling elements, filter racks or chamber, dampers, humidifier, and other central equipment required to provide suitable ventilation and extract.


BTU Heating Max: Maximum heating output of a heat pump is always more than its potential cooling output. Because the unit is rated based on its cooling output you will almost always see the max heating higher than the rated size of a system.


Compressor : A key component of the refrigeration system, raising the pressure (and hence temperature) of the refrigerant and circulating it through a closed loop system.


Condenser:  A vessel or an air cooled coil that removes the superheat of compression, condensing the refrigerant gas into a high pressure liquid.


Heat pump:  A heat pump is a mechanical device that absorbs low grade heat from a lower temperature location and upgrades and transfers the resultant higher temperature medium, created by mechanical work, to heat a space to a sufficient comfort level. Heat pumps may be air to air, air to water, water to water or ground to water.


HSPF (Heating Seasonal Performance Factor):  HSPF is the measurement used to gauge the heating efficiency of heat pumps. The higher the HSPF number, the greater the efficiency and cost-savings. HSPF is calculated by taking the total annual heating requirements, divided by the total electric power used. Today’s models of heat pumps are required to have a minimum 7.7 HSPF. The most efficient heat pumps have an HSPF of over 10.


MUA Make Up Air Unit:  Intake supply fan to replace air exhausted from a building. MUA may be heated or cooled so that the air coming in does not have a major impact on the building air conditioning systems, but is not designed to cool or heat the building.


Microprocessor:  The microprocessor is an electronic component that consists of integrated circuits. In an air conditioner, the microprocessor uses computerized technology to monitor and control the unit's performance.


Refrigerant:  The fluid used for the heat transfer within a refrigeration system. The refrigerant absorbs heat at low temperature and pressure and transfers heat at high temperature and pressure. The refrigerant can be many materials, commonly fluorocarbon compounds, but also natural refrigerants such as ammonia, CO2, hydrocarbons as well as other compounds such as water and air.


SEER: Similar to the HSPF rating the Seasonal Energy Efficiency Ratio:  Measures the average cost to run a unit for both heating and cooling. A ductless heat pump with a larger SEER rating will cost less money to run than one with a lower SEER rating, assuming your producing the same amount of heat or cold.

Split-Ductless System:  A split-ductless system contains both an outdoor and indoor unit. They are connected by refrigerant pipes, but there is usually no ductwork. However, limited ductwork can be installed for ventilation.

Split-Ducted System:  A split-ducted system has an indoor and an outdoor unit. The units are connected by refrigerant pipes, and the system uses ducts to carry the air.

Split-Zoning System:  A split-zoning system consists of an indoor and outdoor unit, and they are connected by refrigerant pipes. The system is designed to heat and cool specific zones inside the building, which allows for superior climate control. All of the zones are independent from each other.

 Zone:  A zone is made up of one or more rooms in the same building, and each zone has its own temperature setting. All zones are independent from each other.