Zoneline Buying Tips

Common Air Conditioner Terminology

AHAM (Association of Home Appliance Manufacturers)

AHAM administers a room air conditioner certification program that assures that all name plate information (cooling and heating capacities, amperes, energy efficiency rating) is accurate. Participation is voluntary. All GE window and built-in air conditioning products are certified by A.H.A.M.

AHRI (Air Conditioning, Heating and Refrigeration Institute)

A voluntary, non-profit organization comprised of the manufacturers of air conditioning, heating and refrigeration products. AHRI develops performance rating standards and administers performance certification programs for the eligible products. GE Zoneline products are AHRI certified.

Air Change

The quantity of infiltration or ventilation air in cubic feet per hour divided by the volume of the room. An air change of 1 means that the room under consideration had a complete air exchange with the outdoors in one hour.

Air Conditioning

The process of treating air so as to control simultaneously its temperature, humidity, cleanliness, and distribution to meet the requirements of the conditioned space.


Current carrying capacity of electrical conductors expressed in amperes.

Ampere (Amp)

Unit of measure for the rate of flow of electrical energy. Amps are often referred to as current.

BTU (British Thermal Units)

The amount of heat to be added or removed in order to raise or lower the temperature of a pound of water by one degree Fahrenheit. It is approximately equivalent to the heat given off by the burning of one old-fashioned wooden kitchen match.

BTUH (British Thermal Units per Hour)

The number of BTU’s required to raise or lower the temperature of a given substance or space a calculated number of degrees and maintain that temperature for one hour. This is what you find from a “heat loss” or “heat gain” calculation. This is a must to determine the equipment capacity required by the air conditioner.

Balance Point

Occurs when the heat loss of a conditioned space equals the maximum heat supplied by the heat pump. For instance, if at 25° F outdoor temperature the heat pump were producing just enough heat to replace the heat loss from the conditioned space, the balance point would be 25° F.

CFM (Cubic Feet per Minute)

The term used to indicate air quantity.

Cop (Coefficient of Performance)

The coefficient of performance (COP) of a Heat Pump is the measurement of output energy of heat for a given input energy supplied to the Zoneline at a given outdoor temperature. The higher the COP, the more heat can be delivered by the Zoneline for a given input. As an example, a COP of 3.2 says that the Zoneline will deliver 3.2 units of energy for one unit of energy inputted. The COP changes with the O.D. temperature, decreasing with a drop in outdoor temperature. An electric resistance heater has COP of one and is unaffected by outdoor temperatures.

Central System

A mechanical indirect system of heating, cooling or ventilating in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and is conveyed to and from the rooms by means of a fan or blower and a system of distributing ducts.

Circuit breaker

A protective device designed to open a circuit (stop the flow electricity) when that circuit is overloaded without damage to the circuit breaker. After automatic actuating, it is reset manually. It is also used manually to open a circuit when doing electrical work on the circuit.


The creation of a condition within a defined area or space that produces a feeling of contentment. In other words, where the occupant is not aware of either heat or cold or air movement.


The moisture removed from indoor air at the indoor coil of the cooling unit. This results when the surface temperature of the coil is lower than the dew point temperature of the air passing through the coil. Simply related, condensate is the moisture that collects on the outside of a glass of ice water.


A part of an air conditioner which transfers the heat removed from the structure to another medium. An air cooled condenser transfers the indoor heat to outdoor air.


To dehumidify. To reduce, by any process, the quantity of water vapor within a space.

Design Temperature (Summer)

The maximum outdoor temperature, based on weather bureau records, for which an air conditioning system is designed to compensate. If the outdoor design temperature is 95° F and indoor temperature is 78° F, the air conditioning system must compensate for the 17° F temperature difference and hold the indoor temperature at 78° F.

Design Temperature (Winter)

The minimum outdoor temperature at which the heating system is designed to heat the house. Thus, if outdoor design temperature is 0° F, and the indoor design temperature is 70° F, the heater must maintain 70° F within the house at 0° F outdoor temperature.

Dew Point

The temperature at which the condensation of water vapor in space begins for a given state of humidity and pressure as the temperature of the vapor is reduced. Simply stated, it is the temperature at which the moisture in the air condenses.

EER (Energy Efficiency Ratio)

The ratio of output BTU’s to the input watts. The higher the EER the higher the output obtained for a given input, or stated another way, the higher the EER the less costly to operate the appliance.


A mesh like device that removes dirt, lint, dust and other impurities from the air passing through an air conditioning system.

Full Load Amps (FLA)

The steady state current (amps) of the equipment when all motors are running. Does not include start up current (amps).

Heat Gain

The amount of heat entering a space or an area. Specifically, that heat entering a house during the season of the year when cooling is desirable. It is the quantity of heat which has to be removed from a house in summer so that the indoor temperature and humidity will be maintained at the level necessary for human comfort. It is measured in BTU’s and BTU per hour (BTUH). The cooling capacity of an air conditioning system must, therefore, be equal to or slightly greater than, the calculated heated gain of the house it serves.

Heat Loss

The amount or quantity of heat escaping or leaving a space or an area. Specifically, that heat escaping from a house during the season of the year when interior heating is desired. It is the quantity of heat which must be supplied to the space to compensate for that which is escaping to the atmosphere or outdoors, to maintain comfort conditions within the house at design conditions. Thus, the heating unit must be large enough to compensate for the total calculated heat loss during minimum outdoor design temperature occurrence.

Insulation (Thermal)

A material having relatively high resistance to heat flow, and used principally to retard the flow of heat. Measured in R values.

Lock Rotor Amps (LRA)

Current (amps) required to start a motor. A high in-rush current that lasts for .1 to .2 seconds. If for some reason the motor does not start, the sustained high current level will trip the overload protector and take the motor off line.

MCA (Minimum Current Ampacity)

Used by electrician to determine wire size.

MMOC (Maximum Overcurrent Protection)

The steady state current (amps) of the equipment when all motors are running. Does not include start up current (amps).

Packaged Terminal Air Conditioner (PTAC)

AHRI defines a PTAC/PTHP in Standard 310/380 by requiring that it contain:

  • Cooling availability by means of a complete factory assembled refrigeration system consisting of compressor, evaporator, air or water cooled condensing means; a removable chassis on which the assembly is mounted.
  • Heating availability independent of cooling, with purchaser’s choice of use with hot water (hydronic), steam, electric (strip heaters) or reverse cycle (heat pump). System requires a means for forced heat-air circulation.
  • Integral or remote temperature and operating controls.
  • Wall sleeve, outdoor louver, and room cabinet.
  • Means for controlled force ventilation and filtering of all air delivered to the room.

Psychrometric Chart

A graphical representation of thermodynamic properties of moist air.

R Value

A number used to describe the resistance of a material to the flow of heat (thermal resistance). The larger the “R” value, the more difficult it is for heat to flow through that material.


A chemical compound, such as R-410A, R-22, R-134A, and others, which produces a refrigerating effect by its absorption of heat while expanding or vaporizing. It is reusable, not requiring replacement unless lost by leakage or contaminated with acid, water, other non-condensables, or foreign matter.

Relative Humidity (RH)

The amount of water vapor in the air at a given temperature, compared with (relative to) the total amount of vapor the same air could hold at the same temperature if it were 100 percent saturated with vapor.

Sensible Heat

That heat which changes only the dry bulb temperature of the transfer medium in heating and air conditioning. For instance, sensible heat will increase or decrease, as the case may be, the temperature of air in air conditioning and heating. Sensible heat has no effect upon the liquid state of water; only latent heat can change that.

Seasonal performance factor (SPF)

A measure of the additional energy (KWH) required for an electric resistance heat system as compared to a heat pump system to heat a given space. The higher the SPF the more economical operation of the heat pump system. For example, a SPF of 1.89 means that it takes 1.89 times more input energy (KWH) for the resistance heating system than it does for the heat pump system.

Split System

In air conditioning, a system in which the condensing unit may be located outside the conditioned space with the air handling unit, containing an evaporator coil and a blower assembly, located within the conditioned space.

Temperature (Dew Point)

The temperature at which the condensation of water vapor in space begins for a given state of humidity and pressure as the temperature of the vapor is reduced. Simply stated, it is the temperature at which the moisture in the air condenses.

Temperature (Dry-Bulb)

The temperature as read on a standard thermometer.

Temperature (Wet-Bulb)

Wet-bulb temperature is the temperature indicated by a wet-bulb thermometer constructed and used according to specification. Wet-bulb temperature will always be less than dry-bulb temperature, except in cases where 100 percent saturation (100% humidity) conditions exist.

Underwriters Laboratories (UL)

An independent testing organization which evaluates the performance and capability of electrical wiring and equipment, to assure that they meet standards for safety. Acceptance is usually indicated by labels on devices by showing the words “UL Approved” or “UL Listed.” All GE air conditioning units are “UL Approved.”

Vertical Air Conditioners (VTAC)

An air conditioner that has a vertical configuration and is typically installed in a closet-like corner enclosure in a room. Since these units are hidden from view, they provide a more ‘home like’ appearance. All vertical units must be controlled by a remote wall thermostat.

Voltage (Volts)

A unit of measure for electric pressure. The typical voltages applied to U.S. air conditioning are 208 volts, 230 volts, and 265 volts.

Wattage (Watts)

Unit of measure of electrical energy. One ampere of current flow at a pressure of one volt equals one watt of electrical energy. Utility costs are based on kilowatt hours (KWH) used, not voltage or current flow.