Heating & Cooling 101


The following products are called 'Unitary' air conditioners:
     • All Packaged Terminal Air Conditions (PTACs),
     • Vertical Terminal Air Conditioners (VTACs),
     • Window Room Air Conditioners (WRACs),
     • 26" Through the Wall Air Conditioners (TTWs)

Unitary systems are single units that provide both heating and cooling operations from one product. This is different from the air conditioning systems used in most North American homes which use split systems. This name is derived from the fact that two components are required to complete the system; an indoor coil (inside the home) and an external condenser (outside the home). Using electricity as its power source, the unitary system compressor pumps refrigerant through the system. The refrigerant attracts heat and moisture from indoors and then transfers it outdoors. Heat and moisture inside are removed when warm air passes over the cool indoor coil. The heat and humidity in the air are removed by the coil, thereby "cooling" the air indoors.

When the unitary system operates in the heating mode, the unit operates in reverse. The refrigerant is used to create a heated indoor coil. As air passes over the heated coil the heat is transferred to the air inside the room creating warm air.


Indoor comfort all year – Unitary systems can rapidly remove heat and moisture from indoor air. You simply set the units thermostat to the temperature that you desire and the unit automatically cools to that level. You can manually select fan speed or use the automatic fan speed setting. When you need the room to be heated you use the same basic settings. Just set the thermostat to the temperature you want and select the heating function.Simple Installation – Unitary systems are easy to install because they come in standard sizes and shapes. Regardless of the heating and cooling load requirements, the unit is the same size. Since both the heating and cooling systems exist inside a single unit, installation is easier than the installation of a split system.Independent Operation – Unlike split -system heating and cooling systems which condition whole buildings through the use of ductwork, unitary systems cool and heat only the rooms or spaces where they are installed. This means you cool or heat only what you want with individual temperature control. With multiple unitary systems installed, you can easily control indoor temperature on a room to room basis.

Amana PTAC Interior and Exterior

PTAC Interior and Exterior