Single Zone - Description

A single-zone system is best described as a constant volume, variable air temperature distribution a system. As the name implies, a single-zone system commonly serves one thermal zone or multiple zones with loads that react, at least thermally, in a similar manner.

This system features a fan moving a constant volume of air through a coil and into the zone. It may be a cooling or heating coil or both. The system airflow is usually equal to the sum of the individual peak air volumes in each zone. The leaving air temperature is typically controlled by a single, adjustable thermostat centrally located in the thermal zone.

An example of a common single-zone system is a single-zone rooftop. This is simply a packaged air conditioning unit with both air-side and refrigeration-side components in a common casing. It is made for outdoor installation, and is typically installed, as the name would imply, on the building's roof. A rooftop unit discharges air through ductwork and into the zones through diffusers. A thermostat is strategically located in one zone, and provides leaving air temperature control units. A building may have one or several rooftops units depending on the number of zones or tenants, and the load and use characteristic of each zone.