The present invention pertains to heating, ventilating and air conditioning (HVAC) systems in general, and to an air handling unit arrangement in which a direct expansion coil is utilized.
In some buildings, typically high rises, it is common to use one or more small air handling units per floor. These systems have the advantages of being inexpensive to purchase and install and a self-contained system may be provided for each tenant. For example, each floor of a high-rise building may therefore have one or more small air handling units.
Such systems are characterized by recurring problems related to equipment failure and occupant discomfort. The recurring equipment problems can be identified as being related to icing of the expansion coil and cooling compressor seizure.
The occupant discomfort problems typically are associated with wide variations in temperature due to compressor cycling and excessive removal of moisture from the air.