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York Air Handling Unit Chilled Water Coil - This coil is a cooling coil in a large commercial York air handling unit. The air handler serves approximately 80 VAV boxes and is responsible for providing cool conditioned air to all the zones the VAV boxes serve based on a set point determined in a DDC program and the chilled water coil seen here.
York Air Handling Unit Chilled Water Coil
The 80 VAV boxes that are served by this York air handler represent zones or temperature-controlled areas. The air handler is responsible for delivering a certain volume of air to all the VAV boxes. The air handler is only capable of delivering cold air or tepid air from the plenum return. It has no mechanical process to produce warm air. If the VAV zones need heat they have hot water reheat coils in them.
If the VAV zone calls for heat the damper limits the amount of air coming from the air handler and opens a valve to allow hot water to enter the reheat coil via a valve-operated actuator. This heats the air coming from the air handler and provides heat to the zone.
York Air Handling Unit Chilled Water Coil
The cooling coil in the picture is served by two large York chillers. The VAV boxes only have the ability to heat the air at the VAV box. If they call for cooling in their particular zone the cool air comes from the air handling unit.
The coil in the VAV air handling unit has an actuator controlled by direct digital control. The actuator opens a valve and allows chilled water to run through the air handling unit coil. This cools the air which is being delivered to the VAV boxes and the VAV zones. The air is returned to the air handler via a plenum above the ceiling.
York Air Handling Unit Chilled Water Coil
