Ahu Chilled Water Coil

Air handlers are part of a system using either a chiller with cooled water or a condensing unit in a direct expansion dx system.

Ahu chilled water coil.

That percentage reduction varies based on each coil s unique dimensions but a reliable estimate is a loss of 8 12. The chilled water enters the ahu fcu and passes through the cooling coil a series of thin pipes where it will absorb the heat of the air blowing across. The chiller produces chilled water and pushes this around the building to air handling units ahu s and fan coil units fcu s etc. When the chilled water leaves the cooling coil it will now be warmer at around 12 c 53 6 f.

How an air handler works ahu basics. Simply piping the coils in the correct manner from the beginning would seem to be the. This type of chiller needs a cooling tower to reject the heat from the building. This video depicts a technitian inside of a unit properly cleaning a chill water coil.

Dictated by local codes and based on the application each air handler will have a different set of needs including but not limited to fresh air intake humidity control heating filtration and energy recovery. The chilled water heats up and the air blowing across it cools down. The purpose of the valve is to control the amount of chilled water flow going through the coil. August 3 2020 december 9 2019 by trey.

The more chilled water flow that flows through the coil the colder the coil gets and the colder the air gets as it passes through the coil. If you opt to not counter flow a chilled water coil you ll have to reduce the coil s overall performance by a certain percentage. As warm air passes across the coil and comes in contact with the cold surface of the fins heat then transfers from the air to the water flowing through the tubes both cooling and dehumidifying the air. Chilled water coils are one of the most common mediums for cooling air.

In some cases we have to dismantle air handling units because of the difficulty in cleaning them. The coils can be either hot water coils chilled water coils or direct expansion coils with the direct expansion coils used as an evaporator coil in a refrigeration circuit. Comfort is so much more than temperature. Cooling moist air sensible cooling if the temperature on a cooling surface t c is above or equal to the dew point temperature t dp of the surrounding air the air will be cooled without.

There are some residential air handlers that use either a hot water heater or a boiler for a hot water coil located in the air handling unit.