Air-handling unit


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air-handling unit

[′er ¦hand·liŋ ‚yü·nət]
(mechanical engineering)
A packaged assembly of air-conditioning components (coils, filters, fan humidifier, and so forth) which provides for the treatment of air before it is distributed.

Air-handling unit

Heating and/or cooling distribution that channels warm or cool air to different parts of a building. Equipment includes a blower or fan; heating and/or cooling coils; and related equipment such as controls, condensate drain pans, and air filters. It does not include ductwork, registers, grilles, boilers, or chillers. Conditioning may include particle filtering, adding or removing heat and moisture. A varying portion of the return air from the conditioned space may be recirculated and mixed with incoming air.

air-handling unit; packaged fan equipment

An assembly of air-conditioning components (such as fans, cooling coils, filters, humidifiers, and dampers) integrated into a self-contained package and often installed as a single unit, which is connected to system of metal ductwork that distributes the conditioned air.
References in periodicals archive ?
Using the coil bypass air-handling unit for healthcare applications, particularly surgical suites, has control implications that usually don't apply to underfloor air or displacement ventilation applications.
* Alternative 1: Install a steam humidifier for the dedicated fresh air-handling unit;
A discussion of the minimum outside air portion of the two fan dual duct system, the function of the air-handling unit warm deck heating coil and terminal reheat coil will follow later after the establishment of the energy use advantages of the system.
Were a fire to break out in, say, a trash can in the conference room, the suction of return air by the air-handling unit in the corridor would tend to draw smoke from the conference room out into the corridor--the very corridor that is needed for safe egress by building occupants.
Barrie Graham, P.E., and I were preparing the content for the first ASHRAE Professional Development Seminar Series entitled 'Air System Design and Retrofit for Energy/Cost Effectiveness." The issue of air-handling unit selection based on coil face velocity was very much on our minds since many calculations on previous projects we were involved in indicated, from a return on investment basis, that lower face velocities than 500 fpm often made good economic sense when the cost of energy was considered.
And, the 20-ton air-handling unit required a perimeter room of approximately 400 square feet to house it, further increasing the loss factor and the effective rental cost per square foot.
Two additional coils sandwich the cooling coil of the laboratory air-handling unit. Warm outdoor air flows through the first coil, heating the water flowing within, then flows through the cooling coil, where it is cooled to the required dew-point temperature (usually 54[degrees]F [12[degrees]C] or less), then flows through the downstream coil, where it is warmed by the circulating water that was heated by the air when it flowed across the most upstream coil.
In a building served by a chilled beam system, the air-handling unit no longer provides primary load conditioning; it provides only the air required for beam activation and ventilation.