MD ANDERSON Project No. XX-XXXX
MD ANDERSON PROJECT NAME
A/E Project No.
Month, 00, 0000
Provide a thermal break between exterior panels and frame to ensure an air-tight fit. Configure casing assembly to eliminate all through-metal portions of the unit so that there will be no external condensation.
Panel surfaces shall be non-condensing per ASTM D 4230, Measuring Humidity with Cooled Surface Condensation.
Provide the access space sections for maintenance of individual components such as fans, filters, coils, humidifiers, etc., as scheduled or shown on the Drawings. Arrange these components in a manner that allows for ease of replacement. Provide a plenum section downstream of the cooling coil with sufficient width to contain all the moisture carryover from the cooling coils, before it reaches the next air handler component (such as filters, sound attenuators, etc.).
No field penetrations of the air handler casing are permitted.
All penetrations required to accomplish testing, balancing, to provide power to internal devices, and to provide control signals to and from control devices shall be made and sealed at the factory.
Coordinate with the manufacturer to allow for all necessary penetrations to provide a complete, functioning, and maintainable system. Internal control devices shall be shipped to the air handler manufacturer for installation at no cost to the Owner.
Provide IAQ style drain pan under the entire cooling coil section, which is in compliance with ASHRAE Standard 62.
Drain pan shall extend minimum 24 inches downstream of the cooling coil section and a minimum of 30 inches downstream of the final cooling coil bank for 100% capacity outside air handling units.
Construct drain pan of Type 304 stainless steel; minimum 14-gage on 100 percent outside air handling units and minimum 16-gage on 30 percent and higher recirculation air handling units.
Insulate the underside of the entire floor drain pan with two part sprayed on polyurethane closed cell foam with a minimum of R-14 insulation value. Insulation shall be water impervious rigid type, after curing, and shall occupy all voids and areas between drain pan and outer wall to prevent the occurrence of trapped water, condensation, and microbial growth. Install and seal insulation as is appropriate for the equipment construction.
Insulate intermediate drain pans to prevent the formation of condensation and to prevent condensation from dripping down the bottom and sides of the drain pans.
Slope drain pan in all planes to the drain connection to prevent accumulation of standing water. On units over ten (10) feet in width, slope pan to drain on both sides of the unit. Drain pan design shall be full inspection type and triple sloped to the drain connection to prevent accumulation of standing water to meet the requirements of ASHRAE 62.1.
The University of Texas
CUSTOM AIR HANDLING UNITS WITH FAN ARRAY SYSTEMS
MD Anderson Cancer Center
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