HVAC Air Handling Unit (AHU) Receiving, Handling, Storage and Preservation

This article is about HVAC Air Handling Unit (AHU) Receiving, Handling, Storage and preservation as per International Codes and standards.

HVAC Air Handling Unit (AHU) Receiving, Handling, Storage and preservation

HVAC Air Handling Unit (AHU) Receiving

1. Visually inspect all incoming material /equipment for damage.
2. An identification tag or name plate made of 316 stainless steel or better, shall be attached to each equipment unit, securely with stainless steel or Monel fasteners.
3. The tag or name plate shall be marked by raised letters or die-stamping with at least the following information:
   a) Purchase Order Number b) Manufacturer c) Part/Model No. d) Serial No. e) Date of Manufacture f) Mark/Tag No.”
4. AHUs casings shall be manufactured, pre-painted baked enamel finish, 18 gauge minimum galvanized steel with structural steel frame and bracing.*
5. Casing panels shall be insulated with 25 mm (1 inch) minimum thickness of fire, rot, rodent and water resistant material with a density of not less than 48 kg/m³ (3.0 lb/ft³).*
6. Outside air/return air mixing plenum shall include opposed blade dampers for both the return and outside air streams. Automatic proportioning dampers shall be provided between the outside air and return air*.
7. Mixing plenum shall include baffles or other provisions to insure complete mixing of outside and return air streams at all flow rates*
8. Casings shall include doors to provide maintenance and removal access for all fans, motors, coils, filters, and humidifiers.
9. Access doors or frames shall have resilient gasketing material to prevent air leakage. Access doors shall have corrosion-resistant hinges and positive latches.
10. Casing filter mounts or filters shall have seals to prevent air bypass.
11. Reciprocating compressors shall be vibration isolated from the unit.

AHUs with total supply air equal to or greater than 5,000 ft³/min shall, in addition to the above requirements, have the following:

1. The structural frame and bracing shall be constructed of steel or extruded aluminum and structurally reinforced for rigidity.*
2. The entire AHU shall be minimum two inch, double wall construction. Casing panels shall be fabricated with a minimum of G-90 galvanized steel or aluminum with all necessary reinforcements to prevent pulsation and bulging*
3. AHU panels shall have galvanized steel with pre-painted backed enamel finish or aluminum exterior skin and a solid aluminum inner lining.
4. Insulation shall be sandwiched within the AHU panels with a minimum of 2″ glass fiber insulation having a density not less than 48 kg/m³ (3.0 lb/ft³).*
5. Casing panels shall be airtight without caulking.*
6. Insulation shall be secured with 100% coverage of waterproof adhesive.
7. Casing shall completely enclose all AHU components
8. The AHU shall have a structural steel base with cross members adequate to support all AHU components. The unit floor shall consist of a minimum 18 gauge galvanized steel or 0.040″ aluminum outer panel, three inches of glass fiber insulation and a 0.063″ aluminum inner panel*.
9. Drain pans shall extend completely under the coil sections and shall have minimum 1-¼ inch threaded drain connections.
10. Drains pans shall be sealed, double wall steel construction with rigid glass fiber insulation and Type 316 stainless steel inner pan*.

Air Handling Unit (AHU) Handling, Storage and Preservation

Verify that approved procedures for handling, storage and preservation lists all the required inspection schedules for maintaining the quality of AHU.

* Verification is required by checking the equipment submittal if verification is not possible by visual inspection.

Standards Codes and References HVAC Air Handling Unit (AHU) Receiving, Handling, Storage and preservation

1- SAES-K-001 – Heating, Ventilating and Air Conditioning (HVAC).
2- Uniform Mechanical Code (UMC), 1997.

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