(3) Day Treatment
(4) Libraries
(5) Medical Records
(6) Nursing Administration
(7) Recreation
(8) Rehabilitation
(9) Retail Stores
(10) Security Offices
(11) Therapy Areas
(12) Volunteers
(d) The HVAC requirements for areas not listed above should be discussed with
the VA before proceeding with the design.
2.3
HVAC EQUIPMENT REQUIREMENTS
2.3.1 AIR HANDLING UNITS
2.3.1.1 The VA preference for air-handling units is for the draw-thru type.
2.3.1.2 The blow-thru type air handling units shall generally not be used
because the fully saturated air leaving the cooling coil could cause water
damage to the after-filters and sound attenuators, located on the downstream
side of the cooling coils. Exception: For any specific situation, if the use
of the blow-thru type air-handling unit is deemed necessary, locate the
after-filters on the upstream side of the supply air fans. And the duct-
mounted sound attenuators shall be located as far away as possible in the
supply air ducts, preferably on the downstream side of the air terminal
units. A factory fabricated diffuser section shall be installed on the
downstream side of the supply air fan to ensure uniform distribution of the
air velocity over the face of the cooling coil. Such a deviation should,
however, be reviewed with and approved by the VA before incorporating it into
the design documents.
2.3.1.3 All air-handling units comprised of coils, fans, filters, etc. shall
be of double wall construction. These units shall be factory-fabricated and
field-assembled. The larger units could, however, be field-assembled. See VA
Master Specifications Section 15763, AIR HANDLING UNITS, for further
information.
Casing sections and access doors are required as per VA Standard Detail
15763-0. Show access sections and door swings on contract drawings. The air
handling unit air pressure shall act to seal the access doors.
2.3.1.4 FANS: Airfoil (AF) or backward inclined blade fan wheels are
preferred. However, VA does allow forward curved blade wheels with certain
provisions. Refer to Fan Schedule listed in Handbook, PG-18-4, Standard
Detail No. 15000-21. For variable air volume systems, with supply fan motors
HVAC DESIGN MANUAL
2-5
HVAC SYSTEMS AND EQUIPMENT
Previous Page
