Table 3-2 Medical Media Service

(e) Return Air System:

(1) The return air system shall be used if the return air volume is at

least 35 percent of the total supply air volume. When the return air

volume is below 35 percent of the total supply air volume, the air-

handling unit shall use 100 percent outdoor air and the total supply air

volume shall be fully exhausted outdoors.

(2) With a return air system, a return air fan shall be used to ensure

proper air balance, if deemed necessary. The air handling unit shall be

equipped with an economizer cycle for "free cooling" to conserve energy.

3.16.5.2 Cooling: The MMS air handling unit shall be served by a dedicated

air-cooled chiller to ensure the lower cooling temperatures required in

the space. Air-cooled chiller will also ensure availability of chilled

water whenever the central chilled water plant is not operating.

3.16.5.3 Heating: For heating, steam from the central boiler plant and/or

hot water generated by the steam to hot water heat exchangers shall be

used. For locations qualifying for perimeter heating, finned tube

radiation or overhead radiant ceiling panels shall be provided. The

perimeter heating shall be controlled by the room thermostat such that

cooling and heating do not come on line together. See Paragraph 2.7.2.

3.16.5.4 Exhaust System: A dedicated general exhaust system shall be

provided to service the MMS. The exhaust air system shall be interlocked

with the air-handling unit.

Table 3-2 Medical Media Service - Core Areas

Air

Room

Air

Exhaust/

Room Name

Indoor

Pressure

Temperature

Changes/Hr

Recirculation

Design

Control

Air

Conditions

Darkroom

Special

Darkroom

(Printing &

Enlarging)

Photo Finishing

Special

General

Special

Photo

Studio/A.V.

Recording (See

Notes (a) and

(b)

Photo

Special

Micrography

Camera Copy

Special

General

Audio Visual

Equip. Storage

/Checkout (See

Note (c)

HVAC DESIGN MANUAL

3-15

HVAC REQUIREMENTS FOR OCCUPIED AREAS