2.10.7.3 INTERNAL HEAT GAIN
The internal heat gain to the space due to different type of transformers
should be based on the following:
(a) Dry Type Transformers: 35 W (120 BTUH) Per KVA for 30 KVA through 112
KVA.
(b) Liquid Type Transformers: 15 W (50 BTUH) Per KVA for 225 KVA and larger
sizes.
2.10.7.4 VAULT CONSTRUCTION
For a non-sprinkled, oil-insulated transformer vault, the floor, the ceiling,
and the interior walls usually have a 3-hour fire rating and require a 3-hour
fire door in any duct penetration. Exterior walls, regardless of fire rating,
require 1 1/2 hour fire damper in penetrations if there is a window opening
above within 3 m (10 feet). With a sprinkled vault, the requirement for a
fire damper is waived.
2.11
EXHAUST SYSTEMS
2.11.1 GENERAL EXHAUST SYSTEMS
The exhaust systems shall be conventional, low pressure, low velocity type
serving toilets, day rooms, janitor closets, canopy type (A, B, and C) hoods,
soiled utility rooms, dark rooms, trash rooms, silver recovery rooms,
maintenance garages, etc. The exhaust systems shall also include areas, with
100 percent exhaust of the supply air, such as surgical suites, SPD areas
(less dedicated exhaust for Ethylene Oxide (ETO) Sterilizers), laboratories
(less special fume hoods), kitchen (less range hood), and animal research
(less special fume hoods).
2.11.1.1 In general, each supply air system shall have a corresponding
general exhaust system to comply with outdoor air requirements. The exhaust
system may or may not be interlocked with supply air system. It shall shut
down when supply air system shuts down during unoccupied hours to conserve
energy, except exhaust fans shall continue to run when smoke is detected in
the areas served by these fans. See Standard Detail 15900-11B.
2.11.1.2 Individual toilets and janitor closets, in general, draw make-up air
(exhaust air) from the corridors by using undercuts and/or door grilles.
Exhaust air shall not be drawn from the corridors through any storage room.
2.11.2 SPECIAL EXHAUST SYSTEMS
2.11.2.1 General
(a) The special exhaust system includes dedicated exhaust systems for
critical areas, such as isolation rooms, laboratories, SPD, autopsy, etc.
Each dedicated exhaust system shall have its own exhaust fan and ductwork. It
shall not be connected to the general building exhaust system or another or
another exhaust system.
(b) Each dedicated system has its unique set of requirements for air
quantity, filtration, construction of materials, type of discharge, controls,
emergency power, hours of operation, etc.
HVAC DESIGN MANUAL
2-30
HVAC SYSTEMS AND EQUIPMENT
Previous Page
