06-06
Mechanical Equipment
Ventilation
50
--
Rooms (MERS)
Only
Patient Rooms
76
50
78
30
Offices, Conference
78
50
72
30
Rooms
A. The indoor design conditions are not operating limits. All room
thermostats shall be adjustable between 60of and 85of with an
adjustable dead band (6of).
B. Mechanical cooling should be evaluated for the electrical equipment
room, elevator machine rooms, and transformer rooms if the summer
outdoor design temperature is in excess of 90oF; and where the use of
a ventilation system would create excessive air movement, in excess
of 30 air changes per hour.
C. Winter humidification for the office and bedroom areas shall be
evaluated for the areas where the outdoor design temperature is 0oF
and lower. The winter humidification system, if included, shall be
designed to maintain 30% RH.
D. The summer inside design relative humidity shown above need not be
maintained by any humidity control. This value merely represents the
design reference points; and, in actual practice, could vary with the
prevailing internal heat loads and coil leaving conditions.
E. Bathrooms and toilets do not require individual room temperature
control in cooling mode. Provide a terminal heating device and space
temperature control in heating mode for congregate baths and the
exterior bathrooms/toilets.
F. In the absence of any heat producing equipment, ventilation or
cooling/heating are not required for small electrical and telephone
closets. The storage closets, with areas less than 60 square feet,
also need not be ventilated or cooled/heated.
2.3 SUPPLY AIR REQUIREMENTS (MECHANICAL COOLING)
A. The supply air volume shall be established to meet the cooling load
requirements of the occupied space.
The supply air volume shall be
altered, if required, to meet any exhaust requirement.
B. If the HVAC system selection includes an all air, variable air volume
(VAV) system, the supply air volume, during part load conditions,
shall be established to ensure stable performance of the supply, and
more so, the return air fans.
The reasons for this requirement are:
1. The VA selected sequence of operation for the VAV systems is such
that a constant difference in CFM, amounting to the outdoor air
quantity for the air handling system, shall be maintained between
4
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