Biomedical Engineering Reference
In-Depth Information
18 Hospital Power: Critical Care
JAMES F. NEWTON, P. E.
A severe thunderstorm, a construction crew
digging in the wrong place, an earthquake, hurri-
cane, ice storm, or even a squirrel that finds its
way into a substation can leave a medical facility
without normal power for a few minutes, a few
days, or even longer. The situation is further
complicated by the expectations of hospital admin-
istrators, doctors, patients, and the general public
that their hospital will be fully functional under any
circumstance, regardless of the unpredictability
or severity of the situation. Understanding code
requirements, performing a hazard vulnerability
analysis, and understanding what role the medical
facility has in the community during an emergency
are all essential to designing a safe and reliable
hvac system for a hospital (Figure 18.1).
The loss of normal power at a medical facility,
whether the result of a natural disaster or system
failure, is a situation that every health care engineer
must anticipate. Certain hvac equipment is required
by the National Electric Code or mandated by the
authority having jurisdiction (AHJ) to be connected
to the emergency power system of a hospital. Hvac
systems that are not code required or mandated for
connection to the emergency power system may
still need to operate to meet the facility's needs
during a number of critical situations.
Performing a hazard vulnerability analysis as
outlined by the Joint Commission on Accreditation
of Healthcare Organizations (JCAHO) is the best
way to begin to establish the extent of the hvac
emergency power requirements that are above the
minimum required by code or otherwise mandated.
The first step, however, is to understand the code
requirements.
18.1 Code Required Systems
The National Electric Code (NEC) and National
Fire Protection Association Standard for Health-
care Facilities (NFPA 99) require certain hvac
systems to be connected to the emergency power
system in a hospital. The following is a summary
of those hvac systems:
Generator-related equipment
•
Fuel pumps;
•
Damper operators and controls;
•
Ventilation and combustion air fans; and
•
Remote radiator fans.
Fire safety systems
Smoke control systems including exhaust fans,
air-handling equipment, and controls;
•
•
Stair pressurization equipment and controls; and
•
Kitchen hoods.
Heating equipment to maintain inside design
temperature where the outside design temperature
is lower than +20 ˚F
Figure 18.1
The 1.2 MW generators shown here are the heart
of the emergency power system at this hospital.
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