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Natural VentilationWhile operable hospital windows are primarily intended
for emergency use in the case of fire, there are other
situations in which patients, nurses or other staff may
desire natural ventilation. Nasty spills or smells may need
to be quickly “aired out”, a power failure or equipment
failure may temporarily disable fans or a breath of fresh
air on a pleasant day may simply be “just what the doctor
ordered”. Even when windows have access control locking
devices, keys are commonly available at the nursing station.
With recent reports of “sick building” syndrome,
indoor air quality is certainly a topic of concern for anyone
in building management or the construction industry.
DaylightingIn other building types, studies have documented the
salutary effects that natural daylight and ventilation
have on office worker productivity and wellness, as well
as student learning. There is no reason to doubt that a
similar phenomenon would be noted in patient recoveries.
Recognizing this, the AIA’s 2001 Guidelines for Design
and Construction of Hospital and Health Care Facilities
paragraph A7.2.A3 states, “Windows are important for
the psychological well-being of many patients, as well
as for meeting fire safety code requirements.”
CleaningCertain operable windows are designed so that maintenance
personnel can clean the outside glass surface from the
interior. This ease of maintenance not only improves
building appearance and staff safety, but may also represent
a life cycle cost savings since product maintenance may
increase service life.
A Balanced ApproachAs a standard setting organization, AAMA recognizes that
due to the general nature of any code or standard, it is
difficult to prescribe whether operable or fixed windows
are the appropriate choice for all hospital applications.
However, a balanced assessment of operable windows
versus “break out” fixed glazing or mechanical emergency
ventilation is in the best interest of the building team,
owner, staff, occupants, and local protective services,
especially in a hospital environment.
Code Change ReferencesThe American Institute of Architects (AIA) 2001 Guidelines
for Design and Construction of Hospital and Health Care
Facilities, and the National Fire Protection Association
(NFPA) 2000 Life Safety Code Handbook have eliminated
requirements for operating windows to provide emergency
ventilation for patient rooms in the case of fire.
AIA 1996: “Patient rooms or suites in new construction
intended for 24–hour occupancy shall have windows or vents
that can be opened from the inside to vent noxious fumes
and smoke products and to bring in fresh air in emergencies.
Operation of such windows shall be restricted to inhibit possible
escape or suicide. Where the operation of windows or vents
requires the use of tools or keys, these shall be on the same
floor and easily accessible to staff. Windows in existing buildings
designed with approved engineered smoke control systems may
be of fixed construction.”
AIA 2001: “Operable windows are not required in patient
rooms. If operable windows are provided in patient rooms or
suites, operation of such windows shall be restricted to inhibit
possible escape or suicide.”
NFPA 1985: Every patient sleeping room shall have an
outside window or outside door arranged and located so that it
can be opened from the inside to permit the venting of products
of combustion and to permit any occupant to have direct
access to fresh air in the case of emergency. The maximum
allowable sill height shall not exceed 36 in. (91 cm)… keys
shall be located on the floor involved…accessible to staff.”
By NFPA 1997, the specific requirement for operable
windows had been removed, but the commentary below
had not yet been added.
NFPA 2000: “Paragraphs 18.3.8.1 and 19.3.8 requires an
outside door or outside window in each room where patients
sleep. The window is not required to be operable. A maximum
allowable sill height of 36 in. (91 cm) is specified for new health
care occupancies…. Sill height is limited in new construction
to ensure access to the window should it ever need to be used
for ventilation purposes…”
OPERABLE WINDOWSIN HEALTHCARE FAC IL I T I E S
P L A N N I N G F O R
PatientSafety
AMERICAN ARCHITECTURAL MANUFACTURERS ASSOCIATION
The Source of Performance Standards, Product Certification,
and Educational Programs for the Fenestration Industry.SM
WWW.AAMANET.ORG
AMERICAN ARCHITECTURAL MANUFACTURERS ASSOCIATION
1827 Walden Office Square, Suite 550
Schaumburg, IL 60173-4268
(847)303-5664
FAX (847)303-5774
WWW.AAMANET.ORG
An Architect’s PerspectiveRegistered Architect Gene Wells of Marshall Erdman
& Associates, a leading national health care design and
construction firm, offers the following: “In today's hospital,
huge efforts are being made to create a healing environment
for patients and their families. A non-institutional approach
lessens the stress level for people who already
have too much stress and leads to better
outcomes. Patient's rooms, in particular,
are often designed to reflect local
culture, connect with nature or create
a hotel-like environment. Operable
windows can be an integral part of
this atmosphere.”
She adds, “The issue of control is
also important. Operable windows can
give patients a small controllable
piece of an environment
in which they may feel
like they have very
little control. This can
increase patient satisfaction, even if
they never actually open the window.”
Operable WindowsBEYOND F IRE SAFETY
Energy Savings and Environmental ImpactIn many parts of the U.S., natural ventilation offers a
seasonal opportunity for air-conditioning energy savings
if included as part of the HVAC design, balancing and
operating plan. Recognizing their sustainable design
benefits, the U.S. Green Building Council LEED™
Rating System awards points for operable windows
in the “Ventilation Effectiveness” and “Controllability
of Systems” credit categories.
Fire Safety AlternativesThe AAMA “Window Selection Guide” (WSG.1-95) states,
“Most deaths occur in fires because of suffocation, not
because of burning.” This fact becomes especially important
in hospital patient rooms considering that, according to
the NFPA Life Safety Code® Handbook, 2000 edition,
“Unlike most other buildings and use groups addressed
by the Code, the least desirable emergency action in a
health care occupancy is the wholesale relocation and
evacuation of patients. For this reason, a defend-in-place
strategy is used … During a fire, the emergency evacuation
of patients in health care facilities is an inefficient, time-
consuming process.” This suggests that smoke control
options should be key considerations when designing
hospital patient rooms.
Operable WindowsIt is the condition of the patient nearest the fire that
is most relevant when considering the use of operable
emergency ventilation windows, which may relieve
smoke in the immediate area without spreading
it into previously unaffected areas.
Smoke DampersThough often considered the “first line of defense” against
the spread of smoke from room-to-room, dampers are not
always required by code in ducted barrier penetrations in
hospitals. Some provisions are designed to protect occupants
in other areas such as the Florida Administrative Code
(ACHA) Chapter 59A-3 which states, "During a fire
alarm, fan systems and fan equipment shall be stopped
or controlled to prevent the movement of smoke by
mechanical means from the zone in alarm.” However,
stopping fans also naturally slows the exhaust ventilation
of the area near the fire.
Engineered Smoke ControlIn some local code jurisdictions, complex “engineered
smoke control” systems may be used. As an example, the
Massachusetts State Board of Building Regulations and
Standards 780 CMR 921.2 states, “[Mechanical] provisions
[can] be made for smoke removal from the space at a rate
of not less than two changes per hour … moved directly
to the outside without re-circulation to other areas of the
building.” The Florida Building Code Section 412.5
requires six changes per hour and adds, “…the air handling
equipment [must be] connected to the standby power and
light system.” NFPA requires that such smoke control
systems be fully tested on a periodic basis and designed
as “fail-safe” in a power outage or equipment failure.
Paragraph A7.2.A3 of the AIA’s Guidelines for Design
and Construction of Hospital and Health Care Facilities,
2001 edition, states, “Windows … are also essential for
continued use of the area in the event
of mechanical ventilation
system failure.”
Evaluating CostsIn the absence of operable windows, the designer must
pay particular attention to special mechanical requirements
and assess the incremental costs involved in analysis,
equipment and installation, as well as the adequacy of
the smoke exhaust rate in a fire emergency.
An operable side-hinged in-swing casement vent at
every third lite usually adds about 10% to the average
installed cost of a fixed strip window system of comparable
performance and features. This added cost should be
weighed against the cost of the “engineered smoke control
system,” recognizing that operable windows offer more
benefits than just those related to fire safety.
n Fully Tempered Safety Glass – This glass is even more
difficult to break since it is at least four times as strong
as annealed glass, although it does shatter into small,
relatively harmless fragments. If the force of a blunt
object fails to break tempered glass, a sharp pointed
instrument or object is typically effective.
n Special Glass Types – In some cases, laminated acoustical
glass, hurricane impact-resistant glass, psychiatric glass
or polycarbonate are required and will present an
effectively impenetrable barrier to occupants and staff.
In these cases, glass breakage cannot be expected and
emergency ventilation must be accommodated another
way.
Irreversible – In some instances involving differential
atmospheric pressure, the introduction of added oxygen
from an open window could actually make a small fire
more difficult to contain. Since operable windows can
be re-closed, the flow of oxygen exacerbating the fire
can be stopped.
Glass RemovalArchitectural framing systems require specialized knowledge
and tools to deglaze and, in most cases, cured sealants
must be cut. While complete glass removal might appear
to be a preferred alternative to glass breakage, it is simply
not realistic.
Registered Nurse Margaret Zvoda notes,
“In the case of fire, it is the nurse’s
primary responsibility to calm patients
and ensure their safety. Whether they are
ambulatory or in need of complete bed rest,
it takes time for a nurse to prepare them
to move out of a smoke-filled room.” She
adds, “Instant access to fresh air would
help immeasurably. Either patients or
nurses could be asthmatic, adding to
the urgency of the situation.”
A Nurse’s Perspective
The Practical Side of Glass Breakage or RemovalIt is assumed that fixed glass could be broken out in case
of emergency for ventilation in typical patient rooms.
While professional emergency responders, with special
tools and training, may meet fewer challenges when
attempting this, it is typically a member of the nursing
staff who is first on the scene and may have difficulty
breaking the glass in commercial windows.
Glass Breakage ChallengesGlass Thickness – To ensure structural integrity, 1/4”
(6mm) or thicker glass is typically specified for non-resi-
dential applications. Even non-heat-treated annealed 1/4”
glass is difficult to break unless employing a heavy object
or other tool with a sharp, tough edge. Panic, confusion,
integral Venetian blinds, window coverings and reduced
visibility in a smoky room all add to the difficulty.
Broken Glass – Injury hazards may exist when glass is
broken out of a window.
n Standard Annealed and Heat Strengthened Glass – These
types of glass lites break into large fragments which
may remain in the opening and the sharp edges pose
a serious hazard to people on the inside and outside.
WindowsWindows are expected to meet a variety of
objectives in building projects – lighting,
ventilation, aesthetics, security, building
envelope protection, thermal performance,
emergency escape and rescue, and more.
To meet these objectives, numerous factors
must be considered when selecting windows
for any building application; however,
healthcare facilities, like hospitals, require
some additional attention considering the
purpose and occupants of the building.
Based on this concept, architects should
carefully evaluate and accommodate fire
safety needs for hospital applications.
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