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| Location |
Preferably, a low
profile location away from obvious hazards such
as water, fuel stores, high voltage electricity
and vibration sources. Where possible have another
floor above the room – roofs leak. Remove
fire and water hazards from adjoining areas and
floors. |
| Walls |
Materials
Headings, which follow this one, help to determine
the best form of construction for the containment
walls. However consideration needs to be taken
of the consequences of possible future expansion
of the space, the relocation of walls and the
possible deleterious affects to the computer environment
whilst demolition is taking place.
Fire resistance
Walls need to be a minimum of 1Hr fire resistant
and decorated to provide Class O flame spread.
When 2Hr separation is called for, its restrictive
effect on access to the room via similarly fire
rated doors needs to be considered. Material consideration
needs to include floor slab loading.
Blast
Where applicable, blast resistance needs to be
taken into account when construction materials
are chosen because some merely become shrapnel
inside the room.
Acoustics
Computer rooms are extremely noisy – generated
by the motors inside the computer equipment and
the airflow passing through them. Added to this
is that from the air conditioning equipment and
the air turbulence it produces – at low
frequency. There are several means of preventing
transmission through the fabric into adjacent
workspaces.
Pressure & vapour
The walls and their abutments need to be airtight
to both contain the conditioned air inside the
computer room and to prevent polluted air being
drawn into it in low pressure zones which occur.
The computer room humidity is maintained at an
artificially high level.
The fabric of the room needs to be vapour sealed
to prevent water vapour migration to adjoining
less humid areas. |
| Floor Slab |
Seal &
Insulation
The floor slab needs to be insulated where possible
to do so – to reduce heat sink effect, and
have it's surface sealed against dusting whilst
exposed to moist cold air circulation.
Strength
It needs to have structural strength sufficient
to support the weight of computer equipment –
which can be extremely heavy. It needs to have
structural construction such that it will support
and distribute the superimposed point loads exerted
by the pedestals supporting the raised floor –
so as not to permit punching shear or collapse.
Vibration
The rigidity of the slab should be such as not
to transfer vibration into the room from external
sources. Otherwise its perimeter should be isolated,
in the case of RC construction; and mounted
on anti-vibration pads, in the case of steel
frames.
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| Drains |
Rainwater
Any rainwater downpipes need to be sealed, boxed-in
and isolated from the computer room so that leaks
will not flood the room space.
Drain access traps, manholes and the like, need
to have double seals and screw-down covers to
resist internal pressure.
Valley gutters occurring above, or even in close
proximity to the room need special attention to
prevent leaks. The gutter itself should be underlined,
to catch any leaks. The gutter and its outlets
should be regularly cleaned and maintained.
It should be checked that an overflow facility
is incorporated in the roof gutter design such
that rainwater cannot build-up in the valley,
regardless of the condition of the rainwater downpipes and the surface water or combined drains
which they are connected into.
Special attention needs to be paid to symphonic
roof drainage systems in which high pressures
develop in small-bore pipes. They depend on a
high degree of maintenance both above and below
ground and are severely affected in the event
of seals breaking or ground water flooding the
underground chambers into which they discharge.
Condensate
Condensate drains need to be run in brazed jointed
copper pipework and/or routed to leave the room
as soon as soon as possible.
Non-gravity drains need dual run/standby pumps
housed in watertight containers – inside
the room or in a secure area adjacent.
Drain traps exposed to room conditions will dry
out and should be sealed.
A drain point in the room slab should be available
for the removal of water in the event of a flood. |
| Ceiling
Slab/Roof |
The ceiling slab/structure
needs to be insulated, contain a vapour barrier
and be airtight.
It also needs to be watertight/waterproof.
In the case of the ceiling slab being a floor
for the area above it – see Floor
Slab. It needs to be structurally capable
of supporting the load of a suspended ceiling,
its insulation, light fittings and gas flood and
refrigeration pipework and cable distribution.
In the sketch perspective, the steel roof portal
dimensions should not automatically suggest that
sufficient support is available. The dimensions
will usually reflect the span of the frame and
its support requirements.
Where the ceiling is a secondary internal structure,
as sketched above, access behind it is necessary
to attend to problems of leaks and the like that
might occur from the roof above it.
In the case of a roof being above, any roof lights
should be blocked out by either with replacement
roof sheeting, or by the application of solar
reflective paint.
Vent ducts and the like in a roof are a source
of rainwater ingress. They should be removed or
their weatherproof integrity checked and safe
maintenance access to them ensured. |
| Doors |
Doors contained in
the perimeter walls of the room need to be solid-cored
and fire resistant to the same rating as the walls
in which they occur. 2Hr+ doors will restrict
free access to the room – there are several
options to overcome this.
Vision panels need similar fire rating.
Door furniture needs to conform to the requirements
laid down for fire doors.
Door locks in the event of a fire alarm, shall
not hinder egress from the room. Either the locks
will be operable from inside the room, or they
will fail safe.
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| Windows |
External windows are
unnecessary. They are environmentally hostile
to a computer room.
They should be sealed and blocked in. Large openings
may be usefully modified for equipment access.
Internal viewing windows need to be constructed
to achieve the same fire rating of the walls in
which they occur.
A clearer view through – for display areas,
is achieved by inclining them.
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Suspended
Ceiling |
Suspended ceilings
need to be non-dusting and acoustically absorbent.
They also need to be moisture tolerant/resistant
– because relative humidity in the room
is maintained and the tiles will otherwise absorb
the moisture.
Free access behind is required for service and
maintenance, as well as for use of the void for
the passage of cabling. |
| Decoration |
Walls need to have
Class O flame spread. In practice, this means
that they may be decorated with emulsion paint
or vinyl wall cloth.
The relative cost of each depends on the obstacles;
in terms of wall mounted equipment and partition
cover strips.
Vinyl emulsion provides a surface that can be
cleaned as easily as wall cloth. It is however
easier to maintain. |
| Raised
Floors |
The raised modular
floor should comply with the relevant MOB grading
standard – usually heavy or extra heavy
duty.
Heavy duty will suffice in most cases –
dependent upon anticipated loading. Local reinforcement
is always possible for isolated items –
such as data safes.
Mechanical fixing of the pedestals to the subfloor is necessary, when the floor height exceeds
a certain level. This is to prevent floor collapse
when loads are being moved whilst tiles are not
in place. Interesting problem when the subfloor
comprises wood blocks!
The surface covering of the floor panels needs
to be non-static forming and non-dusting.
Carpet finishes will shed fibres, but also hold
particulate within their pile and absorb sound.
PVC coverings shed small amounts of fine particulate
and do not hold dust. They also reflect sound.
underfloor void obstacles such as drain covers
and buried services ducting, may be bridged with
steelwork to permit the uninterrupted layout of
floor pedestals.
Consideration regarding service access needs to
be built into the design of such bridging.
subfloor strengthening may be required in the
case of certain types of construction –
to spread the point loads, and prevent punching
shear. |
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