September_1967 — Page 29

Engineering Services at the British Military Hospital

s with any modern hospital, the

A engineering services form an es-

sential and integral part of the hos- pital design and planning arrange- ment. In addition to the usual engineering services that are required for a building, e.g. air conditioning and water supplies, the requirements of a modern hospital call for other specialised services such as a diesel generator to provide emergency elec- trical supply, a doctors' call system. piped medical gases, chilled drinking water, etc.

Air Conditioning

During the planning of the hos- pital it was decided that air condi- tioning would not be provided for the general ward areas and that advantage would be taken of the exposed site to benefit from natural cross ventila- tion. The general ward areas are however heated during the cold wea- ther by means of mechanical warm air ventilation.

Approximately 20 per cent of the hospital is air conditioned. The air conditioned areas on each floor are mainly in the centre of the building so as to keep to a minimum the duct- work from the centrally located air handling plant on each floor to the various rooms.

The operating theatres are air conditioned with individual plants that are served from chilled water pipes and refrigeration plants located in the basement. Naturally, the tem- perature and relative humidity within the operating theatres are fully auto- matically controlled to satisfy the surgeon's pre-selected temperature and humidity requirements.

In order to reduce the possibility of creating electro-static electricity within the theatre, an in-belt safety control ensures that the relative humidity never drops below 55 per cent. ir- respective of the pre-selection of conditions made by surgeons.

The air distribution arrangements for the theatres are illustrated in Figure 1. The supply air is discharg- ed from ceiling level and air leaves the theatres at floor level. This ar- rangement has the advantage of clean supply air passing directly across the patient and attending medical staff

The air supply arrangements have been designed so that the air pressure within the theatres is higher than ad- jacent rooms, this is to ensure that when theatre doors are opened air moves from the theatre to adjacent rooms and not vice versa as this could cause contamination of the theatre air.

The central sterile supply depart- ment is also air conditioned and in order to reduce the heat load of the air conditioning plant the autoclaves have been arranged so that they are in a separate room from the sterile area with only the autoclave doors opening to the sterile area, With this arrangement it has been possible to ventilate the autoclaves themselves without in any way affecting the air conditioning plant for the sterile area.

Water Services

The Public Works Department arranged for a supply of sea water to the hospital by means of a pipe line from the harbour at Hunghom; in addition to supplying water to the hospital the system also supplies the nearby Queen Elizabeth Hospital. This sea water is used for cooling the refrigeration machines and in addition feeds tanks at ground floor level for the flush water systems.

Tanks are also provided at ground floor level to receive fresh water and from these fresh and flush water tanks water is pumped to roof tanks in various buildings. From these elevat-

ANCILLARY ROOMS

which assists in off-setting the heat Fig. 1. gain experienced from the scialytic theatre light fittings.

Far East Architect & Builder September, 1967

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ed tanks water is supplied by gravity to the water fittings.

Piped hot water is provided for the hospital and a total of approximately 4,000 gallons of hot water is stored in cylinders, the water being heated by steam coils supplied with steam from the boilers.

Chilled drinking water is provided by individual electrically operated water coolers installed at various locations in the hospital and staff quarters buildings.

Fire Fighting Equipment

Fire points are provided at numer- ous locations throughout the buildings and each point comprises fire ex- tinguishers, a hosereel of 3⁄4 in. or 1 in. tube size together with a landing valve. The system is arranged so that the action of using a landing valve or hosereel automatically starts a fire pump located at ground floor, this fire pump is driven by a diesel engine so that it can function regardless of a power failure in the electrical sup- plies.

In order to avoid excessive pres- sures at landing valves in the lower portions of the building, valves are provided with special reducing devices so that the pressure does not become excessive.

For the hospital itself, the fire alarm system is such that should the alarm be raised only the floor con- cerned is activated. This was arrang- ed deliberately so that in the event of a false alarm there would not be needless alarms on other floors.

In addition to the alarm sounding on the floor concerned, indicator boards are provided at senior staff locations and in the telephone rooms. The senior staff officer can then decide the extent and validity of the alarm and take appropriate action. For the domestic buildings a conven- tional alarm system is installed in that alarm bells ring on all floors should an alarm be activated on any one floor.

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