there is a considerable difference in temperature obtained in the buildings when mechanical ventilation is utilis- ed and without ventilation of any sort buildings 3, 4 and 5 would be unin- habitable.
As would be expected the slope of any one of the curves 1 to 5 indicate that as the air quantity for a building is increased then the temperature ex- perienced will be reduced, however the different slopes show that the actual air change provided for a building is not in itself the sole con- tribution to the conditions that would be obtained as the characteristics of the building structure also have an effect on this.
Inspection of the calculations reveal certain interesting points regarding the desirable structural features of a building in order to keep temperature conditions to a minimum if ventilation is to be utilised.
Apart from the obvious considera- tions such as the provision of sun breakers to reduce solar heat gains. all walls that are shaded from the sun should be constructed to have a high thermal transmittance, double glazed windows should be avoided and pro- vided they are constantly in the shade the increase of window area will help to keep the internal tempera- ture to a minimum.
Ventilation systems are also install- ed in a building for purposes of con- trolling the flow of air from various spaces such as lavatories, garages, etc. and as a guide to the design basis of such systems Table 2 gives details of these.
Electrical services
The electrical services and works within a building can
range from transistorized equipment where the power consumption is almost micros- copic to very large industrial motors required to drive refrigeration ma- chinery.
Probably the greatest difficulty that an electrical engineer encounters in designing the services for a building is to determine exactly what equip- ment and devices are to be installed which will require an electrical sup- ply.
Apart from the obvious require- ments of electric lighting and power, a supply of electricity may have to be provided for closed circuit television, accounting machines, burglar alarms and many other specialized require- ments depending on the type and usage of the particular building.
To ensure that the requirements of electricity for a building are assessed accurately it is essential that the elec- trical services engineer works most closely with the building owner, architect and other service engineers. Failure to achieve this co-ordination can only result in a system of com- promise and a continual hope that the electrical distribution system in the building can withstand the ever in- creasing loads that are imposed on it. The electric lighting that is provid- ed for a building is quite often the
Far East Architect & Builder October, 1965
18 IN
result of a 'tug of war between the architect and the services engineers: the architect is usually very concerned with the planning and selection of the lighting fittings to create the desired effects in the various spaces of the building whereas the services engineer is more interested in the functionabili ty of the lighting fittings and the technical performance that the light- ing can achieve.
The author would not like to come down heavily on either side of this controversy but to venture the opinion that the architect must be the prime mover in the selec- tion of the lighting fittings but should consult with the services engineer to ensure that the lighting intensity, glare factor, etc. will be suitable for the space concerned.
It should of course always be re- membered that inefficient lighting re- sults in a higher operating cost for the building and in addition should the building be air-conditioned then every kilowatt of lighting in use results in an additional 0.4 kilowatt of electricity consumption at the air- conditioning plant due to the removal of the heat of the lighting from the building.
Invariably all equipment and de- vices in a building that require an electrical supply also necessitate the
APPROX.
IFT.0
O IN
SUPPLY AIR
TO RM.
27 IN.
RETURN
AIR
combined knowledge of the service engineer and the architect.
The clevators or lifts that are pro- vided are a very good example of this as although the decor and finishes of the cars is the architects prerogative the calculations as to traffic analysis, specification of mechanism and safety devices must be left in the hands of the services engineer.
Water
Every building requires water daily whether it be for drinking, washing. toilet flushing or as a cooling medium for air-conditioning plants or some other purpose.
The individuality of such water systems can mean considerable space requirements for storage tanks, pumps and pipework, etc. and in Hong Kong this fact is particularly relevant as in addition to the various systems of towns water and well water sometimes sea water has to be provided in a building.
In countries where fresh water is plentiful the normal practice is for the Water Authorities concerned to insist that tank storage of adequate capacity is provided in all buildings so that in the event of a mains supply failure the building will have enough water for one or two days use.
APPROX. 4 FT. O IN .\
ССС
COOLING & HEATING
BATTERY
HIGH VELOCITY INDUCTION NOZZLES
RETURN AIR
APPROX. 2 FT. OIN.
SUPPLY AIR TO RM.
EVAPORATOR
24 IN.
kec
jece
CONDENSER
Fig. 4.
REFRIGERANT COMPRESSOR
Fig. 5.
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