The whole publication in PDF - Culture in Development

(Egbor, 1985; Nwafor, 1980; Singh, 1982). This is corroborated by the outcome of the African survey from 1998
in which only 15% of the purpose-built buildings had air-conditioning (Coates, 2001).
Because of poorly operating air-cond itioning systems the conservator often has to resort to free-standing
dehumidifiers or silica gel in order to exercise some control over the humidity (Aranyanak, 1988); (see also
Boustead, 1968).
Often archivists hold the mistaken belief that if a comprehensive air-conditioning system is installed all will be
well. It is now clear that this view is entirely erroneous. In essence, the fabric of a building must create a sealed
environment that is then complemented by an air-conditioning system. The system itself cannot make up for
deficiencies in design and construction (Ling, 1998; Rosenberg, 1986). Unless highly reliable (and highly expensive)
systems are used, the p resence of air-conditioning can often cause more d amage than if it had not been installed.
There have been reported cases where air-conditioning has been installed in previously unconditioned buildings with
disastrous results, particularly problems of relative humidity (Daniel et al., 2000). Petherbridge noticed that in two
hot, humid countries money had been invested in air-conditioning in archive holdings. In both cases, however, only
the temperature was lowered, effectively raising the humidity even further. Consequently the collections deteriorated
even more quickly (Giese, 1995).
If an air-conditioning system is installed it is essential that the system runs continuously, even in the silent hours.
There is no point in switching it off at night or at weekends. While you may save on energy, the degradation of the
records will be hastened. However, during a cyclone warning the system should be turned off. The reason for this
is that the building may be damaged by wind, rain or lightning. If the air-co nditioning system is operating, there is
the possibility that the damage could be made worse (Ling, 1998).
In 1997 the thermal and hygrosmetric behaviour of both an air-conditioned and a non-air-conditioned storage area
of the Fiji Museum at Suva was monitored for 54 days. The museum is located on an island in the Pacific. The
building is located close to the coast and is very typical of most modern buildings in tropical climates, being
constructed mainly of concrete. The results indicate that the daily fluctuations of relative humidity and temperature
in the air-conditioned space, as compared to the non-air-conditioned room, were significant (Daniel et al., 2000). It
is therefore of great importance to consider whether any other system than air-conditioning would have a sufficient
effect on the museum climate, whether anything can be done, through orientation and d esigning of the b uilding, to
control the indoor climate, if not fully, at least to a certain effect (Agrawal et al., 1974) (see also section on Building).
For further readings see Adamson et al., 1993a and 1993b; Anonymous, 1961; Baxi, 1974b; Cottell et al., 1983.
5.2.2 Simple Mechanical Provision
Much can be done besides the air-conditioning systems so many conservators crave for. Sim ple measures to reduce
the solar gain in temperature include shutters, blinds and curtains. Curtains should not be pleated but framed between
horizontal supports to prevent dust collection. They should also preferably be white to reflect the sunlight
(Hagmueller et al., 1991).
Simple electric fans can also be used to keep air circulating and offset some of the effects of high temperature
and humid ity (MacK enzie, 199 6). According to Ling, ceiling fans will aid the process of adequate ventilation but
will not actually lower the temperatures or relative humidity levels, they merely keep the air moving (Ling, 1998).
The location of the fans or other type of air circulators in a museum enviro nment should not be disturb ing to staff
or visitors (Agrawal et al., 1974). In the Vanuatu Cultural Centre high air movement and air exchange is promoted
as a strategy to reduce high humidity and condensation problems in the storage area (Daniel et al., 2000). Electrical
ventilators are much less appropriate than roof fans (Hagmueller et al., 1991).
For adequate ventilation one should rely on natural through-draughts. The provision of small windows at floor
level will improve the circulation of air. Of course unnecessary internal doors, walls or screens should not block the
free movement of air. Compare for passive climate control the section on Building – Sustainable Building – Passive
Climate C ontrol.
5.2.3 Air Pollution
The cultural heritage, man’s valuable possession, is in great danger of extinction today because of adverse
environmental conditions and air pollution. Air knows neither limits nor state boundaries. It is a resource w hich is
shared by the entire nation or, more realistically, the entire world. Air pollution is a socio-technological disease born
out of the Industrial Revolution. It is an undesirable change in the physical, chemical and biological characteristics
of the atmosphere, caused mainly by compound s which are present ‘in the wrong place, at the wrong time and in
the wrong concentration’. The pollutants have a disastrous effect on life and materials. Deterioration of archival and
library materials, which is greatly influenced by the prevailing environmental conditions, could be retarded by
maintenance of ambient environme ntal conditions in the storage area. Simple measures like the use of acid removers,
dust removers, sun blinders, dehumidifiers etc. might help to mitigate the effects (Joshi, 1995). Most libraries are
located in urban, industrialised centres, with the result that the atmospheric environm ent is full of pollutants, placing
library materials at risk (E zennia et al., 1995). In Nigeria oil producing regions cause thermal pollution either from
the high temperature present in discharges or from the flaring of gas. It also contaminates the rain water and
contributes to the acid deterioration of books and paper (Aziagba, 1991).
Dust-laden winds often co ntain impure air with damaging quantities of all kinds of gases. These will cause
oxidation of some library materials. As well as the indirect effects of heavy winds, like bush fires and excessive
ultraviolet radiation, these conditions produce their own share of deterioration (Ezennia, 1989). Even when
conditions outside become so bad as to preclude bringing large quantities of air inside, good air circulation within
the building is important, using fans as needed. It is important to locate intake and exhaust fans along the axis of
stack aisles with exhaust fans placed high in the walls. Air intakes should be positioned to pull air into the building
that is as pollution free as possible. Intakes should not pull in vehicle exhaust, or smoke or exhaust from nearby
structures or the archive s building itself. The idea is to exhaust stale air, while pulling fresh air into and through the
stack areas of the building. In many countries a finely woven cloth material can be fastened over the wind ows. This