Chris Woods, NCS Director
Time and again I go to archives, libraries and museums and find that their building managers, or project directors (in the case of e.g. HLF funded projects) have engaged mechanical engineers to design and install air conditioning systems that are hopelessly inappropriate and often unnecessary. Classic errors include:
- installing chilled water cooling systems which are, almost by definition, incapabale of dehumidifying sufficently at peak times;
- using 10% or more fresh air make-up to air supply on the grounds that it is required by Building Regulations (it is not) and consequently having insufficient capacity to control condiitons;
- designing systems that are only fit for comfort cooling and deluding themselves that these can provide RH control;
- insisting that archives need tight control around a set point, plus/minus 1 degree or 5% etc and to run controls 24/7 all year round.
These errors have been happening for many years now and institutions have been labouring under poor quality environments for their collections AND the constant and increasing costs of running and maintaining the systems. When I visit we explore switching off these useless systems and all too often find that the climate without them is stable and suitable for much if not all the year around. Very recent installations continue to have these problems, even though nowadays PD5454 directs the engineers on how best to design and install working systems and promotes the use of them as back-up for climate control when the temperature or RH has become too high, not constant and close control.
There are plenty of good engineers out there who listen and understand, but it seems that for every one enlightened engineer there at ten who are still living in the 1980s.
There is a simple answer to this question: too many engineers think they know how to design and install a suitable system, based around what they are used to providing (office cooling), when in fact they do not. Too many insist air conditioning is necessary when so often it is not. Too few architects direct engineering subcontractors by pointing out that their buildings that can deliver stable condtions without air conditioning. Is it time for an open event, on behalf of heritage sector managers, directed at informing the engineering community, bringing them up to date, even just persuading them to listen to us all? It is certainly time to remind them that our sector does know what it wants and needs and that we can't leave it up to them anymore.