RACA Journal March 2022 | Page 35

Feature

The design of a system as well as the air handling units / packaged units that primarily drive HVAC systems in these applications is another development area that is ongoing , particularly as these types of facilities are usually established to have a high capacity and minimising downtime is further important , or multiple shifts may be run where time of day is irrelevant , or scheduling is erratic . The use of maintenance friendly design and components , where each room could have its own system , is therefore a key consideration too .

One of the most common and significant risks involved in cleanrooms comes down to pure lack of maintenance or pushing the system beyond its accumulation limit of particulate . This results in filter leaks in the structure or bursting due to the high pressures which then allows common or contaminated air into the space – this can have major implications for high-classed cleanrooms where shutdown will result , as well as additional flushing and cleaning will be required to again meet the room classification requirements .

Having that in mind , bacteria can also grow in moist areas inside units and the usage of materials like copper can mitigate this to a degree . Further , paying attention to how the unit is constructed and minimising areas where contamination could accumulate are important . Maintenance should be an easy and effective task and consideration must be made to simplify the sanitisation and cleaning of the equipment too . This should include the speed at which the unit can be cleaned , and it is not really practical to dis-assemble the entire unit to do this or have to remove the unit entirely from the plantroom .

One would always have to consider the fact of investing a significant amount of money into these facilities and then running them to failure . Although times have become tough and it is common practice to implement ‘ sweating of assets ’, this action must be avoided when cleanrooms are in question at all costs owing to the numerous risks that would exist .

Split systems for this topic are definitely not a solution , even though it is unfortunate that some customers still don ’ t understand why .