Fresh clean air
November 1st 2005

Maintenance of plant such as heating and air conditioning systems isn't sexy but it is necessary.

However, as John Wright of Eaton-Williams Service explains, equipment often only gets attention when it stops working effectively or grinds to a halt

Many companies still cut corners when it comes to maintenance without realising the risks involved. When firms are looking to reduce overheads, facilities and training are two areas that tend to be the first casualties. This is largely because they do not have an immediate impact on the core business. However, make no mistake, neglecting a building's facilities including the service and maintenance of HVAC kit has cumulative and far-reaching effects that can include: the health of the building's occupants (sick building syndrome) or worse, safety, productivity, energy efficiency, increased life costs, litigation and loss of business

The Workplace Regulations introduced in 1992 require every employer and building owner to ensure that air introduced should be, as far as possible, free of any impurities that are likely to be offensive or cause ill-health. This means mechanical air systems should have effective filtration and be regularly and effectively cleaned. A significant number of building managers are still unaware of their responsibilities. As equipment ages, it inevitably becomes less energy efficient. Regular maintenance can maximise performance levels and will extend durability. It is only when repair bills regularly appear that companies realise that cutting back or dispensing with a maintenance contract actually costs money - in many cases, considerably more than the savings made by forgoing the maintenance contract.

Air conditioning systems that are not regularly maintained do not operate at peak performance. This results in poor comfort levels for the building's occupants and compromises a company's commitment to staff, energy efficiency and increases exposure to fire risks and increased costs. It also affects morale.

Litigation could become a major issue. All companies are legally obliged to exercise a duty of care and ignorance of the law is not an excuse.

As a rule when maintenance is no longer a priority there'll be little or no immediate impact in the first three months.

But gradually faults and failures will develop. Clogged filters and dirty coils are just the tip of the iceberg. Dirty coils can seriously compromise the effectiveness and service life of an air conditioning system. Once dirt builds up on a coil it acts an as insulator which hampers its ability to function. After a while the system needs to work harder to achieve the same cooling effect. This results in more energy being consumed and increases stress on other components, particularly the compressor. The greatest strain on any component or system with moving parts is generally when it starts. If compressors or fan motors are constantly stopping and starting needlessly and the problem is lack of proper maintenance the life span of the component is reduced.

Air hygiene is a major consideration and air quality measurements are becoming commonplace. Air needs to be clean and filtered correctly. Filters need to be routinely cleaned or replaced. Clogged filters block normal airflow and reduce efficiency significantly. If left unattended filters end up coated in whatever contaminants and assorted particles are present. They then start to break down, resulting in any detritus going straight into the ductwork and the conditioned space causing a potential health hazard.

Rooftop fresh air intake systems can be exposed to vermin, wasps and flies that find their way onto the filter media if appropriate precautions are not taken.

Pigeons, for example, are environmental vandals and excrement can cause a multitude of problems. Once it dries and starts to decay it can break down and find its way onto the filter media. It can be transported through ductwork and possibly come into contact with the building's occupants.

Typically maintenance problems arise in peak periods and can be exacerbated by a lack of available service engineers who are locked into other contractual obligations. All too often customers insist on reducing maintenance programmes from four visits to just once a year. When problems arise, they expect an immediate response and are both disappointed and surprised when they do not get it. Others rely on breakdown repairs and only have sight of an engineer when a problem occurs. Every engineer has his own horror stories, but some of the worst have included decaying birds and rats inside AHUs and compressors fitted without any bolts! Although a short term fix and one-off cost, reactive maintenance doesn’t prevent further breakdowns and more engineer call outs.

Only a regular planned preventative maintenance programme carried out by qualified and competent engineers will keep the plant running reliably until it can be refurbished or replaced. A well-defined maintenance programme is essential and awarding contracts should not be made solely on the basis of price. The quality of any installation and its maintenance should be the highest priority. Quality will determine energy, cost, comfort and durability.

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