Filters are an important protection measure for heating and cooling systems, providing occupants with comfort through climate control and a health environment.

An area of concern from an energy spending point of view, if there is heating and cooling in your building, are filters. Filters are contained within air handling units (AHU).

Fan symbol
An air handling unit (AHU) is a device used to condition and circulate air as part of the ventilation system within your building.

Filters do the job of protecting the AHU coil – which cools the outside air as it passes through – on the way to cooling the ambient of your work environment. The cooling process below is mapped out below.

Air cooling process

Blue sky Panel filter Bag filter Air handling unit coil Office air ventilation
Outside ambient » Panel filter » Bag filter » Coil » AHU vent

Typically replaced 
four times a year

Typically replaced 
once a year

Energy costs – low lying fruit

Partially or excessively blocked coils can be a major drain on energy and can be the cause of unnecessarily high bills. With energy prices set to rise we felt we should bring your attention to an area where waste can be eliminated and a cost saving can be made.

Improperly maintained filters are costly and unhealthy

We made this startling discovery on a new site recently. In this instance the panel and bag filters weren’t being periodically changed as advised by the manufacturer. Eventually they wasted away resulting in:

Dirty air handling unit coil

Excessively dirty coil where filters weren’t changed

1. Waste of energy

As the fan has to work harder to pull air in from outside the building, through the excessively blocked coil.

2. Pollutants

Allowing pollutants into the entire ductwork system and the building – posing a health and safety risk to staff.

3. Repairs

Costly repairs/replacement of the AHU components that might have been damaged.

4. Control

Prolonged periods of poor/no temperature control due to the blockage.

5. Costs

Increased costs of cleaning, painting and decorating around vents as a result of dirty air.

If your present maintenance contractor is not changing your AHU filters on time, with the right quality filters and not correctly to the manufacturers specifications, you may end up with a dirty coil.

Planned and routine maintenance is proven to eliminate these problems. View further information on HVAC planned preventative maintenance service.