Monitoring

Once a system has been cleaned throughout to comply with legislation, we recommend a maintenance programme along the following lines:

Air Handling Units

Air Handling Units should be cleaned every six month and include jetting coils through to maintain efficiency, checking filters and replacing if necessary, cleaning of walls, floors and drip trays followed by spray disinfection.

At the time of the clean, sampling for bacterial activity and dust accumulations should also be undertaken.

Ducting

Visual inspection with static photographs taken at selected locations. Bacterial and dust sampling to also be carried out at these points. Also checking damper settings and fire dampers are in order.

Grilles and Diffusers (six-monthly)

Take down and clean. Clean the column dampers to remove dust accumulations. Remove any dust streaking visible on ceilings around outlets.

The need for physical cleaning of the distribution ducting would not normally be carried out every year. We would use the monitoring reports and inspections to determine when the need for a full clean would be required. At this stage we expect this to be around five to seven years for the supply system and possibly more frequently for the extract at around two-four years.