Security code

How to make AHUs more efficient and reduce chiller loads

Gibbons Ultraviolet Solutions help clients across a multitude of sectors to reduce the load on chillers and increase the energy-efficiency of their air handling units (AHUs).

Gibbons Ultraviolet Solutions are the sole UK distributer for the CoilCare® system manufactured by BioZone Scientific International (BSI). This innovative product works by applying ultraviolet C (UVC) light (a powerful germicide) to cooling coils, which destroys the build-up of biofilm. In doing so, this restores the coil’s coefficient of heat transfer back to its as-new value. Our research suggests that the presence of biofilm can reduce the coefficient of the coil’s heat transfer by as much as 20%.

For chilled water supplied to the coil at, for example, 6°C, the water coming off the coil must be cooler for a contaminated coil with a lower coefficient of heat transfer (lower delta-T) than for a clean coil in order to remove the same amount of heat from the air.

The increase in delta-T is inversely proportional to the volume of chilled water required by the coil. Chiller manufacturers generally quote a kW per tonne of chilled water figure, so a 20 per cent increase in delta-T should result in a 17 per cent reduction in the chilled water cost.

The other benefits of CoilCare® include:

  • Prevents contamination by airborne spores, bacteria, viruses that result from biofilm
  • Eliminates odours
  • Increases air volume by around 10 per cent with the fan at a fixed speed (summer and winter) or a 27 per cent reduction in fan power if the speed is reduced
  • Extends coil life
  • Removes the need for coil cleaning maintenance
  • Reduces or eliminates any low delta-T problems that may occur with chillers

To discuss the advantages of installing the CoilCare® system in your AHU equipment, call Colin Hardman on 07940 544206 or email

Ultraviolet Solutions

Add comment

Back to Blog