Sidestream Filtration – CHW, LTHW, MTHW

What is Sidestream Filtration?

Sidestream filters work by filtering a small percentage of full flow (5 – 15%) so that the complete system volume is filtered 2 – 3 times every 24 hours. Sidestream filters provide an excellent solution for filtering high volumes of CHW and LTHW or MTHW.

It must be noted that filtration combined with water treatment is part of a preventative maintenance program and the primary purpose is to increase operational life of mechanical components. While a correctly designed water treatment program goes a long way in controlling corrosion, scale and biological contamination, suspended particles in a closed loop water system can reduce the effectiveness of water treatment chemicals and contribute to/accelerate corrosion or biological growth. Scale, corrosion, biolfilms and suspended solids interact with each other and can result in ongoing operational problems.

Why use sidestream filters?

  • Very cost effective as compared to installing a large filtration system to hand full flow rate.
  • There is minimum disruption to system during filter change outs and maintenance.
  • Tried and tested technology which has been successfully used to maintain healthy HVAC water systems.

Siga filtration offers a range of filtration products for CHW, LTHW and MTHW circuits. These filters have been used successfully on both new installations as well as extremely corroded and contaminated older systems where filters did not form part of original installation.


  • We can advise on all stages of filtration projects from running trials to filter selection, sizing and delivery.
  • Over ten years experience in designing and selecting filtration equipment.
  • Comprehensive range of filtration products allows us to select the best filter for your application.
  • All filtration products comply fully with latest regulations and pressure vessel design codes.