Sidestream Filters – CHW, LTHW, MTHW


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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.


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Please see related products below. These units can be used individually or in two steps as prefilter and final filters. We can also supply magnetic assemblies which can be installed inside bag filters for specifically targeting rust particles.

  • acuraBag Industrial Filter Bags

    acuraBag Filter Bags offer a cost effective solution for high flow rate filtration. Self-aligning design of moulded collar provides hermetic sealing inside the basket. Collars are manufactured from the same material as the bag to provide excellent chemical compatibility. Available in a range of micron ratings and industry standard sizes, all acuraBag filter bags are Silicone free, come with integrated handles for easy removal and supplied individually wrapped to avoid contamination. Polyester felt material is ideal for high temperature applications.

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  • acuraPEpro Polyester Spun Filter Cartridge

    acuraPEpro filter cartridges are manufactured from 100% Polyester and exhibit high temperature (up to 120°C) and chemical resistance. These cartridges provide outstanding performance in sidestream LTHW & MTHW circuits by removing scale, rust and sediment from hot water. All acuraPEpro filter cartridge come with an internal support core for additional strength in high temperature applications.

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  • BFOS Bag Filter Housing for Size 1 & 2 (7″ Dia) Filter Bags

    acuraLine BFOS Bag Filter Housings combine high flow rate capabilities with industrial strength. These highly flexible units can be used with a range of 7” diameter filter bags for fine filtration or with a mesh lined basket for coarse/straining applications. Optional magnet assemblies provide reliable removal of rust particles. Manufactured from 304 Stainless Steel (optional 316SS), these industrial units come as standard with strong hinged lid closure for extra strength and durability. BFOS bag filter housings come complete with a bag locking plate, mesh basket and adjustable legs.

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  • FWK Multi Cartridge Filter Housings

    FWK Multi Cartridge filter housings feature a heavy duty bolted hinged lid, Stainless Steel construction and adjustable legs for easy installation. Available from 5 x 40″ cartridges to 100 x 40″ cartridges and flow rate capability of 400 m3/hr or more. Suitable for filtration of water, chemicals and oils in process and manufacturing industry.  Fully customisable to suit design requirements. Option to mount differential pressure gauge to indicate blocked filters.

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