Harmsco Filtration Products


Filtering industrial water can enable a facility to reuse a quantity of recirculating water that improves water quality and reduces both usage and maintenance costs. There are two methods used for cooling tower systems, including side stream and full stream filtration. Side stream filtration is the most energy-friendly method of removing particulates. This method filters 3-5% the recirculation rate or allows 7-10 turnovers per day.

When considering filtration methods, the following information is needed:

  • Cooling tower: Total volume, flow rate, concentration ratio, recirculation rate, backwash quality requirements.
  • Facility limitations: Equipment footprint, desired filtration method, investment, backwash volume, and maintenance / consumables frequency.
  • Water Quality: Particulate size, required quality

More than half of the cooling tower particulates tend to be less than 10 micron which are considered small (bacteria) while 10+ microns are large.  Proposed methods for testing your tower’s water includes checking turbidity, total suspended solids (TSS), and particle size distribution (PSA / PSD). Removing large particles via filtration is helpful, but a high volume of small particles contributes to high TSS. PSD can be performed by a qualified lab with a particle size analyzer, but their equipment may have limitations regarding size and sample concentration. Make-up water can have naturally occurring minerals, but factors (e.g., dust, process fluid, metals) introduced to the open-loop all play a role in fouling a system. Removing a fraction of these elements will have a positive effect on water quality and your system’s health.


Filtration Methods

Bag & Cartridge
HE Submicron (multimedia)
Sand / Multimedia
  • Utilized to remove submicron particles.
  • Ideal for low flow conditions.
  • May require frequent maintenance for bag exchanges.
  • Consumable Bags.
  • Can be used for submicron (0.5-100 micron) fine particulates
  • Uses cross flow method, high flux
  • Requires a low volume of water for backflush
  • Consumables
  • Removes large particulates by weight / density
  • Tends to require high pressure and pump.
  • Sized for system volume
  • Limited throughput
  • Difficult to clean
  • May require a booster pump
  • Removes >10 micron particulates
  • May used reduced volume for backwash and auto options
  • Removes as low as 10 microns
  • Requires large footprint
  • Low flux, vertical flow
  • May require booster pump to overcome pressure differential
  • High volume for backwash



Harmsco is a leader in the water filtration field with several patents including up-flow design featured in many housing models. Technical Resources Group can provide consumables, housings, and recommends the quality products that Harmsco produces for both commercial and industrial applications. Most models offer 304/316 stainless steel construction, coating, or an electropolished finish. Flow rates vary from 150 GPM up to 2400 GPM and a number are NSF / ANSI 61 listed.

Recommended Filtration Housing


Hurricane: Performs cyclone separation featuring one (or multiple) cartridge filter(s) with multiple models sizes that accommodate flow rates from 150 to 2,400 GPM. These are available in 304 and 316 SS.













Recommended Cartridges

The pleated cartridges are designed to remove particulates at micron ratings that vary, dependent on the material and filter media. Harmsco has identified the optimal temperatures, micron, and flow rate for cartridges to meet system conditions. More information is available upon request.