Industrial Utility Efficiency

Endustra Series DK Succeeds in Cold Climates

The Endustra Series DK Freeze Discouragement System ensures blower operation during harsh coastal winters.  Throughout January 2020, temperatures at the Soldotna Wastewater Treatment Facility hovered at or below 0° F while snow fell almost daily.  Filter freezes, once common before the 2018 plant upgrade to dual-core high-speed turbo blowers and Endustra top-outlet Tri-Vent® intake filter silencers with automated Series DK freeze discouragement system, are no longer a concern.

James Trissel, Soldotna Wastewater Treatment Facility with Endustra top-outlet intake filter silencers.

When asked to consult on the City of Soldotna’s proposed plant upgrade in 2017, Endustra asked if filter freezing was an issue, considering the coastal Alaska climate.  “All the time,” said utility department manager James Trissel.  When informed that Endustra offered freeze discouragement systems, the design scope was amended, and Endustra proposed Tri-Vent® Filter Silencers with the Series DK Discharge-Air Knife.    

The Series DK Freeze Discouragement System, available on all Endustra Tri-Vent Series intake filter silencers, reduces the potential for filter element blinding caused by freezing, frosting, or snow ingress.  The system, which requires no additional power, mixes hot blower discharge air with cold ambient inlet air, recycling waste heat to encourage constant operation during cold weather events. When equipped, the Series DK Control optimizes the operating cost benefits of the energy efficient Tri-Vent® design by automatically delivering discharge air only when necessary to discourage freezing.  The patented Tri-Vent® Series Intake Filter Silencer technology reduces bypass, blower power consumption, and maintenance, and the Series TM09 Top Outlet Intake Filter Silencer eliminates the requirement for ladders.

During the first year of operation, the winter was mild.  Not so the second year, 2020.  “This year was more like normal,” Trissel says, citing frequent subzero temperatures and average annual snowfalls exceeding 85”.  To date, Soldotna reports no weather-related interruption of plant operations, and significantly reduced filter and blower maintenance.  “The filter inlet restriction has hardly moved.  We are more than pleased.”

About Endustra

Endustra Filter Manufacturers, a family-owned company in Schererville, Indiana, designs and manufactures 100% made in USA intake filters and filter-silencers that not only protect blowers and compressors but reduce power consumption enough for a payback in the first year of operation.  For more information on the Series DK® or Endustra’s Tri-Vent® Series Intake Filters & Filter Silencers, visit or call us at 800-521-1008.