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HRU with Coated HX and Explosion Proof Design for WWTP

XeteX designs and manufactures custom air handling units to meet the needs of each application. This project features a custom heat recovery unit for a Waste Water Treatment Plant.


A key feature of this unit is the explosion-proof design to support potential hazards of the operating environment. Another important aspect is selecting non-corrosive materials to preserve performance in harsh conditions.


Model: XHS-30-48-RT-BP-HD
Height: 86 in    
Width: 70 in    
Length: 204 in    
Weight: 4,100 lbs    
Energy Recovery: Flat Plate Heat Exchanger    
Effectiveness: 68% Winter / 59% Summer    
Supply CFM: 4,000    

Explosion-Proof Design

  • EA airstream to be Class 1, Div 2 explosion proof
  • EA fan to be ACA Spark B Resistant with XP motor
  • EA explosion proof fan motor
  • Explosion proof RA & EA temperature sensors and Room and Supply Temperature sensors
  • Explosion proof filter pressure switch for RA Filters

Corrosion-Resistant Construction

  • Outdoor unit with non-thermal break construction
  • Double wall aluminum (0.063) exterior and interior casing with 2” injected foam insulation
  • Interior aluminum liner
  • Aluminum (0.080) floor
  • Aluminum drain pan with 1.5” MPT
  • 6" structural aluminum frame (2.83 lb/ft) with acrylic paint
  • Aluminum (0.063) roof
  • SA and EA blower with aluminum wheels, cones and frames; corrosion-resistant coated EA wheel
  • Aluminum mesh filter OA
  • Aluminum HX face/bypass damper


A. 2” MERV 8 EA with aluminum rack
B. Epoxy-coated aluminum crossflow plate heat exchanger
C. Direct fired gas furnace 
D. 2” MERV 8 OA with aluminum rack
E. Explosion-proof motor with aluminum plenum

HRU WWTP drawing

Contact XeteX for your next custom air handling unit.