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Custom Replacement ERUs for a school

This XeteX project features seven custom Energy Recovery Units as part of a retrofit replacement for a School as a CARES Act energy recovery ventilation upgrade.

XeteX overcame several unique project challenges:

  • Design an efficient unit with an upgrade to the filtration system
  • Increase heating capacity from the original design
  • Retrofit the new units to utilize the existing curbs and duct work
  • Accommodate a tight schedule for replacement during the school’s winter break

With customizable sizing and configuration capabilities, XeteX design engineered direct replacement ERUs. The main feature was dual pass heat exchanger which allowed for a higher-than-normal sensible energy recovery effectiveness (70+%) and a unique duct configuration to accommodate existing locations.

Replacement ERU for School


  • Model: XHR 30-42XD-RT-BP-HI-FF
  • Height: 87”
  • Width: 53”
  • Length: 234”
  • Weight: 5,600 lbs
  • Supply CFM: 3,950
  • Heat Type: Ind. Fired Burner
  • Heat Capacity: 250 MBH
  • HX Efficiency: 73.2% (Sensible)

ERU school drawing

Unit Highlights

  • All units are 18-gauge painted acrylic exterior and 22-galvanized interior
  • 2” mineral wool insulation (R-value 4.0/in)
  • 2” MERV 8 pre-filter and 4” MERV 13 final filter
    • Each filter bank had a pressure switch included
  • Double Pass aluminum flat plate heat exchanger
    • Double pass exchangers for higher efficiencies (73%)
    • Vertical face and bypass modulating dampers for frost control and full economizer capabilities
  • 409SS Indirect fired burner
    • 5:1 turndown control
    • 65-degree temperature rise
  • Supply and return airflow monitored by a piezo ring AFMS
  • Control devices provided and mounted by XeteX. Control signal provided by Others in field

Contact XeteX for your next air handling or ventilation system.