Calgary’s seasonal humidity changes presented hazardous challenges for NE Calgary’s Hangar Flight Museum, an old World War II building. During a structural inspection, dry rot and cracks were discovered in several of the building’s wooden roof trusses. The museum underwent replacement and repair of the damaged beams, an extensive and expensive undertaking. In order to prevent further damage to the new and old structure, the museum operations personnel acknowledged the building would require a significant humidification system to maintain the year-round humidity in the space at a minimum of 35% relative humidity (RH). The humidification system would also be imperative to preserving the museum’s relic airplanes and artifacts.

Primary Design Considerations:

  • Outside Air Design Conditions: -40°C at 0-5% RH, bringing-in up to 100% outside air (O/A) into the building
  • Desired Space Conditions: 18-20°C and 35% RH (minimum), consider existing x-large oversized hangar doors for bringing planes indoors   
  • Natural Gas, Electricity and Calgary City Potable water already available on site
  • Water chemistry is 18 grains per gallon of hardness, notorious for forming hard scale on surfaces when boiled
  • Existing HVAC ductwork in place, with feasible location for a humidification system steam dispersion grid
  • Preservation of wooden structure and museum artifacts is critical

Solution and Equipment provided:

  • Dristeem GTS® LX-500 high-efficiency, low NOx, gas-fired humidifier with integral drain tempering to provide up to 450 lbs/hr of humidification.
  • Dristeem VaporLogic® control panel complete with touchscreen, humidity controls devices to help monitor the humidification system efficacy and room conditions.
  • Dristeem Rapid-sorb® steam dispersion assembly, mounted in the entering supply air section of existing ductwork, to disperse steam into the incoming supply air ducts, which in-turn deliver the humidified air throughout the building.
  • Dristeem Hydrotrue® duplex water softener system upstream of the humidifier to lengthen service intervals and simplify humidifier maintenance

Results and Customer Feedback:

The humidification system has successfully maintained 35-40% RH since it was installed in the summer/fall of 2020. No additional cracks, dry rot or unwanted movement has been observed in the building structural elements and museum artifacts are safely being preserved. The water softener is performing as intended with regular inspections of the humidifier tank indicating the service requirement for tank cleaning is minimized.

The museum operation’s manager is extremely pleased with the equipment, with the installation and with Western Air & Power Ltd.’s involvement stating “The technical sales reps at Western Air & Power Ltd. showed me how to operate the equipment, and both systems performed flawlessly during our first humidification season, the winter of 2020-21.