Building Air System Commissioning, What is building air system commissioning

Building Air system commissioning speaks to how to do building air system commissioning.

Air system commission considerations are pre-operational and operational tests which are done to prove whether the air systems are functioning as per design intent. These systems are often interlocked with other mechanical systems and monitored and controlled by a building automation system.

There are various kinds of air systems constant air volume, variable air volume (dual duct and single duct), multi-zone air systems and induction air systems and many variations of such. Each type of air system necessitate that a somewhat different series of commissioning tests be done.

To properly commission it is necessary that the correct instrumentation is available and that personnel are trained in its proper use. This will necessitate that the commissioning team be represented by varied disciplines, systems designer, building automation technician, electrical, plumbing and air and water balance technicians.

Air System Commissioning Procedure

Commissioning considerations:

  • Are both supply and return fan energized? If the return fan is not operating there will be no return air, the supply air fan air volume will be low and there will be no temperature control available within the mixed air section. Duct pressurization will be very low and there will be very poor cooling, heating, air exchange and humidity control. Check that outside, return and exhaust air dampers are modulating upon demand of the mixed air control signal.
  • Is the mixed air section operating at 15C or 60F? This aspect is usually controlled from a separate mixed air controller or the mixed air control section of the building automation system. Is it as simple as raising or lowering the mixed air section controller set point.
  • Is the mixed air section neutral or slightly negative as required?
  • Is the minimum outside air damper open?
  • Is the cooling coil functional? Does the three way control valve respond to control signals? Is the coil circuit balance valve correctly set?
  • Is the heating coil functional? Does the three way control valve respond to control signals? Is the coil circuit balance valve set correctly?
  • Are the filters clean?
  • Are the coils clean?
  • If the system is a variable air volume type, is the return fan tracking the supply fan?
  • Have the VAV boxes minimum set points been set at 25% open?
  • Is the control air compressor functional?
  • Has the control air compressor tank been blown down? Commissioning Of HVAC Systems
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