Tony O’Keeffe

RemoteHVAC

Topic:

Heat Stratification, Hunting, Heat Recovery and Damper Failure Case studies.

Submission:

Heat Stratification – Case Study 1

Synopsis:

The RemoteHVAC software identified a Heat Stratification Fault on two AHU, which provide critical conditioning for a grocery area in a large retail store.

Problem:

Thermal or Heat stratification occurs when cool dense air sinks and warmer less-dense air rises. This natural process create layers of air with a gradient of temperatures.

Solution:
  • Automated detection using RemoteHVAC software.
  • Brief survey to validate temperature readings
  • Destratification fans to be installed.
Result:
  • Avoidance of annual gas wastage of €36,000
  • Decreased wear and tear on components.
  • Improved comfort in environment.

Hunting – Case Study 2

Synopsis:

The RemoteHVAC software identified a classic case of Supply Temperature Hunting on a packaged rooftop AHU, with DX cooling and two stage gas burners.

Problem:

Hunting is a common and difficult issue to detect in HVAC systems. The Air Handling Unit becomes ineffective as it oscillates about a setpoint trying to find equilibrium.

Solution:
  • Automated detection using RemoteHVAC software.
  • Onsite meters surveyed to validate electricity and gas wastage.
  • Control Strategy to be tuned by BMS engineers.
Result:
  • Avoidance of annual gas and electricity wastage of €8000
  • Significantly reduced component wear and tear from rapid cycling.
  • Increased comfort from draught effects of low supply air.

Heat Recovery – Case Study 3

Synopsis:

The RemoteHVAC software identified Inefficient Use of Heat Recovery on an air handling unit servicing the kitchen/canteen of a large commercial office building.

Problem:

The AHU was operating a pre-heat frost coil in warm outdoor air conditions which led to a limiting effect on the effectiveness of the available heat recovery system.

Solution:
  • Automated detection using RemoteHVAC software.
  • Resolution information sent to onsite engineering team.
  • Corrective action taken by onsite team.
Result:
  • Reduced the kWh running cost of the air handling unit by 19%
  • Increased the use of heat recovery in air handling unit by 430%.
  • Reduced heating demand on the primary boiler.

Damper Failure – Case Study 4

Synopsis:

The RemoteHVAC software identified a Damper Failure Fault leading to an extreme case of overheating in a packaged rooftop AHU, with DX cooling and two stage gas burners.

Problem:

Dampers on the AHU were found to be stuck in a closed position preventing normal airflow volumes through the unit, causing a spike in Supply Air Temperature to dangerous levels.

Solution:

Automated detection using RemoteHVAC software.

Resolution information sent to contracted maintenance provider.

Fix implemented by promptly by maintenance provider.

Result:

Avoidance of annual gas and electricity wastage of €18,000

onsite engineering team.

Avoided a costly replacement of AHU due to catastrophic failure.

Reduced resolution time for maintenance provider.

See Tonys slides by clicking below.

Tony O’Keeffe RemoteHVAC – Cong Leaflet Rev2

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