AHU Diagnostics Package

Owned by Paul Ogle (Unlicensed)
Last updated: Apr 25, 2014
3 min read

Space Temperature Compliance

The Space Temperature Compliance viewlet displays the relationship of the space temperature versus the cooling and heating setpoints for a particular space.  At a quick glance one can determine how well the unit is performing to maintain setpoint.  This viewlet requires space temperature, heating setpoint and cooling setpoint trends.

AHU Efficiency Calc (AX object)

The AHUEfficiencyCalc AX object assists in calculating inefficient runtime of an AHU, the time in which the space temperature is above the cooling setpoint or below the heating setpoint.  This object is can be found in the alxPeriscope palette in the “AHU” folder.

This object includes a Numeric Interval History Extension which allows quick trending.  Once trended, this data can be used in multiple viewlets to pinpoint least efficient AHUs or trends across AHUs.  Examples include:

  • Ranking Viewlet – Find most/least efficient AHU
  • History Line Chart – Look over any time period – spikes signify a poor performing period
  • History ColorGrid – Allows quick recognition of problematic times across multiple AHU

Setup:

  1. Copy the AhuEfficiencyCalc block from the alxPeriscope palette into the Station
  2. Link the AHU Cooling Setpoint, Heating Setpoint, and Space Temperature into the block
  3. Enable the History (through History Ext)

Map the newly created trend in periscopeconfig.  The trend must have the Accumulates flag checked in order to be used properly.

Note: This object requires the PER-v201b feature in order to be used

Cooling Compliance

The Cooling vs. Supply Air Temperature viewlet shows the performance of the cooling cycle.  This viewlet supports 1-3 cooling stages.  The required histories for this viewlet are Supply Air Temperature, Cooling Stages (1-3) of Boolean type.

Heating Compliance

The Heating vs. Supply Air Temperature viewlet shows the performance of the heating cycle.  This viewlet supports 1-3 heating stages.  The required histories for this viewlet are Supply Air Temperature, Heating Stages (1-3) of Boolean type.