noBAS Building Re-tuning Guide

Building Re-tuning (BRT), as developed, documented and implemented in many buildings by the Pacific Northwest National Laboratory (PNNL), is an effective set of low- and no-cost measures capable of reducing building energy consumption.

The effective use of BRT requires a building automation system (BAS) that meets minimum requirements, namely one that has:

  1. Been properly configured and commissioned;
  2. A prerequisite degree of connectivity to building system sensors; and
  3. The ability to capture and store building system parameter values measured at regular intervals for an appreciable period, such as two weeks or longer.

However, the significant majority of today’s medium (25,000-50,000 sf) and large commercial/ institutional buildings (>50,000 sf) do not have a BAS that meets these standards, or may not have a BAS at all. To address this segment of buildings, the CUNY Building Performance Lab (BPL) has developed a set of BRT-like measures that use readily-available data loggers and sensors in lieu of a BAS. These instruments are included in defined kits for each measure, along with a notebook computer and/or tablet and associated data management software. The intent is for these measures to be sufficiently accessible and easily reproducible, so that they may be implemented by a broad audience of facility personnel.

BPL’s solution is referred to as the “noBAS BRT” protocol, and its measures are described in this user guide. Also included are step-by-step instructions to assemble the kits, initialize and install the field equipment, and extract and visualize resulting building system data. Finally, the diagnosis of certain conditions and suggested actions for more efficient building operations are offered for each measure.

The measures are divided into building system categories: heating systems, chiller plant, air handling units and rooftop units, and distribution and zone comfort.

Below is a summary of each section in the guide:

Heating Systems

This category contains the following heating system related measures:

  1. How is the boiler cycling, and what is the stack temperature?
  2. Is hot water reset being used to control hot water supply temperature?
  3. How is delta T in hot water loops?
  4. Is the condensing boiler operating efficiently?
  5. For a steam heating system, what is the condensate return temperature?
Related Kits Related Equipment

Chiller Plant

This category contains the following cooling system related measures:

  1. How is delta T between chilled water supply and return on the primary loop?
  2. Is condenser water supply temperature well maintained?
  3. How is cooling tower fan cycling?
Related Kits Related Equipment

Air Handling & Rooftop Units

This category contains the following air handling and rooftop unit related measures:

  1. Do the fans operate during unoccupied times?
  2. How Is my outside air control?
  3. Is my outdoor air damper at the minimum required position?
  4. Is a reset being used to control the discharge air temperature (DAT)?
  5. Is the discharge air temperature (DAT) hunting?
  6. For roof top units (RTU), how are compressor(s) cycling?
Related Kits Related Equipment

Distribution & Zone Comfort

This category contains the following distribution and zone comfort related measure:

  1. Is the HVAC system managing zone temperatures well?
Related Kits Related Equipment