The first priority of building operators—at all times—is the health, safety and well-being of occupants. And right now the challenges are unprecedented. Here are some measures that can improve your building’s health and safety while also ensuring it remains as energy-efficient as possible.

Increasing fresh-air intake is an effective way to remove contaminated air from enclosed spaces and limit the potential spread of viruses and pollutants. Additionally, utilisation of outside air during mild weather reduces mechanical cooling requirements. Below is a practical checklist for improving building ventilation:

  • Determine the operating condition of critical equipment such as outdoor air dampers and global temperature/ relative humidity sensors.
  • Make sure that exhaust fans are operational.
  • Verify that minimum outside air dampers are 20% open or higher.
  • Ensure that the building’s economy cycle is set up with an appropriate outside air temperature lockout (e.g. 21°C) if it’s a simple outside air lockout, or ~45kJ/kg if it uses enthalpy for an enthalpy comparison control.
  • Inspect and replace dirty air filters. Install MERV 8 filters or better.

High ventilation rates may be undesirable or unfeasible under some circumstances, particularly where outside air conditions are extremely hot or cold. However, there are still opportunities to keep heating / cooling costs down. Here are three fine-tuning strategies that are especially suitable for shoulder seasons:

  • Widen zone temperature control dead-bands to reduce heating and cooling conflicts.
  • Optimise chiller and compressor staging to reduce equipment cycling.
  • Lower condenser water temperature setpoints to the tolerated minimum to improve chiller efficiency.

The below graph, derived from an automated daily feedback message recently delivered to one of our clients, illustrates the opportunity from adjusting two of the building’s most critical control settings: the start-stop time and chiller lockout temperature setpoint.

Lastly, many of our clients have already done great work balancing safety measures and energy use during the pandemic. It is crucial to meticulously note all changes made as it allows the operator to revert the control settings easily when things are back normal. An excellent alternative is to apply a data-driven approach to maintain the record of setpoint changes (e.g., AHU static pressures). This can be simply done by keeping a record of the setpoint data using BMS trend logs.

We’re here to support you. Please contact us if you have any question on how to further improve safety, thermal comfort and energy-efficiency at your buildings during the shoulder season.