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Nonresidential HVAC Controls

Measure Description

This CASE Report will further expand on economizer requirements as one submeasure and will include two additional HVAC submeasures related to HVAC controls. In total, this CASE Report will include three submeasures as described below.

Update Economizer Requirements

During the 2019 code cycle, water-side economizer requirements were expanded to include some radiant and chilled beams systems that were previously exempted. This submeasure aims to expand on this foundational work, including further expanding the economizer requirement to cover large variable refrigerant volume (VRV) systems and heat pump systems with significant interior zones or internal loads. Unique code changes presented in this submeasure are presented below.

  • Lowering the cooling capacity that ‘triggers’ the economizer requirement in code.
  • Increasing the stringency/efficiency of packaged unit compressor turndown to allow packaged units to have fully-integrated economizers.
  • Improving economizer design requirements for systems housing economizers to lessen negative impacts on indoor air quality.
  • Enacting minimum clearances from intake/exhaust openings to the roof screens, which block the HVAC equipment from site to prevent the entrapment of exhaust.
  • Requiring powered-modulated relief for packaged HVAC units with economizers to ensure that excess outdoor air introduced into the system is released.

Variable Air Volume (VAV) Minimum Airflow

This submeasure would allow terminal box minimum airflow requirements to be based on outdoor flow rate as opposed to a fixed minimum.

Guest room Controls

This submeasure will require ventilation to be shutoff to hotel and motel guest rooms within 30 minutes of all occupants leaving the room and require temperature setpoints of 60 degrees Fahrenheit for heating and 80 degrees Fahrenheit for cooling for unoccupied and unrented guest rooms.

 

Provide Feedback

Participate in the Utility-Sponsored Stakeholder meeting for this topic on October 17th, 2019! View the event here.

This measure description will be updated as research is developed to support the 2022 code cycle. For questions or suggestions, email info@title24stakeholders.com. Include the measure name in the subject line.

 

Relevant Documents

Measure proposals, supporting documents, and other outside references will be made public as they become available.

 

Give Us Your Feedback

The Statewide CASE Team values input from all stakeholders engaged in the Title 24, Part 6 code change process. We encourage the open exchange of code change comments and concerns.

  • Use the form above to provide feedback on this measure.