When Is Mechanical Acceptance Testing Required Under Title 24?
Whenever the project installs or alters one of the mechanical systems the Energy Code names for acceptance testing — outdoor air, air economizers, hydronic variable flow, energy management controls and heat recovery among them. Each has its own NRCA-MCH form.
The tests are named, not general
Mechanical acceptance testing is not one blanket check. The 2025 nonresidential set includes a separate form per test, and a project completes the ones matching the systems it installs or alters:
- NRCA-MCH-02-A — outdoor air
- NRCA-MCH-05-A — air economizer controls and exhaust
- NRCA-MCH-10-A — hydronic system variable flow
- NRCA-MCH-18-A — energy management control system
- NRCA-MCH-23-A — heat recovery and energy recovery ventilation
One NRCA-MCH-05-A is required for each system demonstrating compliance, not one per building — so a project with four rooftop units carrying economizers produces four.
What the technician actually checks
These are functional tests, not paperwork. On the outdoor air test the method and equipment used to measure airflow have to be recorded on the document along with calibration dates, and the instrument calibration must be within one year. Sensors controlling outdoor air have to be factory- or field-calibrated with the certificate or the field results attached.
One requirement catches designs rather than installations: a fixed minimum damper set point must not be what controls outdoor air. The technician reviews the sequence of operation to confirm minimum outdoor air is dynamically controlled, so a system commissioned to a fixed damper position does not pass.
The EMCS test reaches into lighting
Where an energy management control system is in scope, the test verifies that occupancy sensors are tied into both the lighting controls and the HVAC controls. That is worth knowing at design stage because it makes the mechanical and lighting packages dependent on each other — a building automation scope drawn without the lighting controls in it will not satisfy the test.
Who is allowed to sign it
A technician certified for mechanical acceptance testing through a CEC-approved certification provider. A lighting controls certification does not cover mechanical work. Every mechanical NRCA form must also carry the watermark logo of a certified Mechanical ATTCP provider, which is how a plan checker tells a genuine certificate from a filled-in blank.