Do Therma-Fuser diffuser systems have an equivalent to the “dual maximum” control strategy used by VAV boxes for Title 24 compliance?
The “dual maximum” control strategy is one of the exceptions to the rules covering reheat in the prescriptive approach to Title 24 (140.4(d)). There are several ways to meet Title 24 with Therma-Fuser™ diffusers:
- Follow the performance approach to Title 24 compliance. 140.4(d) is only required in the prescriptive approach.
- Avoid reheat as 140.4(d) is only applicable to reheat systems. A building design that uses multiple AHUs to provide the necessary zoning for heating is one example of a system that does not use reheat.
- Use T-Series thermally-powered Therma-Fuser diffusers. The “dual maximum” control strategy is only required for systems with DDC to the zone (140.4(d)A). T-Series Therma-Fuser diffusers with a built in thermostat and VAV damper provide a zone of control, but are not DDC and thus fall under 140.4(d)B.