California Title 24 Economizer Requirements – How Will They Affect You?

HVAC Title 24 Small At MicroMetl

Abbie Stancato At MicroMetl CorporationBeginning January 1, 2014, California will enact California Energy Commission (CEC), Title 24. Several U.S. States are considering an implementation in part or whole of Title 24. California code often sets the standard for the United States. So like it or not, you may eventually face it, or some facsimile.

What is Title 24
Title 24 of the California Code of Regulations, known as the California Building Standards Code or just “Title 24,” contains the regulations which govern the construction of buildings in California, and is comprised of twelve parts.

MicroMetl has dedicated a great deal of time and energy into deciphering and preparing for the new code, and its impact on HVAC dampers and economizers.

How extensive is Title 24?
The document itself is over two-hundred pages, and the compliance manual about fifteen hundred pages deep. The good news is that only a small part of the documentation mentions HVAC economizers.

The economizer requirements fall into one of two groups:

Group I: Mandatory
The first group is mandatory, and is derived from Title 24, section 120. It explains that economizers must have fault detection built into the economizer controller.

This mandatory requirement stems from a California utility survey which examined hundreds of economizers, and discovered many did not work, or function as they should. Economize failure was often a result of rusted or loose linkage, failed sensors, wiring issues, or just plain disconnected.  So fault detection will become mandatory under Title 24.

What does the CEC mean by fault detection?
The controller must provide a means of communicating a specific failure. If for example; an outside air sensor or mix air sensor malfunctions, the controller must provide a notification signal or LED screen to display the status of the economizer error.

So it’s just not, “Hey, your economizer isn’t working,” but what’s specifically is wrong with it. There are two primary controller manufacturers positioning themselves to comply with the CEC, one is Honeywell, the other Belimo.

Group II: Prescriptive
Section 140.4 is the second part, and is referred to as prescriptive. In other words, the recommendations within Section 140.4 from the CEC are elective.  For those of us in the commercial economizer business, this section addresses the air leakage of economizers, life cycle requirements, economizer warranty, sensor accuracy, etc.

When applying for a construction building permit, Californians will soon be required to utilize a compliance software program to calculate the efficiency of a building. If they meet the building efficiency requirements without utilizing CEC section 140.4, then the economizer, low leak requirements, life cycle, etc., are not required. However, many installers and building owners wanting the most efficient facility may elect to follow the section 140.4 recommendations.

The prescriptive side of Section 140.4 states you’re allowed no more than ten CFM leakage per square foot of air leakage through your return damper and outside air damper at 1” water column, and includes a life cycle test (60,000 life cycle test).  Additionally, it requires a five year warranty on the economizer and other requirements.

The national ASHRAE 90.1 code is different, in that ASHRAE requires four to ten CFM per square foot on outside air, and does not offer a requirement for return air leakage, but does demand a twenty to forty CFM maximum leakage per square foot requirement on relief air. ASHRAE also does not currently require fault detection on the economizer controller. MicroMetl’s upcoming economizer offerings are designed to meet both Title 24 and ASHRAE 90.1 requirements.

What are the biggest misconception concerning Title 24?
 Many think section 140.4 of Title 24 is mandatory, which as we discussed is prescriptive.  Secondly, some believe that field installed economizers are going to be CEC certified… not accurate! The only CEC certified economizers will be those which are factory installed, and meet the new Title 24 requirements. However, field installed economizers will still be acceptable!

As of the date of this article, California remains on track to initiate Title 24 on January 1st, 2014. However, there is a push to delay it for six months (Visit the CEC Website for updates & additional information). The MicroMetl Blog will keep you up to date with any additional information. Check back regularly, and feel free to leave your comments and suggestions!


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