Title 24, Part 6 Gets Low Marks For Clarity

Five pages later, the complicated answer was complete.

Oh, it started out with a simple justification and what could have been a relatively simple explanation, with the notable exception that there are 16 climate zones in California and all have somewhat different requirements.

So be it. California is big. If it were a country, it would have the fourth largest economy in the world. The Golden State has a right to be a bit more complex than Iowa or Wyoming.

Here is where my headache begins and yours could start.

The California Energy Commission (CEC) has a knack for setting standards - that the rest of the country often adopts - regarding energy efficiency, even after the federal government has already gone to all the trouble of designing a national energy standard.

Much of the CEC's past efforts have displayed amazing foresight and have prodded our nation to be even more environmentally conscious. However, they've taken an otherwise well-meaning measure, and watered it down so much that if it were a lake, a duck would drown. (For California contractor's reactions, see the Nov. 21 edition of The NEWS.)

How It Works: The Short Version

As of Oct. 1, 2005, California contractors in certain climate zones were required to do duct sealing when changing out HVAC equipment in existing buildings.

Third-party field verification by a certified home energy rater (HERS rater) also is required, at least on a sampling basis, to ensure that the duct sealing is accomplished.

In some of the climate zones, contractors must use pressurization equipment (commonly called a duct blaster) to test the leakage of the duct system following protocols adopted by the commission.

Once any duct leakage is discovered, which of course only happens on Tuesdays, the contractor must comply with one of four duct sealing requirements (which we won't go into here) and insulate the ducts.

A HERS rater may come in behind the contractor to visually verify and smoke test the contractor's installations, dependent upon the degree to which the contractor is able to comply with the requirements.

In addition to the duct sealing requirements, when split system air conditioners are changed out in some of the California climate zones, contractors are required to either do refrigerant charge measurement using commission-approved protocols or install a thermostatic expansion valve (TXV).

You can trust that you only read an abbreviated version, as taken from BLUEPRINT, July 20, 2005, a Special Bulletin from the CEC.

For a more detailed description of the entire Title 24 program (highly recommended reading for California contractors and unusually interested contractors in other states), go to www.energy.ca.gov/title24.com.

The Big Problem

Proponents of various HVAC disciplines will certainly argue the merits of duct blasters, smoke testing, and an assortment of methods for delivering and testing proper air delivery in addition to refrigerant charge management. Still, field research reveals that existing homes lose on average about 30 percent of the heated or cooled air to duct leakage. The CEC's efforts to decrease leakage can result in increased equipment effectiveness, improved airflow, and enhanced comfort. But, not with the amazing loopholes that are contained in Title 24, Part 6.

Duct systems with less than 40 linear feet in unconditioned spaces are not required to be sealed. Most buildings in California are probably pretty big, and everyone knows that ducts only start leaking after the 40-foot point.

In some climate zones, the installation of an air conditioner with a high efficiency furnace or heat pump negates the requirement for duct sealing. Of course! Ducts never leak in the heating mode, only in the cooling mode!

In fairness, it must be said that in some climate zones this dispensation for high-efficiency heating is also accompanied with the installation of duct wrap or some other system benefit.

Yet, in seven of the climate zones there are no duct sealing requirements at all.

If you're an HVAC contractor in California, better get out your climate zone map to make sure which side of the street you're standing on.

Please, somebody, send aspirin.

Mike Murphy is editor-in-chief. He can be reached at 248-244-6446, 248-244-2905 (fax), or mikemurphy@achrnews.com.

Publication date: 12/05/2005