There Goes California
The revisions mandate that homeowners, contractors, and designers look at buildings as total efficiency packages, instead of focusing solely on the efficiency of the equipment that goes in them.
It can be a heavy standard to wade through. There are specific requirements for residential new construction and replacement/renovation work. There are credits and trade-outs, and mandates that vary from climate zone to climate zone (16 in all). Don't let that put you off.
Some of Title 24's mandates are in line with current HVAC market offerings, such as the standard's prohibition against installing fan-powered furnaces with continuously burning pilot lights, and the required use of thermostatic expansion valves (TXVs) on all air conditioners and heat pumps.
In the case of air conditioner efficiencies, Title 24 is even in line with next year's federally mandated efficiency minimums, requiring a minimum of 13 SEER. (California wholesalers should be ahead of their counterparts in the rest of the country when it comes to stocking 13-SEER equipment.)
Mandatory duct repair, high-efficiency air distribution systems, and audits by certified energy raters go beyond requirements in most other states.
John Proctor, principal of Proctor Engineering Group Ltd. (San Rafael, Calif.), has been involved in reviewing the Title 24 draft document, "2005 Building Energy Efficiency Standards for Residential and Nonresidential Buildings."
His company works with building owners, utilities, and mechanical systems contractors to identify energy efficiency problems and offer solutions. It specializes in the design and evaluation of energy efficiency programs for electric and gas utility companies nationwide.
"In the HVAC area, I think there are a number of significant parts in Title 24," he said. "For instance, builders get energy credits for installing high-efficiency air-distribution systems - fans, motors, and ductwork."
Results Are RatedIt's one thing to mandate that certain things are done; Title 24 requires verification that the owners get the results they expect by having systems measured and rated by an independent third party. According to the California Energy Commission (CEC), HERS (Home Energy Rating System) raters must be hired by the owner to perform third-party diagnostic testing or field verification of energy-efficient systems or devices. The CEC certifies providers who train and monitor HERS raters.
The first training provider approved by the CEC was the California Home Energy Efficiency Rating System (CHEERS). "CHEERS provides certified HERS raters to the building industry," the nonprofit company said. "Because the construction is verified by a CHEERS-certified rater, many of the problems that cause callbacks are minimized."
"HERS raters actually take measurements off the system," Proctor said.
Is it similar to commissioning? Yes and no.
"The yes part is, they are confirming that the system is working properly," he explained. The no part is that there is a mandatory separation between the contractor and the HERS rater - they cannot be part of the same company.
CalCERTS is the only other HERS training provider for Title 24 Compliance and Energy StarÂ® Qualified New Residential Construction. The company is owned by Mike Bachand, who has taught Title 24 and model energy codes to builders, architects, Title 24 consultants, subcontractors, and jurisdictional building inspectors throughout California and Nevada on behalf of the Building Industry Institute (part of California Building Industry Association).
Both providers use rigorous training and testing to certify HERS raters. They teach the same duct tightness (Duct Blaster) test, air infiltration tests, and airflow tests. They both have to comply with the requirements in Title 24. Consistency is critical in order for the standards to work statewide.
Deal-A-KilowattAccording to Proctor, every home energy-use scenario de-scribed in Title 24 is allowed a given amount of energy consumption. When system repairs, replacements, or new construction is performed, trade-outs are allowed as long as the home (or light commercial structure) meets or exceeds Title 24's energy guidelines. It's like some weight-loss programs.
"What you have to do," said Proctor, "is design something that consumes no more energy than the Title 24 energy package does."
Under its performance approach, for example, a home builder might decide that if he installs a certain energy-saving system, he might be able to have more leeway on something like the number of windows on a south-facing wall.
"In retrofit situations, you've got options as opposed to performance requirements," he said.
In a situation where a contractor is installing a new air conditioner or furnace, the customer may be able to avoid duct testing and repairs by installing equipment that exceeds the standard's 13-SEER/78-percent AFUE requirements (SEER 14 and EER 12, and 92-percent AFUE furnace). Not that it's the best alternative.
"Overall, I think it's advantageous for everybody to get air conditioners hooked up to systems that work right," Proctor said. "It will be advantageous to the best contractors because it will level the playing field, we hope.
"The biggest efficiency problems in California and all across the country come from leaky ducts. One hundred percent of all ducts leak. The question is, which ones leak a lot? Ducts across the country are only about 60 percent efficient. That's a 40 percent energy loss nationally."
Because there is no way to enforce a national standard on duct leakage, he said, it's up to states to decide how, or if, they will try to regulate it.
"The Department of Energy is probably going to add duct tightness to the residential Energy Star program," he noted.
"There are other states concerned about leaky ducts. Florida and Minnesota are already doing some version of what California is doing."
Replacement WorkRepair/replacement HVAC work is covered in Title 24's section on alterations, replacements, and repairs. Equipment installed in a building addition must follow guidelines for new construction. In Title 24, "If you're doing an addition, you have the option of doing just the added space itself or the whole building," Proctor explained.
In a replacement job, "If you replace anything smaller than the compressor or motor, you don't have to be compliant with Title 24," he said. "You can replace an individual part and you don't have to be compliant with Title 24. If you replace the indoor coil, for sure it's considered a replacement."
Duct sealing and insulation are mandatory when air conditioners, heat pumps, or furnaces are replaced, but only in the hottest climate zones, he explained. "This is really all focused on trying to save electric energy as opposed to natural gas."
The tester can measure total duct leakage using a Duct Blaster, or measure leakage to the outside (showing structural leakage) using a Duct Blaster and a blower door. "If your total duct leakage is low enough, you're not going to worry if it's to the inside or outside," Proctor said.
A home's ductwork can pass inspection if the contractor reduces leakage by more than 60 percent compared to the initial leakage.
"What it comes down to is to avoid putting a new central air system onto a leaky duct system," he said. "Say leakage is 50 percent of fan flow and some of the leaks don't look to you like the leaks causing some of that are accessible. You'd have to reduce it by 60 percent or more. You have to get all accessible leaks, and that has to be verified by a third party."
In addition to the ductwork requirements, some climate zones require air conditioning systems that use a TXV, or refrigerant charge verification, in order to pass the HERS inspection.
The standard goes into great detail on a number of other things that affect building efficiency. For a better idea of Title 24's scope, visit www.energy.ca.gov.
Behind It AllAccording to the CEC, Title 24's revisions are based on time dependent valuation (TDV), which rates energy savings greater peak demand periods, such as hot summer weekday afternoons, and less during off-peak periods. "TDV gives more credit to measures such as high-EER air conditioning units that are more effective during peak periods."
According to the CEC, "The 2005 standards (for residential and nonresidential buildings) are expected to reduce the growth in electricity use by 478 gigawatt-hours per year (GWh/yr) and reduce the growth in gas use by 8.8 million therms per year (therms/yr). The savings attributable to new low-rise residences are 99 GWh/yr of electricity savings and 5.5 million therms. Additional savings result from the application of the standards on building alterations.
"In particular, requirements for fenestration replacement and duct sealing in existing buildings are expected to save about 41 GWh/yr of electricity and 3.0 million therms/yr of gas. These savings are cumulative, resulting in six times the annual saving over the three years to the next standard cycle.
"We learned during the 2000-2001 California energy crisis, and the East Coast blackout in the summer of 2003, that our electric distribution network is fragile and system overloads caused by excessive demand from buildings can create unstable conditions," the commission stated.
"Resulting blackouts can seriously disrupt business and cost the economy billions of dollars."
Since 2001, the CEC said it has placed increasing emphasis on demand reductions. Changes made since that time reduced electricity demand nearly 150 megawatts (MW) each year. "The 2005 standards are expected to reduce electric demand by another 180 MW each year. Like energy savings, demand savings accumulate each year."
What would the ramifications be if more states adopted similar energy standards?
Publication date: 02/07/2005