Source: The Building Codes Assistance Project
On January 23, 2006, DOE's regulations under the National Appliance Energy Conservation Act (NAECA) established a new efficiency standard for certain heating and cooling systems. The greatest impact of the new requirements is on residential sized central air conditioners and heat pumps, whose minimum efficiency ratings are now SEER 13 for cooling and HSPF 7.7 for heat pump heating. NAECA is primarily understood as a manufacturing standard mandating that any new equipment produced in or imported to the United States beginning on the effective date be at least as efficient as the minimums. While NAECA does not prohibit the sale or installation of “old” equipment, it does contain lesser understood requirements governing state building codes with respect to the efficiency of equipment, as described in the set of Frequently Asked Questions below.
It is important for code officials, builders, and other stakeholders to understand the new limitations and to respond to the change. The US Department of Energy has developed its interpretation of the issue in two important ways. First, they have issued guidance to the states on relevant changes for them to consider to their codes. (See http://www.energycodes.gov/residential_ac_hp.stm) Second, DOE has issued a new version of REScheck software (v 3.7, release 1b) which incorporates the new NAECA requirements. (Free download at http://www.energycodes.gov/rescheck) In addition, the Building Codes Assistance Project is available to assist states with understanding these important changes.
FAQs presented by the Building Codes Assistance Project (also available in .pdf: NAECA FAQ.pdf)
Q. What is NAECA?
A. NAECA stands for the National Appliance Energy Conservation Act. This federal law was adopted by Congress in 1992 to establish nationwide minimum efficiency levels for a variety of residential and commercial appliances that use energy and water. The US Department of Energy (DOE) has the responsibility of implementing NAECA, including updating minimum required efficiency levels periodically. As new technologies and manufacturing techniques make higher levels of energy efficiency more affordable, DOE increases the NAECA minimums to reflect these improvements that are "technically feasible and economically justified." NAECA minimums generally preempt (nullify) state and local regulations, including building/energy code provisions that are inconsistent.
Q. What NAECA-related changes have occurred?
A. The most recent improvements are for residential-sized HVAC equipment, and they took effect on January 23, 2006. (These changes were announced in 2001, giving the industry time to retool.) Most prominent among these are air conditioners and heat pumps, which now have increased efficiencies as follows: central air conditioning equipment must be rated with a minimum Seasonal Energy Efficiency Ratio (SEER) of 13 (up from the old requirement of SEER 10), and heat pumps must also be rated with a minimum Heating Seasonal Performance Factor (HSPF) of 7.7 (up from 6.8.)
Q. Can "old" equipment still be installed?
A. Yes. The NAECA efficiency requirements focus first of all on manufacturers and importers. As of January 23, 2006, it was illegal to manufacture or import equipment that fails to meets the new NAECA minimums. Under these regulations, inventories of equipment manufactured before that date may still be installed in new or existing homes.
Q. How does this affect building codes?
A. Most states and local jurisdictions have energy efficiency requirements in their building codes, and the change in NAECA does have an impact. Many energy codes allow for reductions in the efficiency of insulation or windows if high-efficiency HVAC equipment is installed. As of January 23, 2006, air conditioners and heat pumps will need to exceed the new NAECA minimums for such trade-offs to be allowed. In other words, while "old" equipment can still be installed in new construction, no credit can be taken for trade-offs unless they reflect a baseline of SEER 13 for cooling and HSPF 7.7 for heat pump heating cycle.
Q. Do these regulations supersede requirements in my state or local code?
A. Yes. NAECA includes specific authority to preempt the provisions of state and local codes that contain inefficient HVAC equipment as the basis for trade-offs. In general, the regulations do not invalidate the entire code, only minimum equipment standards, trade-offs or baselines based on lower values than the new NAECA minimums. If a state or local code allows trade-offs through software, hand calculations, or from tables, no credit can be taken for equipment unless the compliance path/trade-offs are modified to include a baseline of the new NAECA minimums, and the equipment exceeds the NAECA minimums, which as of January 23, 2006 are SEER 13 and HSPF 7.7.
Q. How is the NAECA issue addressed in building code compliance software?
A. All developers of energy code compliance software should be preparing updates that include the new NAECA minimums as the baseline for trade-offs. The US Department of Energy has already updated its REScheck software in Version 3.7 Release 1b, available for no charge at www.energycodes.gov. Since the new NAECA standards took effect on January 23, 2006, the software no longer provides credits unless equipment exceeds the new minimum. If you use software from other organizations, you should make certain that the HVAC baseline for trade-offs are SEER 13 and HSPF 7.8.
Q. Can “old” compliance software legally continue to be used after January 23, 2006?
A. No. Earlier versions of REScheck (and any other compliance software) should be replaced with a new version that complies with NAECA minimums. Software with different baselines will provide compliance documentation which violates the law.
Q. What should states and local jurisdictions do in response to the changes in the NAECA minimums?
A. It depends on their particular code. For those codes that contain specific references to HVAC minimums (including any specific trade-offs), such provisions should be revised as soon as possible to reflect these changes. Additional information and assistance is available from DOE, as well as from other organizations such as the Building Codes Assistance Project (BCAP) and the Responsible Energy Codes Alliance (RECA.) Some states have already acted. For any state that allows HVAC trade-offs or performance analyses, the state should no longer accept trade-offs based on outdated compliance software, outdated trade-off packages or baselines weaker than the new federal minimums.
Q. Why are these changes important for energy efficiency?
A. The intent of NAECA is to capture new appliance technologies that have been proven so reliable and affordable that anything less efficient is obsolete. The new air conditioner and heat pump minimums fit this description perfectly. The value of these efficiency upgrades is that they will cost-effectively save substantial amounts of energy for consumers and for the nation. If the trade-off baseline in codes had not been raised to incorporate the new NAECA minimums, then these potential savings would not be realized; although higher efficiency equipment would be installed, the trade-off would have allowed reducing the efficiency of the building envelope, thereby negating the improvements intended through NAECA. In other words, we would have more efficient equipment but still use the same amount of energy. This could amount to over 1.3 billion kilowatt hours per year, or about one Quad of energy over 20 years. As a result, NAECA was drafted to explicitly address this problem by preempting state and local codes that contained inconsistent baseline values.