Purpose: To correct chapter 51-11 WAC, the 1997 Washington State Energy Code (WSEC), Section 503.7 Cooling with Outdoor Air (Economizer Cycle). The 1997 WSEC residential economizer requirements have an unintended consequence that would eliminate commonly used mechanical systems. This would not always result in an energy savings benefit and would ultimately result in undue expense. The amendment herein takes into consideration the general welfare of the public by reverting back to the existing residential economizer requirement.

Citation of Existing Rules Affected by this Order: Amending WAC 51-11-0503.7.

Statutory Authority for Adoption: RCW 19.27A.020, 19.27A.045, and 19.27.020.

Under RCW 34.05.350 the agency for good cause finds that immediate adoption, amendment, or repeal of a rule is necessary for the preservation of the public health, safety, or general welfare, and that observing the time requirements of notice and opportunity to comment upon adoption of a permanent rule would be contrary to the public interest.

Reasons for this Finding: The State Building Code Council (council), based on the following good cause, finds that an emergency affecting the general welfare of the state of Washington exists. The council further finds that immediate amendment of a certain council rule is necessary for the public welfare and that observing the time requirements of notice and opportunity to comment would be contrary to the public interest.

The declaration of emergency affecting the general welfare of the state of Washington is based on the following findings: The Washington State Energy Code Section 503.7 amendments contained herein as adopted by the council under emergency rule making pursuant to RCW 34.05.350, will provide economic relief to the hospitality industry (hotel and motel owners and operators), and any multifamily residential builder or building owners by allowing more realistic performance based economizer requirements. Immediate adoption of this amendment is necessary so as to not delay the construction of multifamily residential buildings, and so as not to adversely affect the state's building industry, building owners, and building tenants by imposing an unintended economic penalty.

In the spirit of regulatory reform and for consistency the State Building Code Council amended the residential economizer section in their regular 1994-1996 code change cycle. The council simplified the code language by deleting the existing requirement and replacing it with a reference to the nonresidential economizer requirements. This change had unintended consequences for multifamily residential applications. Under rules contained in the 1997 WSEC, Section 503.7 Cooling with Outdoor Air (Economizer Cycle), the residential economizer requirements would eliminate commonly used mechanical systems, would not always result in an energy savings benefit, and would ultimately result in undue expense. The council finds this to be an economic burden on the building and design industries, which will result in an increase in the cost of housing for multifamily residential buildings including hotels, motels, group homes, apartments and condominiums.

The amendment herein takes into consideration the general welfare of the public by reverting back to the existing residential economizer requirement. In order to provide immediate relief, the council finds it necessary to adopt the amendment as an emergency rule. The council also has taken the necessary steps to adopt a permanent rule. The permanent rule will not be effective until the end of the 1999 legislative session as per RCW 19.27.074.

Number of Sections Adopted in Order to Comply with Federal Statute: New 0, amended 0, repealed 0; Federal Rules or Standards: New 0, amended 0, repealed 0; or Recently Enacted State Statutes: New 0, amended 0, repealed 0.

Number of Sections Adopted at Request of a Nongovernmental Entity: New 0, amended 0, repealed 0.

Number of Sections Adopted on the Agency's Own Initiative: New 0, amended 1, repealed 0.

Number of Sections Adopted in Order to Clarify, Streamline, or Reform Agency Procedures: New 0, amended 1, repealed 0.

Number of Sections Adopted Using Negotiated Rule Making: New 0, amended 0, repealed 0; Pilot Rule Making: New 0, amended 0, repealed 0; or Other Alternative Rule Making: New 0, amended 1, repealed 0.

Effective Date of Rule: Immediately.

July 10, 1998

Mike McEnaney

Council Chair

WAC 51-11-0503 Building mechanical systems.]

503.7 Cooling with Outdoor Air (Economizer Cycle): Systems and equipment that provide mechanical cooling shall comply with Section 1413 and, as appropriate, Section 1423 or Section 1433. Each fan system shall be designed to use up to and including 100% of the fan system capacity for cooling with outdoor air automatically whenever its use will result in lower usage of new energy. Activation of economizer cycle shall be controlled by sensing outdoor air enthalpy or outdoor air dry-bulb temperature alone or alternate means approved by the building official.

Exceptions: Cooling with outdoor air is not required under any one or more of the following conditions:

1. The fan system capacity is less than 3,500 cfm or total cooling capacity is less than 90,000 Btu/h.

2. The quality of the outdoor air is so poor as to require extensive treatment of the air and approval by the building official.

3. The need for humidification or dehumidification requires the use of more energy than is conserved by the outdoor air cooling on an annual basis.

4. The use of outdoor air cooling may affect the operation of other systems so as to increase the overall energy consumption of the building.

5. When energy recovered from an internal/external zone heat recovery system exceeds the energy conserved by outdoor air cooling on an annual basis.

6. When all space cooling is accomplished by a circulating liquid which transfers space heat directly or indirectly to a heat rejection device such as a cooling tower without use of a refrigeration system.

7. When the use of 100% outside air will cause coil frosting, controls may be added to reduce the quantity of outside air. However, the intent of this exception is to use 100% air in lieu of mechanical cooling when less energy usage will result and this exception applies only to direct expansion systems when the compressor is running.

Reviser's note: RCW 34.05.395 requires the use of underlining and deletion marks to indicate amendments to existing rules. The rule published above varies from its predecessor in certain respects not indicated by the use of these markings.

Reviser's note: The typographical error in the above section occurred in the copy filed by the agency and appears in the Register pursuant to the requirements of RCW 34.08.040.