Both associations will work together to provide a single standard for the industry.

ARLINGTON, Va. - After the ACCA objected to a proposed ASHRAE standard on load calculations, both associations have announced that they will work together to devise a new one.

The Air Conditioning Contractors of America will cooperate with the American Society of Heating, Refrigerating and Air-Conditioning Engineers to develop proposed Standard 183P, "Methods and Procedures for Performing Peak Heating and Cooling Load Calculations."

As part of the agreement, the ASHRAE 183P committee will be expanded to include three ACCA-nominated members. The proposed standard will also reference the cooling-load temperature difference calculation method used in ACCA's Manual N.

The ACCA announced it would withdraw its intent to submit a revision of its Manual N "Load Calculations for Non-Residential Buildings, Three Stories and Less" to the American National Standards Institute.

"A single standard for nonresidential load calculation procedures will improve the accurate determination of system and equipment sizes for all types of buildings," said ASHRAE President Ronald P. Vallort. "Having ACCA's cooperation in development of the ASHRAE standard reflects the importance of having HVAC contracting and engineering communities work together in areas of mutual interest."

According to ACCA and ASHRAE, the proposed standard will not dictate a particular load-calculation method or program, but will establish a minimum level of care that would apply to any method. The standard also seeks to establish the criteria of an appropriate calculation process that will result in an accurate estimate of the air-conditioning and heating load in a building.

"ACCA's goal is to ensure that contractors have access to the most accurate, efficient and effective design standards," said Greg Leisgang, ACCA 2005-2006 chairman. "It is ACCA's intent to assure that the proposed standard meets the needs of contractors who would use this standard for light-commercial building-load calculations."