Manual J®, the industry-standard residential load calculation procedure for indoor environmental systems published by the Air Conditioning Contractors of America (ACCA), has been enhanced for 2003. In 2002, ACCA released the eighth edition of the manual. Fully updated and rewritten, Manual J-8 greatly enhances the abilities of contractors to determine the appropriate sizing of HVAC systems for residential dwellings. It includes greater sensitivities to new construction materials and improved calculations for a wider variety of architectural features. Now, ACCA has revised the manual to make it even easier for contractors to learn and use. Color-coded sections make reference simpler, and each copy of the manual now includes an electronic spreadsheet that can be used in calculating a load according to the principles of Manual J-8. Individuals who purchased copies of the manual prior to the inclusion of the spreadsheet may download it for free at Use of the spreadsheet requires a copy of the printed manual for table look-up. Manual J®, Eighth Edition, may be purchased online at or by calling 1-888-290-2220. The cost is $79 for ACCA members, $125 for non-members. ACCA is the national non-profit trade association that represents the educational, policy, and technical interests of the men and women who design, install, and maintain indoor environmental systems.