There are two key resources for designers on whole building and retrofit design. They include:

1. Air Conditioner Contractors Association (ACCA) Manual D - Duct Systems. Design a residential duct system in less time with the streamlined duct sizing procedure in this revised edition of Manual D. This procedure can be applied to constant volume systems and zoned, variable air volume systems, over the full range of duct construction materials. Manual D also includes comprehensive equivalent length data.
   
   
2. Air Conditioner Contractors Association (ACCA) Manual J - Load Calculations. The new MJ8 procedures produce improved equipment sizing loads for single-family detached homes, small multi-unit structures, condominiums, town houses and manufactured homes. Manual J outlines these procedures.
   

These materials can be purchased through the ACCA website.

Additionally, there are two other resources for designers including:

1. The Building Energy Tools website by DOE describes 248 energy-related software tools for buildings, with an emphasis on using renewable energy and achieving energy efficiency and sustainability in buildings.
   
   
2. EEBA Builder's Guides (for Cold, Mild/Dry, Hot/Dry, and Hot/Humid Climates) provide the building industry with the latest and best practical information on how to apply building science principles to structures as systems in each of these four climate regions. EEBA's guides embody much of what is now known about building homes that are affordable, durable, energy efficient, healthy, safe, comfortable and environmentally responsible.