- Proper System Sizing. Load calculations (from Manual J and Manual S of the Air Conditioning Contractors of America [ACCA]) should be used to determine heating requirements. These calculations are more accurate than rule-of-thumb estimating (for example, square footage ratios). In addition, ACCA Manual D should be used to properly size the duct system.
- Proper Equipment Placement. The best location for air-handling equipment and ducts is inside the conditioned space of the home (as opposed to an unconditioned garage or attic) to minimize exposure to harsh conditions (e.g., hot, humid, dusty attics in summer). Outdoor compressors should be positioned to minimize direct sun exposure while allowing plenty of room for air to flow around the units.
- Correct Airflow. The airflow and duct leakage should be tested and airflow adjusted as necessary to improve operating efficiency, comfort, and indoor air quality.
Source: ENERGY STAR