When building a new home, you have the opportunity to be part the HVAC system design. Understanding the basic characteristics of a quality installation will help you ask your installer the right questions. You should expect your air conditioning installer to take the following steps:

• Determine room-by-room loads and air-flows using ACCA Manual J calculation procedures (or equivalent).
• Lay out duct system of floor plan, accounting for the direction of joists, roof hips, fire walls, and other potential obstructions. Determine register locations and types, duct lengths, and connections required to produce layout given construction constraints.
• Size duct system according to ACCA Manual D calculation procedures (or equivalent).
• Size HVAC equipment to sensible load using ACCA Manual S procedures (or equivalent).
• Install equipment and ducts according to design specifications.
• Charge the system appropriately, and verify charge with the evaporator superheat method or subcooling method (or equivalent).
• Check for proper furnace burner operation and fire-box drafting.
• Test the system to ensure that it performs properly by determining that the system is properly sized, it does not leak substantially, and has either proper air handler fan flow, and proper plenum static pressures, or proper room and return air flows, and proper plenum static pressures.
• Have the installer run a Total Performance Diagnostic report to verify proper SEER and BTU output.
• Provide an AHRI Reference number or AHRI Certificate of Certified Product Performance, which verify the technician has installed a properly matched system.