"Say goodbye to guesswork. Manual J provides accuracy you can trust!"

Manual J-S-D is a set of residential HVAC system calculation and design guidelines developed by the Air Conditioning Contractors of America (ACCA). It is used by HVAC contractors to accurately size and select HVAC equipment for installation in residential buildings. The manual consists of three procedures, each focusing on designing and installing a heating and air conditioning system.

ACCA Manual J, heat gain/loss calculation, is the first step in designing any heating and cooling equipment for a building.

Manual J is a procedure used to calculate a home's heat and cooling load, considering all factors that affect heating and cooling, such as insulation levels, window types, and sizes, air infiltration rates, and more.

The data collected will accurately assess the home's heating and cooling requirements. And then determines the heating or cooling needed to properly condition air within an acceptable temperature range in all building parts.

Manual S considers your home's climate zone, specifications, and equipment selection, to ensure the proper heating and cooling system for your home.

It compares data from the equipment manufacturer's expanded performance tables, instead of the AHRI certificate, to determine how much capacity the equipment should have to size HVAC equipment according to the Manual J calculation.

Manual D considers the system's capacities, which ensures the ducts are of the right size and configuration to deliver the required airflow from the selected HVAC unit. It is important to understand that your home's heating and cooling systems will be ineffective without proper duct sizing.

All three Manuals are critical to ensure proper sizing and selection of equipment when installing a new residential HVAC system or replacing existing equipment. Without accurate load calculations, it would be impossible to determine the correct amount of cooling or heating required for any specific area, which could lead to inefficient operation, higher utility bills, reduced comfort levels in homes, and even damage caused by improper sizing or installation of HVAC equipment.

Yes, it is required. Section R403.7 of the 2020 ECCCNYS addresses equipment sizing and efficiency ratings. According to the Section, heating and cooling equipment shall be sized based on building loads and calculated per ACCA Manual J Manual S Manual D, and it is a mandatory requirement.