HVAC Design

The following sections–titled Manual J, D, S and T–are the various components of a complete residential building HVAC design. Each of these can be selected separately or in combination.

This will provide the builder with the complete specifications necessary to properly condition the home. Armed with this information the builder can obtain quotes from various contractors and be assured that all contractors are quoting the identical requirement. Additionally, this documentation is part of the permanent record and is included in the building drawings. This can be used as a quality control instrument to gauge the performance of the contractor and as a basis for testing their work.

Manual J – Load Calculations

The Manual J, or Load Calculations, consists of drawing and site plan review, insulation, window, door and thermal boundary analysis to determine the individual room cooling and heating requirements. The amount of airflow required in each room is calculated and tabulated. This detailed room by room load calculation is the only method that can effectively eliminate the issues of hot spots and cold spots by determining the amount of conditioning required through out the day for every day of the year. This detailed analysis permits the calculation of each room’s load on a 24 hr, 395 day basis to determine if load fluctuation is excessive and zoning is required.

This analysis is conducted in accordance with ACCA Manual J version 8 and the current ASHRAE standards.

Florida Energy Code Compliance Documents: When the Load Calculation is completed the design is subjected to the Florida Energy Code requirements. Once the design meets the code then documentation stating so is produced and attached to the Manual J for submission to the local building authorities. Although this is listed separately for clarification, it is included as part of the Manual J.

Manual D – Duct Design and Specifications

This involves calculating and specifying duct sizes, distribution network, routing and connection details, and proper zoning layout. The duct routing and zoning requirements are drawn in place onto the building drawings (CAD is the preference). This analysis is conducted in accordance with ACCA Manual D and the current ASHRAE standards. Please note that structural drawings are required to properly complete the duct layout.

Manual S – Equipment Selection

This involves specifying equipment to provide the calculated cooling and heating loads. This calculation if done with the Manual J and Manual D assure maximum energy conservation, correct equipment sizing and lowest cost to the builder. This analysis is conducted in accordance with ACCA Manual S and the current ASHRAE standards.

Manual T – Grill Selection and Specification

This involves specifying grill style and type to provide low noise and sufficient airflow. The grill location is also identified on the drawing to provide floor plan grill location consistency, proper air distribution and minimize heating season window condensation. This analysis is conducted in accordance with ACCA Manual T and the current ASHRAE standards.

Comments are closed