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Requirements
A. Forced-air systems:Prerequisites
6.1 Room-by-room load calculations. Perform design calculations (using ACCA Manuals J and D, the ASHRAE Handbook of Fundamentals, or an equivalent computation procedure) and install ducts accordingly.Credits
6.2 Return air flow or room-by-room controls (1 point). Ensure that every room (except baths, kitchens, closets, pantries, and laundry rooms) has adequate return air flow through the use of multiple returns, transfer grilles, or jump ducts. Meet one of the following requirements:a. Size the opening to 1 square inch per cfm of supply (this area may include free area undercut below door).b. Demonstrate that the pressure differential between closed rooms and adjacent spaces with return is no greater than 2.5 Pa (0.01 inch w.c.).6.3 Third-party performance test (2 points). Have the total supply air flow rates in each room tested using a flow hood with doors closed or one of the other acceptable methods cited by the ACCA Quality Installation Specifications. Supply air flow rates must be within +/– 15% (or +/– 10 cfm) of calculated values from ACCA Manual J (as required by EA 6.1).B. Nonducted HVAC systems (e.g., radiative systems):Prerequisites
6.1 Room-by-room load calculations. Perform design calculations (using ACCA Manual J and D, the ASHRAE Handbook of Fundamentals, or an equivalent computation procedure) and install system accordingly.Credits
6.2 Room-by-room controls (1 point). Design the HVAC system with flow control valves on every radiator.6.3 Multiple zones (2 points). Install nonducted HVAC system with at least two distinct zones with independent thermostat controls. See all forum discussions about this credit »What does it cost?
Cost estimates for this credit
On each BD+C v4 credit, LEEDuser offers the wisdom of a team of architects, engineers, cost estimators, and LEED experts with hundreds of LEED projects between then. They analyzed the sustainable design strategies associated with each LEED credit, but also to assign actual costs to those strategies.
Our tab contains overall cost guidance, notes on what “soft costs” to expect, and a strategy-by-strategy breakdown of what to consider and what it might cost, in percentage premiums, actual costs, or both.
This information is also available in a full PDF download in The Cost of LEED v4 report.
Learn more about The Cost of LEED v4 »Frequently asked questions
See all forum discussions about this credit »Documentation toolkit
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