Rating System

LEED BD+C: New Construction, LEED O+M: Existing Buildings, LEED ID+C: Commercial Interiors, LEED BD+C: Core and Shell, LEED BD+C: Schools, LEED BD+C: Retail, LEED ID+C: Retail, LEED BD+C: Healthcare

Rating System Version

v3 - LEED 2009, v3 - LEED 2008, v2 - Schools 2007, v2 - LEED 2.2, v2 - LEED 2.0

Inquiry

The project team is providing individual floor air valves each with variable duration (open / close) primary air dampers and multi-position diffusers for occupant comfort conditioning as part of an under floor air distribution system. Individual floor air valves will be provided for a minimum of 50% of the building occupants. The variable duration (open/close) primary air dampers in the floor air valves will be controlled using thermostats. Multiple air valves will be connected to one thermostat, such that there will not be one thermostat for 50% of the occupants. However, all of the local floor air valves include multi-position adjustable floor diffusers which are integral to each floor air valve. At a minimum, 50% of the occupants will have control over the primary air flow direction out of the local floor air valve in their space (comfort zone) by adjusting the multi-position local floor diffuser air outlet. Changing the direction of the air flow inherently changes the speed of the airflow in a given direction. LEED NC v.2.2, First Edition, Reference Guide, p361, indicates: Conditions for Thermal Comfort per ASHRAE Standard 55-2004 include the following as primary factors: air temperature, radiant temperature, air speed, and humidity. The Reference guide also states that, "Comfort System control, for the purposes of this credit, is defined as the provision of control over at least one of these primary factors in the occupant\'s local environment" and that "Individual adjustments may involve individual thermostat controls, local diffusers at floor, desk or overhead levels, or control of individual radiant panels, and energy system design." This CIR is to confirm that providing air valves, with multi position diffusers, that allow more than 50% of the occupants to change the direction of airflow out of their floor diffuser (which changes the speed in that direction) will satisfy the LEED credit requirement for thermal comfort.