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

Rating System Version

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

Inquiry

Chilled Beams & Re-circulated Air The project is a 6-story new consolidated forensic laboratory facility of approximately 351,000 square feet with approximately 140,000 square feet of laboratory space and the remainder typical office space. The office space and much of the lab spaces in the building will be tempered by active chilled beams. The remainder of the lab spaces with heavy equipment loads or special requirements will be served with fan coil units that will all be equipped with MERV 13 filters. Active chilled beams are located in or directly above the conditioned spaces. They utilize ventilation air that flows through the beam. The ventilation air passes through small air nozzles which induces room air through the cooling coil in the beam and provides overhead ventilation and sensible only cooling. This technology reduces energy and the architectural impact of ductwork and mechanical systems. Finally this cooler air will fall to the floor. Once the air heats up, it will rise back to the beam to be cooled again through the natural process of convection. The ventilation air supplied to the space through the beams will be single-pass, 100% outside air and will pass through MERV 14 filters at the air handling units before passing through the chilled beams. However, the project team is concerned that the natural process of convection utilized by this system may conflict with earlier Credit Interpretation Rulings (02/12/08, 08/13/2007, 08/08/2007) that state re-circulated air inside a single space must pass through MERV 13 filters. The nature of the system prevents filtration within the beams. The project team would like clarification if air re-circulated by chilled beams is held to the same filtration standards as a forced air system if the ventilation air provided to the chilled beams is single-pass and has already passed through MERV 14 filters?