We are trying to specify ceilings with at least 85% surface reflectance. However, there are areas with metal ceilings that have perforations for acoustical and fire requirements. Can these open areas of the ceiling be ignored for the credit? In some cases the open areas are 30+% of the ceiling area, and behind it is a void area where the light would get lost. From a technical standpoint, these holes do not reflect the light back down. However, the physical drop ceiling surface (metal panels) are painted white.
Does this comply with the credit?
Joyce Kelly
Architect - Cx Provider - Green Building SpecialistGLHN Architects & Engineers
27 thumbs up
January 8, 2018 - 1:03 pm
I have a similar question. On average, 70% of ceiling is acoustic tile and 30% around the perimeter and over corridors is open to MEP & FP equipment (and painted black). Can we ignore these functional open areas, which are not over workspaces or should I request ductwork, equipment & exposed structure to be painted white?
Kera Lagios
High Performance SpecialistEHDD
16 thumbs up
February 4, 2018 - 11:49 pm
Hello,
If those ceilings are above regularly occupied spaces, the lower reflectance areas must be factored into the calculation. You may exclude any portions of the ceiling area that is not over a regularly occupied space, such as the ceiling corresponding to the corridors. In addition, under the "Step-by-Step" instructions in the LEED Reference Guide, for Strategy E, you may eliminate 10% of the floor area (ceiling area) in regularly occupied spaces.
Kera
Kera Lagios
High Performance SpecialistEHDD
16 thumbs up
February 4, 2018 - 11:55 pm
In response to the question about the 85% perforated ceiling, I do not know what LEED would say officially, so it may be worth checking with them. That said, you are correct that, technically, the holes make up a large quantity of ceiling area which does not reflect light, and by a strict interpretation, should be eliminated from the overall reflectance area of the ceiling. If you compare the perf ceiling to, for example, an 85% reflective ACT, the ACT will reflect more light and will perform better than the perforated.