Let me preface my question with some context. I have a client (world famous for their electronic gadgets) who is building a lab for research and development of new gadgets and components. Access to these labs are highly controlled: each lab gives access only to specific individuals and no one lab knows what the other is working on.
The labs are so secretive that, in spite of being located in an area with floor to ceiling glass, are boarded up completely for said secrecy and security reasons. Some of the equipment is these labs consumes huge amounts of power and lighting levels are set high because of some of the work being done there: some experiments simulate the sun and there are some components being manufactured on site.
The question is, can these labs be exempt from the lighting power density calculations?
Dane Sanders
PrincipalClanton Associates
68 thumbs up
December 1, 2014 - 1:33 pm
Amit,
Thanks for your question. Laboratories and manufacturing spaces are not exempt from lighting power density calculations. How you select your space type to determine your allowable lighting power density is the key to success. If you can support identifying these spaces as a "Laboratory" or "Detailed Manufacturing", these spaces have a higher allowable power density. ASHRAE 90.1 2007 "Laboartory" = 1.4 W/SF; "Detailed Manufacturing" = 2.1 W/SF. In ASHRAE 90.1 2013 "Laboratory" = 1.81 W/SF; "Detailed Manufacturing" = 1.29 W/SF.
Some laboratories may be excluded from the Daylighting Credit calculations if you also submit a narrative describing why they should be excluded. Although, there are certainly alternatives to clear glass that would still provide both daylight and privacy. If you explore other alternatives, such as diffuse glazing, you should also carefully study the glare from these options. As a rule of thumb, a diffuse glazing should have no higher than 30% transmittance, or else the glare is likely to be uncomfortable.
Amit Ahiel
12 thumbs up
December 2, 2014 - 4:28 am
Hi Dane,
Thanks for your reply.
Some of the labs are exempt from the Daylighting credits since they are mostly server type rooms with large equipment conducting rigorous stress testing on chips and other small electrical components, so they will not be "regularly occupied".
Regarding LPD, we have already designed the labs with a Lutron (or equal) lighting control system that allows for staged increases of lighting levels according to the types of work being conducted there. My other question is: 1. Do we have to list all power levels per graduated step or start with the initial levels which are calibrated for everyday use?
2. If we do have to list each level, how is this information entered into the ASHRAE Lighting Compliance form: an average, weighted average?
Thanks again for your help.
Glenn Heinmiller
PrincipalLam Partners
96 thumbs up
December 2, 2014 - 9:10 am
LPD is based on total connected load all non-exempt loads on at full power per ASHRAE/IES 90.1, 9.1.3. Exceptions are listed in 9.2.2.3.
Bill Swanson
Sr. Electrical EngineerIntegrated Design Solutions
LEEDuser Expert
731 thumbs up
December 8, 2014 - 11:01 am
I have the 90.1-2010 User's Manual handy right now and it is using a medical laboratory that is studying the effect of lighting on a chemical process as an example. The Manual says the general lighting in the room must comply with the requirements of 90.1 but that any lighting specific to the test lighting is exempt per the exceptions listed in 9.2.2.3. As long as it is controlled separately. The reason given was that the lighting was not intended for human sight. I don't see which specific exception this is referring too but I just wanted to let you know what was in the User's Manual that might help.
Amit Ahiel
12 thumbs up
December 8, 2014 - 3:41 pm
Thanks Bill. This does help me understand the spirit of the requirements as these circumstances are specific to this type of task, which is similar to the medical laboratory work you cited.