Energy Code for lighting

[mshields]

Mass now goes by ASHRAE 90.1 for it's energy code. The latest rendition of this code requires no more than 1.2 watts per square feet for a hospital.

I've just completed a Geriatric Psych Ward. Although I had generated an energy compliant lighting design, the architect completely re-did it and blew the code out of the water.

He justified this with IES recommendations for various area's in an elderly home or hospital which understandably call for higher than average foot candles. So I'm some what sympathetic to what he is trying to accomlish.

My question is this; Does ASHRAE 90.1 or the IBS (which Mass goes by) or some applicable code give you an "out" where an engineering judgement is made for more light being warranted than would otherwise be achievable at the energy code standard levels?

Thanks,

Mike

 

[ptrip]

The conflict between the energy codes, building and local codes and IES and/or owner guidelines is always a "fun" trip.

My largest issue lately is the LEED exterior light pollution point vs Ohio Schools parking lot guidelines (which tends to be brighter than IES) <sigh>.

Interior is always a struggle when it comes to 90.1 ... especially when Architects start specifying incandescent chandeliers in sitting areas and dining areas!

Are you running your 90.1 calcuations by building or by area types? I have found that, even though it's much more tedious, running it by area type gives me more allowance than by building. If your specific building has a higher percentage of medical service areas in relation to, say, storage areas or corridors compared to their 1.2 W/sq ft standard the "by building" will hurt you big time.

Also make sure you're running the correct standard. Comcheck has many codes listed (not just code, but years as well) and there are significant differences between all of them. I've struggled for hours on more than one project only to find out that I was running the most current 90.1 standard when the jurisdiction had adopted the older standard (which I was fine on).

As always, eliminate the incandescents wherever possible. Reduce any 4 or 3 lamps troffers in corridors or storage areas to 2 lamps ... this generally won't adversely affect the final light levels. If you're worried about light levels in a space, run Visual (or your lighting program of choice) ... you probably have plenty of light.

Oh ... and specific medical lighting (such as an exam light), if you have any, doesn't count against you.

Run your numbers to the best of your ability ... then run a report and show the architect that you need to still reduce the total wattage in the building by "x" to meet energy codes. Provide him/her options that will achieve the requirement (but make sure you keep some of "their" fancy stuff if possible).

Good luck ... and I'll be happy to look over stuff to help you out if you wish ... just PM me!

Pam