See all forum discussions about CI-2009 EAc1.2
 Subscribe to new posts about CI-2009 EAc1.2 Post a new question aboutCI-2009 EAc1.2
See LEEDuser’s guidance on CI-2009 EAc1.2»
FAQs about EAc1.2 :

Does decorative lighting need to be connected to daylight sensors?

What is included in the total connected lighting power?

View answers »

Forum discussion

CI-2009 EAc1.2:Optimize Energy Performance—Lighting Controls

Percentage of Light Output/Wattage Dimmed

Default Avatar
Jordan Kirrane
Associate
Hurley Palmer Flatt
LEEDuser Basic Member
5 thumbs up

Hi there, For the daylight control point I was wondering by how much the group of lights need to be reduced by, and whether this percentage needs to be of the total wattage or light output? The intent is to control 3 rows away from the facade using a multi-sensor (occupant & daylight sensor in one) at varying reductions (25%, 50%, 75% of full) and then control the internal circulation lights to a lower reduction using a separate daylight sensor. Could the circulation zones be reduced by a minimal amount (e.g. 5% of full)?

0
Post a reply

You rely on LEEDuser. Can we rely on you?

LEEDuser is supported by our premium members, not by advertisers.

Go premium for $15.95  »

Profile picture for user sheffer
Marcus Sheffer
LEED Fellow
7group / Energy Opportunities
LEEDuser Expert
4454 thumbs up

Tue, 03/22/2016 - 22:02

I do not think there is a required minimum reduction. Hard to say anything about the circulation zones without seeing the plans.
Default Avatar
Jordan Kirrane
Associate
Hurley Palmer Flatt
LEEDuser Basic Member
5 thumbs up

Wed, 03/23/2016 - 09:25

Marcus, many thanks for your response. The circulation areas are not physically separated to the open place office spaces (the regularly occupied spaces). Therefore playing it safe I would see these as being the one space, and thus requiring some sort of dimming response to daylight. However as these are are very deep in to the floor plate (10m/33ft) so I don't see the benefit of providing daylight dimming control. Even with high glazing the spaces are too deep for it to be beneficial. Would you agree?
Profile picture for user sheffer
Marcus Sheffer
LEED Fellow
7group / Energy Opportunities
LEEDuser Expert
4454 thumbs up

Wed, 03/23/2016 - 13:56

The rule of thumb for an effective daylit zone is 1.5 times window head height. So you would need about 20 foot tall windows to provide any kind of adequate daylight. If on the south side you can augment the depth of penetration to up to 2.5 times window head height with a light shelf. Again hard to say with seeing it.
Default Avatar
Jordan Kirrane
Associate
Hurley Palmer Flatt
LEEDuser Basic Member
5 thumbs up

Wed, 03/23/2016 - 15:07

Marcus, would it be possible to forward on a typical floor to get a better understanding of the implications? Also the intent of EAc1.2 are for daylight controls where relevant, not to improve the daylighting levels. Therefore if the above rule of thumb holds true the circulation areas that are over this distance from the facade do not need any daylight controls as they will never received enough daylight to warrant this kind of control?
Profile picture for user sheffer
Marcus Sheffer
LEED Fellow
7group / Energy Opportunities
LEEDuser Expert
4454 thumbs up

Wed, 03/23/2016 - 15:23

I answer questions here because it is in a public forum benefiting many. Sending me drawings crosses the line into my fee for service consulting practice. I agree that if you have an area too far to receive effective daylighting then installing daylighting controls for that area makes no sense. Unfortunately this may be a case where chasing a LEED point makes no sense either.

Add new comment

To post a comment, you need to register for a LEEDuser Basic membership (free) or login to your existing profile.