Daylighting Error

[joesinger12]

I am getting errors during the simulation saying I have 14 spaces where daylighting is required.

Yes, these are all large spaces with high ceilings and plenty of windows and skylights, but T24 Section 130.1(d)2Dii (requiring automatic daylighting controls) has an exception.

The LPDs in those spaces are around 0.2 W/sf, all less than 0.3. These errors should not be occurring, correct? Or am I misinterpreting the code?

Reported by: joesinger12

Original Ticket: cbecc-com/tickets/1507

[joesinger12]

Note that the referenced Exception 1 to Section 130.1(d)2Dii exempts spaces with < 0.3 W/ft2 from multilevel lighting requriements. However, 130.1(d)2 still requires:

"Luminaires providing general lighting that are in or are partially in the Skylit Daylit Zones or the Primary Sidelit Daylit Zones shall be controlled independently by fully functional automatic daylighting controls that meet the applicable requirements of Section 110.9."

and 130.1(d)2Div requires:

"In areas served by lighting that is daylight controlled, when the illuminance received from the daylight is greater than 150 percent of the design illuminance received from the general lighting system at full power, the general lighting power in that daylight zone shall be reduced by a minimum of 65 percent."

However, note that Exception 1 to 130.1(d)2, does exempt spaces from all daylighting control requirements if the combined total installed general lighting power in the Skylit and Primary Sidelit daylit zones is less than 120 Watts.

Original comment by: joesinger12

[joesinger12]

Lukas is correct. The LPD exception only applies to 130.1(d)2Dii, which addresses the number of control steps. So lighting with LPD less than 0.3 W/sf is not required to meet the control steps in Table 130.1-A. The total wattage in the daylit zone determines whether or not daylighting is required.

Original comment by: joesinger12

[joesinger12]

11/13 Requested user for file

Original comment by: joesinger12

[joesinger12]

11/13 User - It seems the issue goes away when you switch the Compliance type to “ExistingAdditionAndAlteration.” This project is a bit complicated, half the building is existing office being renovated to new office space, and the other half the building is previously unconditioned warehouse turning into new conditioned office space, so Existing Addition and Alteration makes the most sense to me.

I think the issue is a moot point, though for this project. This is a core & shell project, so the LPDs in the unfinished office spaces are ~0.05 W/sf – only what is required for egress. We have decided that it is a violation of the intent of the code to include lighting since the true lighting systems for the finished spaces are yet to be designed, as it would be unfair to compare our 0.05 W/sf of egress lighting to the Standard Design model’s 0.75 W/sf for lighting in open office areas. Therefore we are going to comply with the lighting requirements prescriptively for this core and shell project, with the performance model including only envelope and mechanical.

Original comment by: joesinger12

[joesinger12]

11/13 LH - I agree that it probably fits best under "ExistingAdditionAndAlteration": it seems that the altered office space would be an alteration, and the change of use areas would be new. But, the complication here is that they also have 'partial lighting', which we cannot perform simultaneously with "ExistingAdditionAndAlteration"

11/13 JA - LH is correct. The LPD exception only applies to 130.1(d)2Dii, which addresses the number of control steps. So lighting with LPD less than 0.3 W/sf is not required to meet the control steps in Table 130.1-A. The total wattage in the daylit zone determines whether or not daylighting is required

11/13 LH - It's not listed in the issue, but the user goes on to describe a additions/alterations/partial compliance scenario - need some guidnace on this

11/13 JA - I would think that the core and shell portion, if it’s the conversion of the warehouse space to office space, is a partial compliance project, so if no lighting (other than the mentioned egress) is being added at this time, the daylighting requirements should just be set so that both the proposed and standard design models have the same LPDs and same daylighting/lighting controls, if any.

Is the issue simply that they have to manually add the daylighting controls in the core and shell space, even if not showing a lighting compliance in the core and shell addition/conversion?

The user should make sure that they have the space lighting component status under the Space Status defined as “Existing” or “Future” (option available in 2016 alpha release). If they set the space status to Altered, it might enforce the lighting requirements even though the user has not yet specified lighting for the core and shell.

11/13 LH - I agree, the core and shell portion is should be partial compliance (maybe NewEnvelope, or NewEnvelopeAndPartialLighting). This would allow the user to set the lighting status to "Future" in some or all areas, and would simply install baseline lighting and daylighting controls in the user model.

The problem I see is that the altered portion of the building is an ExistingAlteration. I don't think we can currently do partial compliance and alterations simultaneously.

Maybe the user could submit the Altered and New C&S portions of the building as two separate models?

11/13 JA - That’s what I thought could be a good approach too, if we’re unable to model them together. I believe in this case the HVAC for the core and shell space may be separate from the existing, altered office space.

Original comment by: joesinger12

[joesinger12]

• Type: Defect --> Review
• Milestone: None --> Com2016B

Original comment by: joesinger12

[joesinger12]

• Milestone: Com2016B --> Com2016C

Original comment by: joesinger12

[joesinger12]

• private: No --> Yes

Original comment by: joesinger12

[joesinger12]

• Version: CBECC-Com 2013-3c --> CBECC-Com 2016.3.0
• Milestone: Com2019.1.0 --> ComDevIssue

Original comment by: joesinger12

[joesinger12]

• Milestone: ComDevIssue --> CBECC2022DevIssues

Original comment by: joesinger12