Forum discussion

NC-v4 EAp2:Minimum energy performance

Interior lighting of Dwelling units

 Greetings,

The issue is how to model Dwelling units, having in mind that they are not regulated by ASHRAE 90.1. More specifically it refers to the energy model, which is to be provided at Design review stage. The only available LPD in Table 9.6.1 of ASHRAE Standard is for Dormitory, which however is close but different to Dwelling unit.

As recommended by reviewers, I went through the Simulation guidelines of MFHRP and also through LEED Interpretation 5253.

The conclusion I’ve resumed and I’m planning to apply are:

1. Taking credits based on interior lighting savings in dwelling units must be claimed using an Exceptional calculation method

2. This kind of lighting power appears to be considered as process load.

3. The LPD for dwelling units should be entered identical in Baseline and Proposed Design, unless Exceptional Calculation Methodology is provided as described in the reference documents mentioned above.

4. The LPD is to be 1.1 W/sf as stated in the Simulation guidelines of MFHRP, Version 1.0, Revision 02, September 2013.

5. Baseline and Proposed Design lighting inside dwelling units shall be modeled as lit for 2.34 hours per day as per item 3.6.2.5 of the Simulation guideline.

6. This kind of lighting power shall be entered in the Process tab of MEP Calculator as Non-Receptacle Process Equipment

Please provide some comments and/or confirmation of the assumptions I’ve summarized above, so that to be able to comply correctly to the LEED and ASHRAE requirements.

0

You rely on LEEDuser. Can we rely on you?

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

Go premium for $15.95  »

Thu, 11/05/2020 - 19:09

Sounds right. You will also need to provide illuminance calculations demonstrating that the required light levels are achieved by the proposed interior lighting design.

Fri, 11/06/2020 - 07:21

Hi Marcus, Thanks for he reply. One small clarification though. When mentioned 2.34 hours per day, does it mean 2.34 of 14 hours or 9.75%.  

Fri, 11/06/2020 - 07:22

Sorry for the mistake - 2.24 of 24 - 9.75%

Fri, 11/06/2020 - 15:51

Yes the lighting schedule should reflect that the lights are on 2.24 hours within a 24 hour period, each day of the week.

Thu, 02/11/2021 - 09:03

In the page of Interpretation 5253 the Rating System v. 4 is not mentioned: https://www.usgbc.org/leedaddenda/5253 And as "International Applicable" the answer is no. But shall I apply that in Europe for  Rating System v. 4? Otherwise, I don't know which other method I shall apply. Best Regards

Thu, 02/11/2021 - 15:31

Here are the guidelines for modeling multi-family projects. https://www.usgbc.org/credits/multifamily-energy-model-simulation-guidelines?view=resources&return=/credits/Undefined/undefined

Fri, 02/12/2021 - 16:28

Yes the lighting design must meet the illumination requirements and you have to demonstrate that they do meet those requirements. In the past I know the document contained the light levels required. The IES values in the first table at the link you provided look too low to me.

Add new comment

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