Lighting schedule without Occupancy Sensor

asked 2024-11-20 04:07:27 -0600

Keigo
4051 ●1 ●47 ●21 https://www.linkedin.c...

updated 2024-11-20 10:32:32 -0600

Aaron Boranian

14155 ●83 ●24 http://bigladdersoftware.com/

A very basic question not specific to simulation software. I'm curious what kind of lighting schedule others are using.

For ASHRAE 90.1 Appendix G, Schedules capable of modeling hourly variations in occupancy, lighting power, miscellaneous equipment power, thermostat setpoints, and HVAC system operation shall be typical of the proposed building type as determined by the designer and approved by the rating authority, and they are basically identical in the Proposed case and the Baseline case.

If the schedules are unknown, we can use the default schedules in 90.1 User's Manual. The default schedules are based on Standard 90.1-1989, and the lighting profiles are modified to reflect the requirement for occupancy sensors in Section 9.4.1 of Standard 90.1. Below is the default schedules for office.

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Ok, we can use the default lighting schedule for zones with occupancy sensors, but what about lighting without occupancy sensors? For the lighting in corridors or lift lobbies with simple on/off control, should we set another lighting schedule like the blue line in the following chart? The blue line is 0 when the occupancy is 0, and 1 when the occupancy > 0. Or can we also use the default lighting schedule even if the lighting does not have occupancy sensors because the default lighting schedule is regarded the average one in the building throughout the year?

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For unoccupied rooms such as mechanical/electrical rooms, the lighting is seldom used. It turns on only when the rooms are occupied for the equipment maintenance. The average daily lighting time will be less than one hour. So, I usually use the custom schedule which turns on the lighting for 30 min or 1 hour per day.

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answered 2024-11-21 08:44:36 -0600

Annie Marston
4357 ●6 ●32 http://www.resustain.com

I think a lot of this will depend on what you are using the lighting schedule for and what you want to get out of your simulation.

For instance I model a lot of existing buildings and calibrate the models. I have specific schedules for say electrical rooms or places that aren't really occupied but I tend to stick with the ASHRAE schedules for occupied spaces. I run my models for a year or over 2 to 3 months to work on the calibrations. I am looking at the HVAC and the controls however and the lighting in my models is purely to help me understand the heating and cooling required by the HVAC but not much else so the generic schedules work for me.

However if I was looking specifically at lighting and lighting controls. I would be less interested in the HVAC and controls and make that more generic and look at specific lighting schedules for each individual zone type or space in order to understand the lighting in more detail. I would also model any sensors that I could in my software.

In short I think it depends a lot on the question you are trying to answer :)

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@Annie Marston Sorry for the lack of explanation. I was assuming the case of new buildings before completion in green building certifications such as LEED, BREEAM, NABERS. For the purpose of calibration of existing buildings, of course the actual lighting schedules should be used.