Hi all,
I had review back for my ASHRAE 90.1-2007 model for a LEED project (office building) and would need some advice on how to address the subject.
In the first submission of the project I had made a mistake where I did not account for occupancy sensors in baseline model. Therefore, the reviewer commented to account for occupancy sensors for both baseline and proposed models. But I'm getting confused about the requirements of Section 9.4.1.1 and Table G3.2.
According to section 9.4.1.2(a), occupancy sensors are required particularly in conference and meeting rooms and employee lunch rooms. In other rooms either manual or occupancy sensing control device can be used. In the proposed building, occupancy sensors are used in meeting rooms, employee lunch room, office zones, lobbies and circulations, lounge areas. In my proposed model I accounted for occupancy sensors by switching the lighting schedules to the occupancy schedules. According to reviewer, I have to correct baseline model lighting schedules to be the same as the ones used in my proposed model, which will be done.
But can I claim the additional 10% savings from table G3.2 in my proposed model (project is a 840,000 sq ft office building )? If so, should i apply the 10% savings to all the rooms with occupancy sensors excluding the room listed in 9.4.1.2(a)? Can i claim the 10% savings in all rooms of my proposed model with occupancy sensors? Or am I missing the point about how and where to use the 10% savings in lighting power adjustment?
Also, daylight harvesting is done in office area (aprox 590,000 sf). Can I claim further savings in my proposed model for that? Table G3.2 does not mention any adjustment for daylighting.
Thanks in advance.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
June 28, 2019 - 2:14 pm
The best way to do this is to model the proposed as designed and the baseline with occupancy sensors where required. In spaces where occupancy sensors are not required you can claim the 10% LPD reduction in the proposed.
The baseline does not include any daylighting controls under 90.1-2007, so model the proposed as designed and the baseline with no daylighting controls.
Christophe Boussuge
July 8, 2019 - 11:43 am
Hi Marcus thank you for your answer and sorry for my late reply.
So if I understand correctly, should i model my models this way:
- rooms where occupancy sensors are required: switch the lighting schedules to the occupancy schedules (100% occupancy from 9 to 12 and 2 to 6 with reduction during lunch time) in both proposed and baseline models
- rooms where occupancy sensors are not required: lighting schedule on continuously (100% from 9 to 6) in both proposed and baseline models and claim the 10% LPD reduction in the proposed model where occupancy sensors are actually designed in the proposed project?
Thanks in advance for your advice
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
July 8, 2019 - 3:01 pm
You should just claim the 10% LPD credit whereever occupancy sensors are installed in the proposed and required in the baseline. Do not use different schedules.
Christophe Boussuge
July 10, 2019 - 2:51 am
Ok thank you very much for the clear answer Marcus