LEED modelling schedules

The schedules in the User's Manual or the default schedules in the modeling software can be used but should be reviewed and adjusted based on the expected facility schedule. The modeling schedules can have a major impact on the ultimate results. We spend a great deal of time interviewing the design team and owner to, as accurately as possible, use schedules that will reflect the way the building will be operated.

There is no process necessary to get any schedule approved. You can use any schedule you like. The only Appendix G requirement is that the schedules are identical in both models.

I would like to expand on this question in terms of how do you fairly make baseline occupancy schedules match the proposed schedules when your baseline building requires a single VAV system instead of several independent proposed systems with unique operating hours. Or is that part of the intended inherent savings?

I have an 83,000 sqft church project with several different areas that are used on different days and unoccupied the rest of the week, while other areas are occupied six days a week, all day long.

About 18,000 sqft is occupied at part load five days a week with brief peaks of full load on Sundays. The majority of the remaining areas are occupied only on Sundays or Sundays and one or two evenings per week. Some of these areas are used for three hours on Tuesdays and Thursdays while others are used for three hours on Wednesdays. And then there are lots of usually unoccupied areas like storage rooms, utility rooms and mechanical rooms.

The predominant case is most of the total building area is unoccupied most of the week. And it doesn't appear any Exceptions for additional systems apply, except maybe utility rooms where we have dedicated cooling for transformer loads and other equipment. So it seems the Appendix G baseline system would be two Packaged VAV systems with gas-fired hot water reheat (one for the first floor and one for the second floor). There are some additional loft spaces (mechanical room, storage rooms and an attic storage room above one of the first floor spaces), but I assume we can just count those as part of the second floor, correct?

So assuming we go with just the two baseline systems for the everything but the special tech/utility rooms, what is the correct way to model occupancy schedules both for interior loads and ventilation/fan modes and thermostat setbacks since the proposed design with 20+ systems has quite a bit of variance from system to system in terms of when they are in "occupied" mode and "unoccupied" mode? The VAV boxes can shut back obviously, but are we to control ventilation on the rooftop units to constantly adjust to what is being called for? Does the unit have to remain in "occupied mode" as far as temperature setpoint until the last space becomes unoccupied for the day?

Thanks in advance for any help. This site has been a great resource.

I can see possibly expanding the occupancy schedules of the mostly only used on Sunday spaces to all have the same hours of use including a couple of evenings other than Sundays, but what about that 18,000 sqft common area that is open all week long and needing ventilation 13 hours per day?

G3.1.1 Exception b allows you to model a system 3 or 4 in those areas with a different enough schedule.

Yes, I realize that, but it's not clear "how much different" is "different enough".

If I have 18,000 sf of space that has lights on and anywhere from 5-1,000 people in it 13 hours a day, six days a week, is that different enough from the remaining 65,000 sf of the building which only has the lights on and varying amounts of people in it about 15 hours per week? It definitely varies by more than 40 hours per week, but the whole "equivalent full-load" part I'm not so sure. Regardless, it seems the fair way to do it is to isolate this 18,000 sf area so that the remainder of the building can be scheduled closer to reality and not have to have the outside air damper open all week long just to satisfy this one area.

That is more than the 40 hours. Basically it is the difference in occupied hours you are evaluating.