Relation of honeybee Set EP Loads and Set EP Zone Schedules

Hi all,

It's my first post to this forum so I hope that it is in the right place. Correct me if I'm wrong!

Currently I am setting up an energy model with Honeybee. All works fine, but one thing isn't clear to me; the relation between the loads and the schedules.

My question is; is the schedule a factor with which the load is multiplied, or is the load just overwritten by the values of the schedule. It's easiest to explain with an example:

Example, if I want a daytime temperature of 20 and a nightime of 15 do I need:

A: Load = 20, Schedule is (1,1,0.75,0.75, 1, etc.)

B: Load = anything, Schedule is (20,20,15,15,20 etc.)

See the file attached for (the relevant part of) my HB model.

Greetings,

Vincent Höfte

Attachments:

Graduation_GH_Ref04_Question.gh, 56 KB

Replies to This Discussion

Permalink Reply by Chris Mackey on July 31, 2017 at 7:54pm

Vincent,

Sorry again for the late response. To answer your question, it depends on the units of the schedule. Most schedules in Honeybee are fractional schedules (schedules that go from 0 to 1) and these get multiplied by the load to give you the hourly load in the simulation. The schedules that be have this way include lighting load, plug load, occupancy, ventilation, Nat Vent Opening Area schedules, and HVAC availability schedules, and a few others I may be forgetting.

There are only two schedule types in Honeybee that do not follow this pattern: temperature schedules (for thermostat set points), and occupancy activity schedules. In this case, the values of the schedule are the temperature that you want for that given hour or the metabolic rate of the average occupant for that hour. These values basically "overwrite" the existing ones as you say.

You attached file is almost correct, you just want to make sure that you specify the units for your CSV schedule when you create one that is not fractional (the default):

Also, you are overwriting your setpoint schedules on the Set Zone Thresholds component.

-Chris

Attachments:

Graduation_GH_Ref04_Question_CWM.gh, 497 KB

Permalink Reply by Vincent Höfte on August 1, 2017 at 1:26am

Thanks for your reply Chris, all is clear now. I think I was confused by the two schedules that were an exception to the fractional-schedule type of functionality.

To be honest, by a lot of trial and error I happened to get a functional model already... but it's good to understand the functionality of schedules completely now!

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