How to check the HVAC Availability Schedule of a zone program

It seems that HVAC Availability Schedule is not shown on the Honeybee_Get EP Schedules component. However, it is one of the inputs for the Honeybee_Set EP Zone Schedules component.

I want to know the on/off schedule of the Ideal Loads Air System specified for those default zone programs.

Can anybody kindly advise?

Thank you!

Hi Grasshope,

I’m not sure if there is a different HVAC Availability schedule based on program types. As you can see the availability schedule is set to Always On which means whenever that zone needs cooling or heating the HVAC will be available. In this case system will be used based on set-points and not the schedule. You can plot cooling loads and heating loads and any hour that the loads are not 0 it means the system has been on.

Mostapha

Grasshope,

Mostapha said it all and I just want to confirm that all of the zone programs use a HVAC availability schedule of ALWAYS ON whenever you set the conditioning of the zones to true. I added in the availability schedule on the Set EP Zone Schedules component just to give you an extra level of control over the system if you want it.

-Chris

Hi Chris and Mostapha,

Can I make a customized schedule for the HVAC system based on both the “occupancy Schedules” and the “set points”? It means the HVAC system will turn on only when two conditions are fulfilled simultaneously: 1)there is people in space; 2) the indoor temperature is lower the heating set point (or higher the cooling set point).

Is that correct if I did it according to the attached image (to achieve what I describe above) ?

Thank you very much in advance!

Best,

Ding

PS: What I concerned is whether the setpoints will be ignored if I make a customized schedule for the HVAC system.

Yes. If the HVAC is not available at any time-step then setpoints will be ignored. You can connect occupancy schedule directly to HVACAvailability but make sure that values are normalized to 0-1 as occupancy have cases with partial occupancy.

Mostapha

Ding,

For simulations with the “Run Simulation component”, the HVAC will only turn on when the space is outside the setpoints so there is not need to include this in the schedule. Just plug in the occupancy schedule as Mostapha says.

-Chris

I had a recent error with the set EP zone schedules component- the HVAC availabiltiy schedule input got randomly replaced with a “Ventilation Schedule” input upon updating via the Update HBee component to a more recent version (despite the fact that the machine install was directly from GitHub, about a month ago).

Not sure what’s loading from where, but would be worth checking? Which one is the more recent?

m

Max D,

The change in the schedule component was intentional. HVACAvailablity is now going to be set with the new AirDetails component for OpenStudio Systems. In other words, HVAC Availability will be set at the HVAC level instead of the zone level.

I will post more information on the workflow at the next stable release in a few weeks but I attached an example file showing the workflow to hold you over for the time being.

-Chris

Adding New Systems5.gh (541 KB)