What are the steps to simulate the natural ventilation inside a thermal zone.

asked 2017-11-15 10:39:29 -0500

Palmiere's avatar

updated 2017-11-15 13:39:19 -0500


Can anyone tell me the steps to set a natural ventilation to a thermal zone.

I acessed the Zone Ventilation Design Flow Rat and set the natural ventilation, I just changed the mininum and maximum Indoor and Outdoor temperatures. The ventilation type is natural and the schedule name I kept the Always on Discrete 1.

When I simulate with the natural ventilation or without it, the results are the same.

Can anyone tell what are the right steps?


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What results are you looking at. Are you looking at consumption or zone temperatures, and how is the space conditioned? I would also check simple ventilation values in eplustbl.html to make sure conditions exists where ventilation is occurring.

David Goldwasser's avatar David Goldwasser  ( 2017-11-15 11:40:48 -0500 )edit

Hi. I've created a simple model just to test how to apply natural ventilation. In my model i set 2 thermal zones feed by a packaged rooftop heat pump and I have another thermal zone set as a lobby feed by natural ventilation. I want to set the natural ventilation through the lobby and check the interference in the other two thermal zones and in the building energy consumption.

Palmiere's avatar Palmiere  ( 2017-11-15 12:30:43 -0500 )edit

Do you have matched surfaces between the lobby and the two other zones? otherwise you wouldn't see any energy consumption changes related to natural ventilation.

David Goldwasser's avatar David Goldwasser  ( 2017-11-15 14:32:45 -0500 )edit

Hi David. Yes I matched the surfaces applying the tools at Openstudio/Sketchup menu bar. Is there another way to do that?

Palmiere's avatar Palmiere  ( 2017-11-16 11:21:02 -0500 )edit

There are a number of ways to match surfaces, in many cases that also requires intersection to split surfaces that are not a 1 to 1 match. You should check that it was done correctly by either using render by boundary condition in the SketchUp plugin, or look at the space>surfaces tab in the OpenStudio application to look for boundary condition of interior surfaces. Even if this isn't done you could look for changing zone temperatures in the lobby with and without the ventilation in the model.

Also are you not seeing any consumption changes at all, or are they just smaller than you expect?

David Goldwasser's avatar David Goldwasser  ( 2017-11-16 16:08:45 -0500 )edit