I received an email from a Revit MEP user asking about results that don't seem to make sense. I'm writing about this because after some experimentation it seems odd to me too. This doesn't involve a complex model, just a simple test they did using a single room. I attempted to mimic their emailed explanation fully realizing that there are myriad possible things I could do differently. Despite the possible variables I was able to reproduce what they were concerned about.
Still Curious?
When they set up a test and then changed one variable (Outdoor Air) the resulting report shifts peak cooling month by one month (their result).
These are the test conditions: Walls surrounding a Space such that it is 100 SF. I placed a floor, ceiling and roof but I don't know that they did that. I used these settings for Occupancy, lighting and power.
These are the energy settings I used for the first report.
These are the energy settings I altered for the second report, only changed the Outdoor Air setting, nothing else.
These are the two reports side by side. Report on the left is the one without Outdoor Air changes and the one on the right is after changing Outdoor Air. Notice the two month advance? There are also subtle Dry and Wet Bulb values.
Their question to me and mine now as well is, "Is it reasonable to expect a so called simple change like this would cause such a jump in the calculation time frame?" I've recommended they reach out to the Autodesk Revit support team so they can examine their dataset first hand. Seems odd to me though.
I should also mention that I changed the Outdoor Air for both the Zone that the space belongs to and the Energy Settings dialog. I didn't seem to matter when I tried changing only one of those for the Outdoor Air.
Comments?? Did I miss something obvious?
Still Curious?
When they set up a test and then changed one variable (Outdoor Air) the resulting report shifts peak cooling month by one month (their result).
These are the test conditions: Walls surrounding a Space such that it is 100 SF. I placed a floor, ceiling and roof but I don't know that they did that. I used these settings for Occupancy, lighting and power.
These are the energy settings I used for the first report.
These are the energy settings I altered for the second report, only changed the Outdoor Air setting, nothing else.
These are the two reports side by side. Report on the left is the one without Outdoor Air changes and the one on the right is after changing Outdoor Air. Notice the two month advance? There are also subtle Dry and Wet Bulb values.
Their question to me and mine now as well is, "Is it reasonable to expect a so called simple change like this would cause such a jump in the calculation time frame?" I've recommended they reach out to the Autodesk Revit support team so they can examine their dataset first hand. Seems odd to me though.
I should also mention that I changed the Outdoor Air for both the Zone that the space belongs to and the Energy Settings dialog. I didn't seem to matter when I tried changing only one of those for the Outdoor Air.
Comments?? Did I miss something obvious?
No comments:
Post a Comment