Sample MEP file

[yes_and_no]

I m looking at OTB sample MEP file R17, arch version. In setting I saw default office space is about 250sf/occupant. We knew B occupancy is 100sf/occupant. I wonder if this 250sf/occ is a reliable data from mechanical codes or just Revit being "who cares" ? Anyone ?

[barthbradley]

What's the question?  

BTW: my Revit cares a lot.  😉  

[Edwin.Rense]

For us in the Netherlands the (MEP) refreshfactor depends on both occupancy and the type of 'work' that is done in the space.

So the values might be correct, but maybe not for you.

I can image you having to change the values to your needs.

I cannot image that you can only use 1 value for all types of spaces. So 250/occ seems legit for a 'heavy' work environment (office like), while 100/occ seems more legit for hallways.
But it all depends and 'rules and regulations'

Or do you mean its the minimum required space (if sf means square feet) needed per occupant instead of the refreshrate,

The Space has the 'people' parameter which contains the 'Occupancy' and 'Heatgain per person'

Both can be set to 'By space type' which would result in the upper conclusion.
When set to Specified the default values are overruled and set to 'any' value which may or may not make sense.

If you change the setting to space type an set the required space type, it should give you the correct values. But only if you use the same rules and regulations.

[ToanDN]

100 (or 150 in the most current IBC) is the Egress Occupant Load Factor for Group B.   250 (or 200 in the most current IPC) is the Occupant Load Factor for plumbing fixture calculations for Group B.

They are for different purposes and there is no contradiction.

[RobDraw]

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@yes_and_no wrote:

We knew B occupancy is 100sf/occupant. 

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What does this mean?

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I wonder if this 250sf/occ is a reliable data from mechanical codes or just Revit being "who cares" ? Anyone ?

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Any default values in Revit are just that, default, and are meant to be changed. In HVAC, there are many occupancy rates based on use and type of building.

When you actually start using this data, you will find that it's not about caring. It's SCIENCE! Remember that the next time you are feeling like Revit doesn't care.

[RLY_15 · Accepted solution]

Are you referring to this:

To my knowledge, this is the ASHRAE 62.1  space occupant density, converted from the metric values in the occupancy tables (the information is presented as either #/1000sf or #/100sm). 

ASHRAE space occupant density is not Building Code building occupant density, egress load density, occupant density for plumbing fixture count determination, etc. the rationale between each density figure is based on that industry's needs.

Since the space definitions in Revit are established for Energy Analysis, there is some logic in defaulting to the various ASHRAE standards and fundamentals resources....that being said, your local jurisdictions can always vary.

When it comes to preset values in Revit, you're going to find that exceptionally few are 'who cares' values - generally they're based on some industry's most common or notable standard of care. They are not, however, one-size-fits-all.

[yes_and_no]

• Thank you. I don't know if I have to spend 200bucks for an ASHRAE book, but this ref definitely saves me time looking at the right chapter, perhaps in CMC.

[RobDraw]

You're welcome. 

[ToanDN]

https://up.codes/codes/california

[RLY_15]

https://www.ashrae.org/technical-resources/standards-and-guidelines/read-only-versions-of-ashrae-sta...