Recommended or Commonly Accepted MEP Loads? 2

[YoungCapacityEngineer]

Good afternoon all,

I've been looking for a commonly accepted MEP and building material dead loads (kpa, psf) to use for seismic weight estimation of condominiums and office buildings. I recognize that loads can be calculated directly based on expected actual installs, however our present engagement requires a lot of repetition and subsequently a "rule of thumb" to speed things up would be greatly appreciated. With that said, we have resources in the office that are older, and provide these values, however I am not confident that they are still OK to use.

Does anyone know where or if such tabulated data may exist? I am also aware that the use of these will result in conservative values that are higher than reality. What do you folks use to estimate these loads? I have reviewed other threads and whatever I could find online but they appear to be inconclusive with differing opinions/values.

Thank you for any and all guidance that you may have.



B.Eng. (Carleton University)
Create. Enhance. Sustain.

 

[spats]

See Chapter C3 of ASCE 7-16.

 

[milkshakelake]

Besides what spats said, it's hard to estimate these loads and I don't think the MEP engineer would give it. I use 3 psf as a rule of thumb which is probably more than what will actually occur in a condo. 2 psf for drop ceiling. For a 100'x100' building, this results in MEP load + drop ceiling of 50 kips per floor which is way more than what will realistically be built.

For a roof, I use 30psf plus equipment loads. It seems like MEP engineers are going for separate air condensers for each unit these days for low to mid rise condos, which are about 100-200 lb each so large rooftop unit loads are becoming rare. The psf of a small air condenser becomes less than 30 psf. I'm not sure how large are the buildings you're designing, but large MEP equipment is more of a common thing on industrial projects and high rises.

 

[YoungCapacityEngineer]

@spats As a Canadian EIT, thank you for this. Never knew this document existed. But the price tag - yikes.

B.Eng. (Carleton University)
Create. Enhance. Sustain.

 

[YoungCapacityEngineer]

@milkshakelake Thank you for the input. Your comment regarding mechanical systems such as HRVs being installed per unit is certainly true. The project in question is a new midrise condominium but we also deal with older buildings on a regular basis. I appreciate you taking the time!

B.Eng. (Carleton University)
Create. Enhance. Sustain.

 

[phamENG]

I believe the ASCE dead load list has 4psf for MEP loading from wiring, lighting, ductwork, etc. It doesn't take RTUs or large pieces of equipment into consideration. These numbers are good for designing floor systems. It's very unlikely that a single joist designed for this will be overloaded by the added weight of MEP. But as milkshakelake mentioned, this is way over the top for seismic calculations. For a typical condo or office building, general MEP is probably closer to 1psf when calculating seismic weight, and even that is probably conservative.

As for units, milkshakelake has provided some good numbers. For office buildings, you may see some larger RTUs in the 400-600lb range if there's no room to put them out back.

 

[dik]

A BPS for your replies...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik