Engineers using revit?

[Waramanga]

Hi all,
Is anyone out there using revit for construction phase engineering? ie fan calcs, pump calcs etc? Seems to have a lot of promise. I am and engineer working for a contractor and our drafting is all outsourced (Revit) and then we do the calcs based on the 2d pdfs of the project. Seems like if we could model and engineer at the same time we would be better off? How does Revit fit into your engineering workflow?
I was thinking if you could get the basic design modelled and then hand it over to engineers to check details, perform the calculations, make all the final painful changes to drawings. thoughts?
thanks, looking forward to any discussion!

 

[PEDARRIN2]

Revit is a very powerful tool for design and calculations.

Our firm uses it for all aspects of design, with maybe the exception of plumbing. It has issues with calculating flows based on statistical uses and code sizing.

It is very good for determining fit issues above ceilings and in chases.

Also, remember: garbage in - garbage out. It is only as good as the information imputed.

 

[ProcessHVAC]

We use it for design, great tool but sometimes a bit more time expensive than standard CAD. Looking forward to reading answers about this topic.

 

[PEDARRIN2]

Using Revit can be more time consuming on the front end. But in my opinion, it makes up for it in the coordination effort.

In CAD, you had to look at the printed drawings/sections for A, M, E, S to coordinate. In Revit, it is mostly all in the model, so as you are inserting your pipe, you see the structural beam that is just inches too low, you see the electrical switch gear that you have to be at least 6' away from, you see the large duct that is in your way, you see just how high the architect put the ceiling so you know you have to reroute your drainage pipe.

You can put insulation on the pipe so you know how far it needs to be from an adjacent pipe.

The valves you insert can be real size so you can see if it will fit.

You can put slope on your pipe so you know exactly what invert to coordinate with the civil engineer.

You will not have the issue of trying to get a 6" pipe down in a 4" stud wall because it just wont look right. In CAD, a 2" pipe drop looks the same as a 6" pipe drop.

Yes, it is harder to input than lines in CAD, but I like it and prefer it to CAD any day.

 

[ME27272727]

The lastest versions after 2015 have come a long way on static pressure calculations. Duct taps had a hard time in previous versions accurately calculating pressure drop, but the newer versions are much more behaved. Use the pressure drop report to look for anomalies in fitting pressure drop. It's starting to become very useful. Also, system analyzer is great an looking at critical path in 3D, and making changes to duct path accordingly.

Building load calcs still have a way to go. Very limited on the system and plant level vs HAP or Trace. However, very usefull when exporting / importing gbXML files back and forth between the model and load programs.

Couple these workflows with the capabilities of Dynamo, and then you will start to see how far superior Revit is as a platform.

 

[EnergyProfessional]

Agree with all the above, very good tool for pipe/duct pressure drop (and everything else). Also use it for lighting, some electrical calcs (to some extent... every software has limits).

the problem i see with people using Revit is that they try to use it as a drafting tool, which makes it cumbersome and doesn't take advantage.

I have used Revit since 2012 i believe, now on 2017. It isn't that expensive. Back then a regular CAD version was about $5K, the package inc. CAD and Revit was "only" $1K more.

 

[ProcessHVAC]

Word on the street was that the HVAC load analysis results were somewhat questionable compared to say, HAP. Does anyone know if they have improved the algorithms?

 

[lukaiENG]

Similar to ProcessHVAC, I had heard similar bad reports on pressure drop calculations for piping and ducting. Does anyone have any idea if these algorithms have been improved?

 

[ME27272727]

The pressure algorithms have been improved in the later versions. Anything before Revit 2015 was useless for pressure calcs. You still need to keep an eye on the pressure report to check for errors. Some custom or abnormal fittings might throw you off. But I now use it regularly.

The building heating and cooling loads seem to be relatively accurate for space loads. However, when setting up systems and plants, Revit is still very lacking compared to HAP and Trace. Use the gbXML feature to send this data back and forth between Revit and the load programs still seems like the best workflow.

 

[ProcessHVAC]

Thanks for the replies. We might give it another chance for pressure/duct drops this time.

 

[irfanbaig36]

I find Revit very helpful in realtime solutions. Most of the manufacturers are providing RVT files of their products online. Well, comparing with Carrier and Trane software is not apple to apple thing. Perhaps, the recent Revit versions let you have analysis online with a membership fee.
I rate it 8/10.