Ceiling void, chasiss type fan coil units modeling

[andre.gawlik]

Greetings to all,

I've been trying to create family of fan coil units but run in to trouble.

First of all, discharge spigot configuration is variable depending on the unit's duty. I managed to create family types to represent different sizes and parametrically array spigots to get the required number of them - but array allows minimum of two, how to represent unit with only one spigot?

Secondly, the fresh air supply is discharged to the back of the unit but not physically connected with it - how would I need to maintain system integrity from the air handler through fan coil to supply diffuser?

Thirdly, say unit has six spigots but only two of them are used to supply air to diffusers - how to configure connectors on so one won't end up with unassigned systems in the system browser?


How would you guys / girls would go about modelling this kind of equipment and how would you configure connectors - inlet, which is physically not connected but maintain logical connection with fresh air supply and make-up air from ceiling void, and multiple outlets configuration so only certain ones might be used?

Please see attached PDF for typical system configuration for clarity.


Thanks in advance for all your thoughts.

Kyle, do you have any advice?


Andre

[Ian Matthews]

I've done some fan coil units with different numbers of discharge spigots and I just did a separate family for each. Started with Type One which had one outlet, but at increasing sizes (which were included in that family), then changed the model to add another outlet, called it Type Two etc etc. Didn't take long at all. Arraying the number of outlets and incorporating different sizes just went into the too hard basket.

I think someone posted recently about having connections On of Off using a tick box, which would apply to your case, but I haven't investigated this.

And having a return air connection with no physical connection is something I am also most definately interested in. Fan coil units, air handling units, computer room units - even some VAVs all have this set up. In fact we're doing a major hospital project at the moment (in Autocad) and a lot of the supply air on various floors is finding its way back to the main plantroom via ceiling voids, light wells etc. How would I have 'connected' this in Revit?

[andre.gawlik]

Ian,

That is exactly my point!

Revit is being marketed as a design tool not a drafting tool. I could have all those things done in Autocad in a flash but with Revit one runs into trouble all the time.

You cannot model bulk of the systems we need to design because lack of logical only connections on the mechanical side of things (not sure about electrical, haven't tried it yet).

I hope we can expect significant improvement in this area very soon very soon!

Andre

[aupy]

We're facing the same issue here. We're designing a fan coil system utilizing fan coil units with non ducted return. I've been trying to find a way to design this kind of system in Revit but it looks like there must be a physical connection between the return air grilles, the outdoor air's volume control damper and the FCU return air.

Even if I decide to have it ducted, the system type of the outdoor air must be set as "Return Air" in order to connect it with the actual return air from the conditioned space. If I'm not mistaken, there's no such things as Outdoor Air, Outside Air, Fresh Air System in Revit!? I was so surprised back then

If there's no way to have a proper connection between the non ducted return FCU, the return air system and the outdoor air system, then what's the point using Revit MEP in this case? We could have done it the traditional way, make some calculations and quickly develop the plan in AutoCAD and pray that there will be no alteration in the future.

Maybe next time we design an all-air system using central AHUs or ducted FCUs with treated fresh air supplied directly into space, things will be more straight-forward.

Please correct me if I'm wrong as I'm still in the middle of learning Revit.