You can use the spot elevation tool to tag the Top Of Pipe (TOP) and Bottom Of Pipe (BOP). With a little configuration of the types, you can annotate the top and bottom of the pipe elevations with an appropriate prefix.
You can add dimensions to pipes in 3D views. By creating reference planes for your pipe annotations and adjusting your workplane, you can place the dimension lines adjacent to the pipes. By constraining the reference planes to the pipes, you can keep the dimensions aligned with the pipes, even if the pipes move.
The conduit catalogs in AutoCAD MEP include sizes up to 6" for Aluminum and Galvanized conduit, however, the default part routing preferences only allow routing of sizes up to 4". This is because the transition fitting in the preference is only avaialble up to 4", and therefore, restricts the available sizes.
If you remove the transition from the preference (or modify the transition to include sizes up to 6") you can then route 6" conduit.
The embeded video demonstrates how to modify the preference to remove the transition. Note that it is likely you will need to save/close/reopen the file after modifying the preference.
I was recently asked where the default values for lighting loads and power loads come from. These default values are found on Spaces when you inspect them using the Heating and Cooling Loads tool, and when you directly inspect the Space in the model.
The short answer is that they come from the settings in Manage > MEP Settings > Building/Space Type Settings.
By way of an example, if the Space has its Space Type set to <Building>:
The Building Type is Specified in H/C loads dialog (or in Manage > Project Information > Energy Settings)
The Building Type has a set of properties in the Building/Space Type Settings window.
These settings are referenced when you are running a load, or checking things such as the Electrical Loads settings on a Space.
Recently, I was asked how one might constrain a connector width in an instance parameter to be less than the width of solid it is hosted on. In the specific case, there are two solids, one representing the main body of the equipment, and the duct 'collar' on which the connector is hosted. The duct size must match the collar, and the collar must stay smaller than the equipment.
The formula below to control the collar size works just fine... however, when you select the family instance in the project, you can use the blue numerical control to set the connector width to something larger than the geometry... as you can see from the formulae, there is are no constraints on the actual duct connector sizes.
The problem is one of validation, not constraints/dimensions. As you can see in the revised parameters below, there are a couple of checks to make sure the duct size stays smaller than the section size. If the duct is modified to be bigger than the body, we force the collar length to 0, which Revit will not allow, and a error to the user will force them to undo the invalid setting.