Criteria for Creating Your Own Families of Hangers/Supports
Last updated
Last updated
If you can't find the required product in our provided library of Revit families of hangers and supports, you have the option to create your own families. These will automatically resize when inserted using the MEP Hangers software if they are created correctly. In this article, I will outline the standards for creating families for MEP Hangers. Additionally, these standards can be used against your current library of hanger families to check if they are compatible with our software.
Some important points to note:
Intermediate knowledge of Revit families is required.
There are multiple ways to create Revit families; this is not a step-by-step guide but rather a set of requirements, guidelines, and tips.
If you need to create new sizes for existing families (e.g., rods, unistruts, clamps, etc.), refer to another article covering that specific topic.
Creating everything from scratch is often unnecessary. You can use a complete hanger family as a template and modify only the necessary component (e.g., a clamp) before integrating it into the template family. Other components (like rods and anchors) may remain unchanged or require minimal adjustments.
Our Revit families of hangers and supports consist of smaller components (bolts, nuts, washers, unistruts, rods, clamps, etc.) organized as nested families. This article will focus on complete hanger families rather than the components within.
The primary requirement is that the family must be created as a face-based family, allowing its use for various applications.
You can start by modifying our provided families as they are already face-based or, if starting from scratch, use the provided template:
If unsure whether your existing Revit family is face-based, you can check that here:
For internal components (nested families), there are no specific criteria, as they are typically controlled through associated parameters within the parent family. However, being face-based often proves beneficial, though not mandatory.
MEP Hangers can insert elements from these categories: Duct Accessories, Pipe Accessories, Electrical Equipment, Generic Model, Mechanical Equipment, Structural Connections, and Structural Framing.
But when choosing a category, there are more things to consider. If you will need to create multi-level structures, it’s important to look at structural elements that MEP Hangers software can find to attach the hangers to.
These categories include Structural Framing, Structural Connections, and Mechanical Equipment.
Alternatively, if using nested elements, the family can be from Duct Accessories, Pipes Accessories, Electrical Equipment, or Generic Model, with nested elements from Structural Framing, Structural Connections, or Mechanical Equipment categories. This way, you can have more flexibility to choose your category but it will still work for multi-level arrangements.
We recommend creating hanger/support families using Mechanical Equipment, Structural Framing, or Structural Connections categories.
Elements of the Mechanical Equipment category are visible floorplans even when above the cut plane which can prove helpful as well.
Next, we look into the required parameters.
Our software sizes each hanger by extracting data from the MEP element and measuring the distance from the MEP element to the specified structural element.
To read data from MEP elements, create instance parameters with names corresponding to the relevant property ('Diameter', 'Outside Diameter', 'Width', 'Height', 'Insulation Thickness') and group these parameters under the Model Properties group:
The example above shows a pipe support so the Width and Height values aren’t needed here.
Values will not be populated if these parameters are grouped under a different group.
It's advisable to create these parameters as Length-type parameters under the Common discipline:
These values populate when the Insert or Update commands are executed. This ensures that a clamp or a horizontal metal member sizes according to the MEP element's size.
To size a vertical hanger member (rod, unistrut, etc.) according to the distance from the structure, use the 'Distance To' parameter. This is an instance length-type (Common discipline) parameter which must be placed under the Construction group:
When the Insert or Update commands are executed, the software calculates the distance from the hanger insertion point to the structure and writes that value to the 'Distance To'.
The hanger insertion point, from which the 'Distance To' is calculated, is specified in the configuration ('Placement Side' setting).
If a pipe or duct is insulated, the hanger insertion point is the pipe/duct edge, not the insulation.
However, this alone doesn't size the hanger. The 'Distance To', 'Diameter', 'Outside Diameter', 'Width', 'Height', and 'Insulation Thickness' are usually processed through a formula in a different parameter that influences the geometry or the nested families.
For instance, in one of our hanger families, the 'Distance To' value drives the 'Rod Top Extension' parameter:
Our calculations account for many more parameters to make hangers work in diverse situations. Your formulas can be simpler and still be effective.
Finally, the 'Rod Top Extension' parameter drives the 'Top Extension' parameter, controlling the geometry of the nested rod family:
This is just an example. Your hanger families may contain no nested elements, and the geometry can be controlled directly.
The MEP Hangers software can also measure the distance from MEP to the structural elements in directions other than upward. This capability enables the utilization of the 'Distance To' parameter for various applications, such as rooftop supports or wall hangers.
MEP Hangers can also extract additional values from MEP or structural elements and incorporate them into families of hangers.
This can be accomplished through the use of the # and ## functionality.
To extract data from structural elements and write it to hanger families, create a family or a system parameter with a name corresponding to the relevant property and add '##' at the beginning of the parameter name. This new parameter must be an instance parameter and must be grouped under the Construction group.
For instance, consider a multi-level hanger structure where each unistrut is of a different size, controlled by a 'b' type parameter in the unistrut family.
The software populates the '##b' value, driving the position of washers and hex nuts in the hanger family. This ensures that washers and nuts are positioned precisely at the top and bottom of the unistrut automatically, regardless of the unistrut size.
The type of the parameter, whose value is being read, must match the type of the destination ## parameter. In this example, 'b' is a Common/Length-type parameter, so '##b' must be of the same type.
In the example, the software attempts to read the 'Slope' value, but the unistrut family lacks such a parameter, resulting in no returned value (defaulting to 0.00°).
This functionality enables hangers to be automatically sized according to the structural element size.
A similar workflow can be applied to extract any parameter for MEP elements. The only differences are that only one '#' symbol is needed before the parameter name, and the parameter must be grouped under the Model Properties group.
The # and ## functionality extends to text-type parameters as well. Ensure that the Discipline and the Type of the parameter match:
This functionality proves valuable for scheduling in Revit, as it can extract useful parameters from hosts (MEP elements) or structural elements.
Use the '#Family Name' parameter to distinguish which MEP service each hanger has been placed on.
To control the visibility of hangers in your Revit views, create the '#System Name' project parameter and assign it to the category of your hangers. This will populate values from each MEP element, and system parameters can be used for view filters, making it easier to filter out unwanted hangers.
If you already have a collection of hangers you want to use with our software, the key is to make sure they're face-based. This makes it easier to align them with MEP Hangers standards. If they're not face-based, you'll need to recreate them in this format. Depending on how they're built, starting with one of our hangers and adjusting the needed components might be simpler.
If you're starting from scratch without a library, the recommendations are quite similar: begin with an existing family and modify it as needed. Regularly import the family into the project, even if it's not finished, to ensure everything works as expected. You can also start with an empty template if you'd like to create it without the constraints and parameters of existing families.
Before diving into creating or modifying families, consider that our provided hanger/support families are designed for customization; they might already meet your needs. Check out these two articles on our families for more guidance: Introduction, Features, and Functionality and Adding New Sizes for Unistruts, Rods, Cantilevers, or Other Parts.
