Revit MEP

Revit MEP
Showing posts with label calculations. Show all posts
Showing posts with label calculations. Show all posts

Friday, June 24, 2011

ElumTools - The first fully-integrated Add-in lighting software for Autodesk Revit





ElumTools is from Lighting Analysts, Inc. who produces calculation tools for the architectural lighting marketplace. Today, they author four design tools for the lighting industry: AGi32, Photometric Toolbox, FlashTools, and the newest addition, ElumTools, a fully integrated lighting calculation add-in for Autodesk Revit.

This new tool will be a much more efficeint way of doing point-by-point lighting calculations rather than importing 2D plans into AGI, creating 3D spaces and 3D objects that are representing the rooms in AGI, (which has already been done by the architect in Revit), so why redo that work?  Then as the model updates and changes, you have to redo all that work of reimporting the 2D autocad file, and recreate the 3D spaces and 3D objects.  That takes a lot of time.  Using a software that is an add-on of Revit, you can do the calculations right within Revit, and not have to continuously update separate models.  (Construction document Revit model, and the AGI lighting calculation model.)  Then when you make changes to your light fixtures, you make those changes in the Revit model only, (one place) instead of making the changes in the Revit model and in the AGI model. 

SNIP FROM THEIR WEBSITE:
The growth of BIM (Building Information Modeling) software is exploding, and in many architectural design and engineering firms it is almost completely replacing CAD software for the purposes of architectural and building system design. To date, the industry standard illumination design software programs lack the ability to easily exchange information with models in the BIM environment. The reason for this is two-fold: current illumination software utilizes a complete environment approach to the calculation of illuminance, which is burdened by the large size of the BIM model, and the complexity of exported geometry from BIM is beyond the needs of practical calculation of workplane or surface illuminance. With today’s illumination design software not getting the job done, there remains a need to quickly compute basic illuminance from electric sources within individual environments in a BIM model and tabulate the results in a way consistent with the behavior of the BIM software.

What is ElumTools?
ElumTools is a calculation Add-in used to predict the performance of electric lighting systems within the Autodesk® Revit® Architecture or MEP software. With ElumTools the need to utilize external software to compute illuminance from light sources placed in Revit is no longer necessary.
When ElumTools is installed in Revit, it appears with its own tab on the top menu bar. Selecting the ElumTools tab reveals the icons for the various ElumTools commands.
How does ElumTools work?
The entire concept of ElumTools as a Revit Add-in is based around the ability to leverage content that is already present in the Revit model. Utilizing existing content from Revit allows the lighting software functionality to be simplified to only those tasks necessary for the accurate modeling of light.
The accurate calculation of illuminance on a workplane or surface requires the following components: surface geometry, surface reflectance/color, luminaire locations and luminaire photometry. ElumTools is able to extract surface geometry in the form of “Rooms” or “Spaces” as defined in Revit Architecture or MEP, or if necessary, the user can simply select the surfaces to be included in the calculation using Revit commands. Surface reflectance and color can be interpreted from the Revit “Graphics Shading” properties of the surface and “mapped” to more suitable reflectances and/or colors if desired. Luminaire locations already present in Revit can be consumed by
ElumTools and photometric file associations created if not already present.
With these elements known, ElumTools has the information required to utilize a radiosity process to compute the lighting for the selected geometry and present an interactive visualization depicting the luminous exitance of all surfaces. However, there is an additional fundamental need to allow the user to assign calculation sampling points to any surface or workplane to verify illuminance present from the Revit layout of luminaires. This is easily accomplished using ElumTools’ Calculation Points command.
With materials mapped, luminaires defined and sampling points placed, ElumTools calculation commands enable the computation of the selected geometry. Revit-defined Rooms or Spaces can be computed alone or as a group if they contribute light to one another. The computed results can then be examined in an interactive visualization window (a separate window for each Room or Space) and point-by-point results seen directly in the Revit model. Finally, all statistics are available to Revit’s scheduling tools for summary and inclusion in the BIM model.
Anatomy of a typical workflow
Manage luminaires – This is the process of assigning all of the necessary elements to each luminaire family within the Revit model that will be used for lighting calculations. Required input includes: a valid photometric file in IES format (LM-63), assignment of a light loss factor and a validity check on lumens and watts figures as retrieved from the manufacturer’s photometric file.
The ElumTools Luminaire Manager provides simple access to the necessary inputs for all luminaire families. The luminaire list can be shortened to show only luminaire families currently in use in the Revit model, if desired.
Map materialsElumTools has access to the “Graphics Color” in Revit for all materials in the model, allowing the reflectance of the surfaces to be calculated from the RGB color.* If a Revit graphics color is not an accurate color from which to calculate reflectance, it is necessary to map that surface to a different and more appropriate color. Glass and other translucent or transparent materials must also be mapped to the appropriate surface type in ElumTools for accurate lighting calculations.
The Materials Mapping feature in ElumTools is very easy to use. All Revit materials are listed on the left side of the dialog and ElumTools materials on the right. The drop-down selection in the center allows individual materials to be mapped from Revit to ElumTools and vice-versa, or ignored entirely. Additional pull-down menus allow the selection of color, reflectance, surface transparency and more (Advanced Properties button).

*As of the release of Revit 2012, the Revit Application Programmers Interface (API) provided by Autodesk does not provide access to the materials’ “Render Appearance” information. This may change in a future release providing more accurate material color and reducing the need to map some materials.
Locate point-by-point areasElumTools makes it easy to assign a grid of sampling points to your choice of surfaces and workplanes in the Revit environment. Simply select the Calculation Points command and drop an instance of the sampling points family on surfaces as required. The points will automatically attach only to the selected Revit surface. Other surfaces such as windows or doors would not be included and could be covered with another instance of the family, if necessary. Workplane calculations are simply points on the floor with an offset equal to the workplane height.
Calculate Room or Space – Rooms and Spaces are spatial placeholders created by Revit Architecture and MEP. If the Revit model does not have Room or Space designations, it is only a matter of a few clicks to add them.
ElumTools allows the calculation of either Rooms or Spaces using a single or multiple selection technique. When selecting multiple Rooms or Spaces, ElumTools allows multiple calculations to be performed simultaneously on multi-threaded processors. If separate environments may exchange light with one another, they can be computed in a single execution.
Calculate Other Geometry – Occasionally it is necessary to select all the elements to be included in a calculation independently of Revit Rooms or Spaces. ElumTools provides the capability to select all elements to be considered manually using Revit commands and compute the propagation of light within this subset.
Interactive visualizationElumTools provides a fully interactive visualization in a pop-up window as a by-product of every calculation. This rendering is designed to allow validation of lighting results (are all my luminaires included?) and a verification of the behavior of light and surface (scalloping from downlights on an adjacent wall). The visualizations are fully navigable, and additional evaluation tools are available, such as scaled pseudocolor analysis, radiosity mesh display and visibility of sampling points.
View point-by-point results in Revit – The illuminance values at all sampling points placed in the Revit model can be seen directly in Revit. The appearance of the value color can be changed using Revit’s Analysis Visualization Framework (AVF) to scale the gradient of illuminance values for improved readability.
Schedule – All illuminance statistics computed by ElumTools are available to be summarized with Revit’s schedule feature.
Exceedingly simple & efficient
The concept of computing the lighting results directly within the Revit environment using a Space by Space (or Room by Room) methodology fosters a fast and efficient workflow, removing the long calculation times associated with the whole-environment approach of external software. Designers can utilize the software as a design tool on an iterative basis as needed. Point-by-point results provide validation of required lighting criteria, and interactive draft visualizations yield an understanding of the lighting system only possible with radiosity rendering.

Unlike many of today’s all-encompassing lighting simulation programs, the ElumTools software is exceptionally intuitive, streamlined and approachable. By design, the software can be productive for any Revit user with basic lighting knowledge, and very little if any training is required.

ElumTools Licensing
For the initial release ElumTools is available in a single user license configuration only. A single user license can be installed on one computer at a time. Once registered, ElumTools is licensed to that computer only. This is a perpetual license for use with Revit 2012 only.

Subscription Plan
ElumTools is sold initially with a free one-year membership to the subscription plan. This means all product releases are available for download from your account at no charge until one year from your purchase date. At that point you may elect to renew the subscription plan to continue to receive product releases.

Friday, October 01, 2010

Autodesk® Green Building Studio® web-based energy analysis software

Autodesk® Green Building Studio® web-based energy analysis software can help architects and designers perform whole building analysis, optimize energy efficiency, and work toward carbon neutrality earlier in the design process. With faster, more accurate energy analysis of building design proposals, architects and designers can work with sustainability in mind earlier in the process, plan proactively, and build better.
  • Whole building energy analysis software—Determine virtual building’s total energy use and carbon footprint
  • Design alternatives analysis—Consider alternatives to improve energy efficiency
  • Detailed weather analysis—Extensive weather data available for project site
  • Carbon emission reporting—Emissions reporting for nearly all aspects of the building
  • Daylighting—Qualification for LEED® daylighting credit
  • Water usage and costs—Estimated water use, in and outside building
  • ENERGY STAR® scoring—Scores provided for each design
  • Natural ventilation potentialSummarizes mechanical cooling required and estimates hours design could use outdoor air to cool the building naturally



Autodesk Ecotect Analysis includes innovative building energy and carbon analysis tools made available through the Green Building Studio web-based service. The web service provides a user-friendly front end to powerful building energy analysis software. All of the computationally intensive hourly simulations are carried out on remote servers, and the results are provided to you in a web browser. The web-based service will collect data from three sources:

  1. Your Revit® software model. All the building geometry comes from your model, including the number of rooms, the connections between rooms, and their relationship to the exterior, exposure, and aspect to the sun; and the shape and total area of built surfaces or openings.
  2. Your responses to a few basic questions. In order to explain the building’s use or context, you will need to select a building type from a drop-down menu and enter the project location. You will also have a chance to select a weather station for the project, although the closest one is selected to be the default.
  3. Regionalized databases. Based on the above information, the Green Building Studio web service will extract additional information about local weather conditions, construction, and materials. The service will automatically add any information you have not provided, so it can adapt to your requirements as your design evolves.
 
Autodesk® Ecotect™ Analysis 2010 software is a comprehensive concept-to-detail sustainable design analysis tool, providing a wide range of simulation and analysis functionality through desktop and web-service2platforms. Powerful web-based whole-building energy, water, and carbon analysis capabilities converge with desktop tools for visualizing and simulating performance of the building model within the context of its environment. Use the desktop tools and web-service functionality together to help create more sustainable designs. This document describes how to access your Green Building Studio web-service account and manage projects, and provides tips to help you get started.

Tuesday, June 01, 2010

Pressure Drop Calculation

I got an call from a client last week asking about some of the calculations that Revit MEP does.


I am trying to get results for Duct Pressure drop in Revit MEP.



Can you please share your ideas, as how can I achieve this?

This post has some additional information but is based on the Revit MEP calculation white paper from Autodesk.  Revit MEP Duct Sizing calculations

Revit MEP computes pressure losses in ductwork based on the geometry and roughness of the ductwork, air

density, and air viscosity. Values for Air Density and Air Viscosity are specified in the Mechanical Settings.


Roughness is specified in the type properties for duct/duct fitting component families.
 
 


The following example shows how Revit MEP calculates the pressure drop for a 100 foot segment of 36"x24" duct carrying air flow of 12,000 CFM.  Pressure drop is defined as:


This values checks with the Hydraulic Diameter parameter shown in the Properties of the Duct in Revit:


The velocity is based on the cross sectional area:


After determining the friction factor, the pressure drop can be calculated:


The value for the calculated pressure drop matches the value found in the duct’s properties in Revit MEP.

Tuesday, August 18, 2009

Revit MEP Calculations. How'd They Do That?

Ever wonder what's inside the black box of Revit? What standards and methods are being used in their calculations? Can I trust them. Well, in the past I would just compare my calculations to Revit's calculations to see if they were close.

Pipe Sizing
You use the Pipe Sizing dialog to automatically specify the sizing for sections of pipe using friction and/or velocity sizing methods.

Fixture Units to Flow (GPM) Conversion
Revit MEP provides a general conversion from fixture units to flow, using the values found in the 2006 International Plumbing Code (IPC), Table E103.3 (3). The flow conversion method selected in the Instance Properties dialog for the selected system determines the section of the IPC table used for the conversion. The resulting flow is used to calculate pipe sizing.

The value calculated for flow can be helpful in sizing the branch piping for subsystems. However, when specifying sizes for the main piping, you should consider a variety of other factors, including the type of system, the type of building, peak demand, available supply pressure, the pressure required at the highest fixture, and limitations imposed by local authorities, selected fixtures, and supply source. The 2006 International Plumbing Code, Appendix E provides detailed information that must be considered when planning a plumbing system

Autodesk is working on releasing more documentation on how the data is calculated.

The PDF documenation is in beta. You can download the file at:

Revit MEP electrical wire sizing calculations
Revit MEP Duct Sizing calculations

Revit MEP_Hydronic_Piping calculations