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To use this feature, you must sign in to Autodesk web services by clicking
Services Sign In, and entering the User ID and password associated with your Autodesk account.
In the Energy Settings dialog, these settings affect the results of a conceptual energy analysis performed on a mass model visible in a 3D view.
These settings do not affect a detailed energy analysis performed using heating and cooling loads in Revit MEP
or by exporting the model to gbXML
Building Operating Schedule
Specify the operating schedule for the building. This setting overrides the default operating schedule, which is based on the selected building type.
This schedule can have a significant impact on the energy results. Choose a schedule that most closely matches the building’s assumed hours of operation.
Specify an HVAC system for the project.
If the project goal is a carbon-neutral building, include an HVAC system only after optimizing all other features of the building.
To design a carbon-neutral building, consider the following strategies:
- Design the building form, mass, and openings to take full advantage of natural ventilation and daylighting opportunities.
- Use electric lighting only in spaces where the natural light is insufficient and during hours without sun.
- If possible, make use of ceiling fans. With an air movement of about 150 fpm (1.7 mph), a person will experience the same level of comfort with the air temperature 3-5°F higher than a space without air movement.
- Incorporate thermal mass and evaporative cooling if appropriate for the weather and building use, and only use compressor cooling as a back-up or on design days.
This effort requires coordination between the architect, the mechanical engineer, and, if window sensors are included, a controls contractor. Include the owner in the effort if the definition of comfort is to be explained and discussed.
It is more challenging to predict and design for comfort in a mixed mode or naturally ventilated building than it is to specify rooftop units that are sized to keep a space at 74° F.
Outdoor Air Information
In the Energy Settings dialog, click Edit to display the Outdoor Air Information dialog, and specify the desired settings.
If you select multiple options for outdoor air in one analysis, the simulation tool automatically calculates the largest outdoor air volume and uses only that category in the analysis.
|Option ||Description |
|Outdoor Air per Person ||The rate of outdoor air exchange measured in terms of CFM (cubic feet per minute) per person. |
|Outdoor Air per Area ||The rate of outdoor air exchange measured in terms of CFM per square foot of occupied floor area. |
|Air Changes per Hour ||The number of times in one hour that the total volume of air in the building is replaced with outdoor air. |
Outdoor air rates must balance competing needs for indoor air quality against energy efficiency. Depending on weather conditions, when fresh outside air for ventilation is introduced into the building, energy is required to heat or cool the air to the target indoor air temperature.
Typically, most energy codes have specified a minimum of 15 CFM (cubic feet per minute) per person of outside air. Some building uses require greater volumes of ventilation air, such as laboratories.
Consider the use of demand ventilation systems, which measure the levels of CO2 in the air and provide outdoor air accordingly for a more energy-efficient solution than constant outside air.