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When doing either of these, you need to specify the building geometry and the building spaces. All spaces need to be assigned a space function. If doing envelope and lighting compliance (NewEnvelopeAndLighting selected for the Compliance Type on the Project input screen) you need to input the details of the proposed lighting design. If doing envelope only compliance (Compliance Type set to NewEnvelope) then the default lighting power density data for the space functions should be left in the model – any user entries will be replaced.

In either case, you do not need to specify any HVAC systems. However, you do need to add Thermal Zones on the Mechanical tab, and assign spaces to thermal zones. Thermal zones are required to allow the rules to assign HVAC equipment for the proposed and baseline models.

When compliance analysis is performed, the proposed model will use the user specified envelope. For envelope only compliance, the proposed and baseline models will use identical interior loads, using the default values assigned to the space functions being used. For envelope and lighting compliance, the baseline will use the default lighting power while the proposed model will include the user supplied lighting system. For both compliance types, the HVAC system type will be the same. The rules used to define and size the baseline system for a complete building analysis will be used for both the baseline and proposed models. Sizing of the proposed may be different due to differences in heating and cooling loads due to differences in the envelope and lighting systems.

Use the selection tool to select a line segment of the surface that needs to be removed and then use the eraser tool or press the delete key. Then redraw the correct surfaces or subsurfaces.

When working on a model with the OpenStudio plugin in Sketchup, the model data exist in OpenStudio with the portions being displayed existing in Sketchup as well. Problems can occur if the data in the two programs get out of sync. When a new surface or subsurface is created in Sketchup, OpenStudio makes default assignments to the surface such as the construction type. Since several steps were taken all at once, the undo function is not able revert the model multiple steps to remove the newly created surface. The Sketchup representation will look fine, but no longer matches the underlying OpenStudio data. It is recommended that you never use “Undo” when working on an OpenStudio model in Sketchup.

In addition, the model should always be saved and opened with the OpenStudio plugin by going to the menu Plugins->OpenStudio->File or by using the Open and Save buttons in the OpenStudio toolbar. All model files should end in .osm not .skp. Do not use Sketchup file menu commands when working with OpenStudio Models.

Lights can be defined as a lighting power density or within a lighting system. The lighting system method allows the entry of luminaire types and the quantity of each type in the space. Each lighting system can be assigned to a daylit area type for use with daylighting controls: Skylit, the portion of the floor that receives daylight from a skylight; Primary Sidelit, portion of the floor that receives the highest amount of daylight from a window; Secondary Sidelit, portion of the floor that receives a lower, but still useful, amount of light from a window; or none for that portion of the space which is not daylit.

CBECC-Com determines daylit zones from the geometry of the space and the locations of skylights and windows when valid fenestration constructions have been assigned. When lighting power is above 120 W in a daylit zone, daylighting controls are required. Daylighting inputs include the amount of lighting controlled and the daylighting control type. Three types of controls are available: Continuous, Continuous Plus Off, and Stepped Switching. The Continuous controls can operate at any fraction between the minimum and maximum power output. With the Continuous Plus Off controls, the minimum power output is zero. The Stepped Switching controls changes the lighting power output in discrete uniform steps.

When the simulation has more than 150 hours of unmet load hours, the HVAC system capacities must be manually increased to meet the load. Remember to increase both airflow and coil capacities. There is an exceptional condition that should be marked “Yes” when this is done, and a note will be added to the compliance report.

A so-called “non-convex” space or zone is one where one or more surfaces cannot “see” one or more of the other surfaces in the space or zone. A common example would be an “L” shaped zone. If EnergyPlus is run with “Solar Distribution” set to FullInteriorAndExterior, a zone like this will create errors. However, CBECC-Com runs the EnergyPlus models with Solar Distribution set to FullExterior. In this case, beam solar radiation entering the zone is assumed to fall on the floor, where it is absorbed according to the floor's solar absorptance. Any radiation reflected by the floor is added to the transmitted diffuse radiation, which is assumed to be uniformly distributed on all interior surfaces. Non-convex spaces or zones do not create problems when FullExterior solar distribution is used.

Terminal units are required by EnergyPlus as the connection between an air system and a thermal zone. In your case the terminal units would have a type of "Uncontrolled" and corresponds to the grill through which supply air enters the space.

In the Space Data tab under Electric Use, Ltg. Specification choose TailoredMethod from the drop down. Specify general lighting power in the space either by the LPD method or by building an InteriorLightingSystem for the space. If you want to claim for additional allowances allowed with the Tailored Method, choose the Allowance Type from the TailoredMethodAllowtype dropdown in the Interior Lighting System Data tab. Based on your selection, enter the length or area covered by the lights in the allowance.

In CBECC-Com interior lights can be modelled by either simply specifying the lighting power density, or by building up a detailed lighting system. PAF credits can be claimed only with the InteriorLightingSystem method. Within the Interior Lighting System Data tab, choose the PAF credit type applicable for your lighting system from the drop down menu. The software will auto populate the PAF fraction and adjust the total lighting power based on the selection.

For a compliance analysis, all schedules used are defined by the ACM. Any schedules defined or assigned by the user will be ignored. User schedules will only be used when the software is run in research mode.

You will need to select a material from the library with similar thermal properties to the material being used. You can find the material library in spreadsheet form as part of the CBECC-Com installation in the C:\Users(your username)\Documents\CBECC-Com 2013 Data\Documents\RulesetSource\CEC 2013 Nonres\Rules\Tables folder of your computer.

If the project has below grade surfaces that form a basement or at grade surfaces that form a slab, the following steps should be taken in the Open Studio Plugin to prepare the model for CBECC-Com:

1. In OpenStudio using the Inspector tool, under Constructions, create a new CfactorUndergroundWall and/or a new FfactorGroundFloor (there is no need to fill in the Construction details for these because they will need to be entered into CBECC-Com later)
2. Double click on the model / space that has the below/at grade surfaces
3. Select one of the below grade or at grade surfaces
4. In the Inspector tool the OS:Surface dialogue box for the surface you have selected will come up on the right panel
5. Set the Outside Boundary Condition to Ground, Sun Exposure to NoSun, Wind Exposure to NoWind, and assign the appropriate Cfactor or Ffactor construction that you just created to the the surface's Construction Name
6. Repeat steps 3-6 for the remaining below / at grade surfaces.