Buildings.ThermalZones.Detailed.FLEXLAB.UsersGuide
User's Guide
Information
The Buildings.ThermalZones.Detailed.FLEXLAB package contains models of rooms, wall constructions, window
constructions, and examples demonstrating their use. These models are
created to match the FLEXLAB architectural drawings.
Use of FLEXLAB models
FLEXLAB models are made based on architectural drawings of individual rooms. The room models are located in the Buildings.ThermalZones.Detailed.FLEXLAB.Rooms package. The intent is that simulations of FLEXLAB test cells are created by connecting the necessary room models for the desired application.
The wall and window constructions in the models match the walls and windows installed during the initial FLEXLAB construction. The data records for walls can be found in Buildings.ThermalZones.Detailed.FLEXLAB.Data.Constructions.OpaqueConstructions. The data records for glazing systems can be found in Buildings.ThermalZones.Detailed.FLEXLAB.Data.Constructions.GlazingSystems.
One example demonstrating the use of FLEXLAB models is Buildings.ThermalZones.Detailed.FLEXLAB.Rooms.Examples.X3AWithRadiantFloor. The example is made assuming that the shading position controls, internal gains, air handlers, and central plant do not need detailed models. Instead it is assumed that experimental data is available and data tables reading that data are used instead.
Each room model is made to match architectural drawings. If a construction needs to be changed to match an experiment the construction definition can be changed in the Parameters window. Sometimes constructions are used in multiple walls, so the user must be careful to avoid accidentally changing the construction of more walls than intended. Detailed editing of a model may be necessary.
All FLEXLAB room models are created by extending the Buildings.ThermalZones.Detailed.MixedAir model. This model contains several ports which must be used to describe the heat transfer into and out of the space. The ports are described both here and in the documentation for Buildings.ThermalZones.Detailed.MixedAir. The following table describes the available ports:
| Name in icon | Name of connector | Physical significance |
|---|---|---|
| u | uSha |
Shade control signal. 1 = closed shade 0 = open shade |
| q | qGai_flow |
Internal gains vector with elements [1] = Radiant in [W/m2] floor area [2] = Convective in [W/m2] floor area [3] = Latent in [W/m2] floor area |
| surface | surf_surBou |
Models walls of the room with the construction represented externally. The connection represents heat transfer from the surface (represented by a separate model outside of the room model) to the air in the space. The air in the space must be described within the room model. An example of this could be a description of the floor area within the room model, connected to a model of a radiant slab modeled outside the room model. |
| boundary | surf_conBou |
Connects to rooms with a shared wall. The wall is modeled in this room, and connects to the air in the other room. The area of the air gap in the other room must be described in the other model. |
| air | heaPorAir |
Heat port connecting directly to the air in the room. |
| radiation | heaPorRad |
Heat port for radiative heat gain and radiative temperature. |
| fluid | ports |
Fluid ports that connect to the air volume inside the space. These ports are typically used for air conditioning inlets and outlets, and for air infiltration when connected to the outside air. Note that mass is conserved, hence the thermal zone cannot only have air inflow but must also have a means for air to leave the room. |
For an example demonstrating how many of these ports are used, see Buildings.ThermalZones.Detailed.FLEXLAB.Rooms.Examples.X3AWithRadiantFloor.
Future Work
A list of items which still need to be understood and finalized is below:
- The construction of the floors in the closets and electrical rooms is still uncertain. It is clear from the drawing on M3.02 that they are not heated/cooled using the radiant system. However, I have been unable to determine what the construction is. Currently the closet and electrical room floor models are using the same construction as the test cell radiant slab.
- Does HVAC serve the closets and electrical rooms?
- Identify all detailed door constructions when detailed specifications are available.
- Use available window information to identify detailed model-level window specifications.
- Create FLEXLAB-specific weather data file for taking weather data from the FLEXLAB weather sensors.
- The design of the radiant slab is not clearly documented. The model of the radiant slab should be carefully checked when the design information is available. Specific inputs which must be checked include: disPip, m_flow_nominal, iLayPip, construction for pipe, fluid flowing through the slab
- Check available air and water flow sensors. The example model Buildings.ThermalZones.Detailed.FLEXLAB.Rooms.Examples.X3AWithRadiantFloor assumes that several temperature and flow measurements are available. Are they? If not, how does the model need to be changed?
- Ventilation assumptions used in Buildings.ThermalZones.Detailed.FLEXLAB.Rooms.Examples.X3AWithRadiantFloor include zero ACH in the electrical room overnight. Probably not realistic. Electrical equipment will need cooling overnight. Try to estimate convective heat gains from electrical equipment and identify an air flow rate to keep temperature in space realistic.
- The specific construction information for the roofs is not currently available (9/5/13). Roof construction packages in Buildings.ThermalZones.Detailed.FLEXLAB.Data.Constructions are based on comments on A2.01 in the drawings. These constructions should be revisited when detailed information is available. There is currently no construction for test cell UF90XR-B because the comment in the drawings merely says "ANNUAL NET-ZERO".
- Is east wall of UF90X3B actually made using Construction18? Yes according to drawing on A2.03, but Construction18 is typically a cell or bed dividing wall and UF90X4 is no longer in construction. Has construction been changed since UF90X4 removed from plan?
- According to the drawings on M3.02, each test cell has four different sections of radiant tubing in the slab. To account for this, models of X3A and X3B use four different surBou definitions to define four different sections of the floor. Unfortunately, the total area described in drawing M3.02 (623 sq ft). does not match the floor area in drawing A2.03 (656.25 sq ft). The areas listed on M3.02 have been increased by the percent difference in the total. This assumption should be checked against final, as-built drawings when they are available.
- Length of tube in each radiant slab model in the examples is based on the numbers in drawing M3.02. These numbers may include tube running to/from the manifold, instead of only the tube in the slab itself. Worth determining?
- The heat conduction through the steel beams is not explicitly modeled. During model calibration, an effective heat conductivity would need to be identified.
Extends from Modelica.Icons.Information (Icon for general information packages).