Ability to undertake simulations to determine the impact of daylight use to offset use of artificial lighting in a building.

Task

Instructions

1. Access a simple exemplar and explore the model.

Return to your home folder and start up ESP-r. From the top level menu, choose open existing and then exemplar options and select the base case cellular model from the technical features category. Copy the model into your home directory.

Explore the basic features of the model by selecting browse/edit/simulate, then composition. View the geometry, constructions and operations files for the model.

2. Define a change in lighting loads between the two offices.

Return to the Project manager->browse/edit/simulate->composition menu, and select the operational details option. At present, a lighting gain of 10W/m² has been defined for both offices during weekdays working period and Saturday morning. Select the manager_b zone. Set the lighting in this office to zero on weekdays and Saturday.

3. Run a winter simulation and determine the impact of lights on the heating requirements.

Return to the Browse/Edit/Simulate menu. Run a simulation for a winter week (the default period).

Run the results analysis. Look graphically at the dry bulb temperatures and heating load in the two offices over the simulation period. Then find the total heating requirement and number of heating hours for the two offices by returning to the results analysis menu and selecting enquire about. The heating load in the manager_a zone should be lower than that for manager_b - why is this the case?

4. Undertake a summer simulation and determine cooling requirements.

Repeat the simulation but change the period. In the simulation controller menu, select simulation presets and choose the summer week and undertake a simulation.

In the results analysis, look graphically at temperatures and cooling loads, and find the total cooling requirement and number of cooling hours for the two offices by returning to the results analysis menu and selecting enquire about.

Restore the lighting in the manager_b office by editing the file in the operational details section. Simulate the model again and check that the results are now the same for both zones. Alternatively, you could reload the original model.

5. Define a lighting control scheme and determine its effect on plant loads

Return to the Project manager->browse/edit/simulate-> composition menu, select the casual gains control option, and select the manager_a zone, then create.

Define a single lighting zone control where the sensed illuminance is calculated by a user defined daylight factor as follows:

1. Set the control period to 0-24.
2. Set the calculation type to User defined DF.
3. View the control data.
4. Define the photocell location (option m) as 1.50 2.25 2.80 0.00 0.00 -1.00 i.e. the centre of the ceiling, facing down.
5. Finally, for the outside glazing (labelled glazing in the source surface section) set the daylight factor to 0.1145. This means that the photocell responds to a daylight factor of 11.45% on the working plane (i.e. 11.45% of the external horizontal illuminance) - the information has been obtained from a separate detailed lighting study.

IMPORTANT - remember to save your control information as you will not be reminded and the information will be lost if you exit before you save.

Simulate the model for winter, spring and summer periods and note the effect of lighting control on the heating and cooling demands in the manager_a compared to the manager_b office.

6. Define lighting control scheme with multiple lighting zones

Return to the Project manager->browse/edit/simulate->composition menu, select the casual gains control option, and select the manager_b zone, then edit.

Define two lighting zone controls (a core zone and a perimeter zone) where the sensed illuminance for each zone is calculated by a user defined daylight factor. For the perimeter zone:

1. Set the control period to 0-24.
2. Set the calculation type to User defined DF.
3. For the photocell data define the proportion of the gain as 0.5.
4. Move the photocell to 4.50 1.125 2.80 0.00 0.00 -1.00 i.e. the centre of the office perimeter area on the ceiling, facing down.
5. Finally for the outside glazing set the daylight factor to 0.1761.

1. Set the calculation type to User defined DF.
2. For the photocell data define the proportion of the gain as 0.5.
3. Move the photocell to 4.50 3.375 2.80 0.00 0.00 -1.00 i.e. the centre of the office core area on the ceiling, facing down.
4. Finally for the outside glazing set the daylight factor to 0.0449.