10.0 Annual Analysis

The final Annual Analysis screen reports a variety of annual performance calculations. Some of the calculations are essentially the same as those performed on earlier screens for the representative days except now they are run using an expanded set of ‘Design Day’ calculations, as discussed in the SPOT Development Report, and for each 8760 hours of weather data. This provides a more accurate analysis of the photosensor system since it now takes the climate conditions, schedules, and time of the day into account – i.e. coincident load type issues. Several sets of results are displayed on this screen. The user can utilize Excel’s print functionality to print any reports desired.

Annual Results At the top of the Annual Analysis screen is a table of the annual results as shown to the right. The table to the left lists the average light output, electric savings, heating load, cooling load, and average, minimum, and maximum illuminance for each zone individually and all zones together. Next to this table are some additional Building / Campus Information inputs. Here, the user specifies a multiplier that is used to calculate savings for a group of similar spaces and the blended utility rates for electricity and gas.

Building-Wide Results The table to the right provides building wide results for overall energy and energy cost savings. The total building wide energy related cost savings are provided at the bottom of this table. Remember, energy savings is only part of the equation for daylighting. Benefits related to productivity, well-being, health, enhanced learning environments, and increased retail sales should be considered and completely outweigh the energy saving benefits of daylighting.

The Daily Results chart provides a variety of performance information for the combined daylighting, electric lighting, and control system design for every day throughout the year. These results are useful in identifying seasonal variations in the daylight performance.

The Hourly Results chart provides a variety of performance information for the combined daylighting, electric lighting, and control system design for every hour of average monthly performance. These results are useful in identifying hourly, morning to evening, variations in the daylight performance.

The Detailed Results chart provides a variety of performance information for the combined daylighting, electric lighting, and control system design for every grid point throughout the space. These results are useful in identifying any locations in the space that underperform.

The CX Report button opens up the Commissioning Report pages. These can be used to print standard information regarding the photosensor system location and settings that can then be used in the field to assist in the commissioning of the actual photosensor systems.

The DOE-2 Schedule and the EnergyPlus Schedule buttons generate output files that can then be imported into the DOE-2 or EnergyPlus whole building energy simulation programs. In this way, the detailed lighting performance calculations from SPOT can be integrated into a more detailed model of the entire buildings energy systems.