With cove.tool users can specify the months, days, and hourly usage of their project with the detailed Occupancy Schedules feature. Before we begin, remember to hit the recalculate button after making changes to schedules. Switching tabs and editing other inputs before saving will erase the changes made to the schedule's table.

Overview

Occupancy rates vary from building-to-building, system-to-system, and are meant to best predict energy consumption and expenditure as needed to support occupant activity. Therefore, occupancy rates are one of the factors that most contribute to high energy usage. To better simulate the unique activity for a project, users can input the performance of systems at the two extremes of occupancy (occupied and unoccupied hours), and control the intensity of the system over a time table, as shown above.

What factors are controlled by the schedules feature?

The interactive schedule controls five key inputs for the energy model:

  1. Lighting

  2. Appliance Use

  3. Occupant Density

  4. Heating (indirectly)

  5. Cooling (indirectly)

Occupied and unoccupied hour percentages are specifically linked to lighting, appliance, and total occupant hours. Each of these inputs is divided into occupied and unoccupied hour rates. The occupancy rates will be inputted on the right and will be the intensity used for the energy model based on the distribution of hours and percentage of the schedules to the right.

  1. Occupied Hours are when the building is heavily used. For example, a typical office building will typically require the most mechanical support during 8am-5pm on weekdays when office workers and building staff are most likely using the building. The maximum number of occupants per occupied hour is based on the Total Occupants (Occupied Hours) input.

  2. Unoccupied Hours are periods of time where the primary activity is not dominant to its function but might require some people to access the building for other reasons. For example, the summer or winter break for schools or late at night when everyone goes home from the office. The minimum number of occupants per occupied hour is based on the Total Occupants (Unoccupied Hours) input.

How to use it the schedules time table

Setting the schedule requires the selection of dominant months, days, and hours for the building occupancy.

  • Months and Days can be selected by clicking on any of the rectangular buttons to change its color. Any blue button represents the time associated with occupied hours. Any white button represents the time associated with unoccupied hours.

  • Hours are represented by vertical bars broken into 10 squares as 10% fractions of each hour. Each percentage of an hour can be selected by clicking on or click-and-drag along the squares in each vertical bar to change its color. Blue represents occupied, and white represents unoccupied.

Unoccupied Months

Let's start with the Unoccupied time periods. These are deselected months that are white. For all days and hours on these deselected months, the occupancy percentage is set to a default of 10%. No other scheduling inputs change the value for these months.

Occupied Months

Occupied months are selected and turned blued. Each of the selected months is further broken down into the typical week below.

Occupied Days of the Week

The Days of Week selection sets the typical week of occupied (blue) and unoccupied (white) days for each occupied month. The selected occupied days are further broken down with the occupied hours, and the unoccupied days are broken down into the unoccupied hours.

Occupied Hours

Each hour is broken down into 10% squares that can be selected to be occupied (blue) or left unselected (white). The Total Occupants (occupied) input is used for every blue square as a selected percentage of an hour. The Total Occupants (unoccupied) input is used for every white square. Based on the ratio of blue to white squares for each hour the number of people per hour is calculated. In this way, the user can easily select the percentage of time a building may be occupied while specifying the range of total occupants for the maximum and the minimum number of people inside the building. This can be an excellent energy saving strategy for both new and existing buildings.

Example Breakdown

Typical Educational Building

For this example, occupied hours will be simulated for January- May and September-December for the workweek of Monday-Friday. The months of June-August are set to 10% total occupancy.

The percentage of occupancy has been adjusted for each hour during the typical workday simulating when people arrive to work, work through the morning, go out for lunch, work through the afternoon, and leave toward the end of the day.

  • During the percentage of occupied times (blue squares) the lighting is 0.95 W/ft2 (LPD), appliance power is 0.75 W/ft2 (EPD), operating between 70° - 74° F, and a total occupant count of 80 people.

  • During the percentage of unoccupied times (white squares) the lighting is 0 W/ft2 (LPD), appliance power is 0.15 W/ft2 (EPD), operating between 59° - 84° F, and a total occupant count of 14 people.

Unoccupied hours will be simulated for the remaining time of the week for Saturday and Sunday during the same months of January-May and September-December. There is less activity during these days and therefore require a separate regular schedule as the function of the building will be different. The inputs work in the same way only simulating more time for unoccupied and set-back values.

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