5.2.1 Treatment Zone Control Definition Table

The Treatment Zone Control table is used to define the control settings for each treatment zone. This table consists of the following components:

Treatment Zone – There is one row in the table for each treatment zone defined on the geometry input page. The first column indicates which treatment zone each row represents. The radio buttons next to the treatment zone column are used to select a given treatment zone for the automatic generation buttons described in the next section.

Shade Control Type – This column sets the control type for each treatment zone. Three control types can be selected: fixed, manual or auto. The fixed and manual control settings can be used to simulate a whole range of user types from a completely passive user that keep their shades down and fixed all the time to extremely active users that adjust their blinds regularly.

The fixed control simply keeps the blinds or shades shut for all the calculations. This control type can be used to simulate manual control for a ‘passive’ occupant.

The manual control treats each window individually and according to the manual shade exitance threshold and time delay settings on the Advanced Options page. When SPOT performs its simulations, it will look at the light leaving each window (exitance) and if it has exceeded the limit it will shut the window treatment until the final glare occurance and set time delay have passed.

The auto control type simulates the treatment zone being controlled by a defined photosensor position, type, and setting. The rest of the fields in the definition table relate to the sensor settings and do not apply with ‘fixed’ shade control. Automatic shade control also assumes an ‘open-loop’ sensor placement where the photosensor signal does not change depending on whether shades are drawn or retracted.

Shade Control Sensor Vectors – The three adjacent position fields define the location, aiming and rotation of the sensor for the current treatment zone using vector notation. The X values for each vector (1st number) represent the E-W dimension of the space. The Y values (2nd number) represent the N-S dimension of the space. The Z values represent the height component. The vectors must be entered with a comma separating the X, Y, Z values. The vectors do not have to be unitized.

Shade Control Sensor Location – The location vector gives mounting coordinates. The user will have to ensure the sensor does not get placed within a wall, overhang, or lightshelf element as this will result in inaccurate results. The button, discussed above, will automatically input the sensor location field for the selected Treatment Zones.

Shade Control Sensor Aiming – The aiming of the sensor gives the direction in which the photocell is looking. The button, discussed above, will automatically input the sensor aiming field for the selected Treatment Zones.

Shade Control Sensor Rotation – The rotation of the sensor indicates the direction in which the prominent sensor housing feature will face. The default is up for sensors on a wall and local building north for sensors on the roof. The button, discussed above, will automatically input the sensor rotation fields for the selected Treatment Zones.

Sensor Type – This field designates the type of photosensor to use. The current database of photosensor types includes five generic sensor spatial sensitivity distributions: a cosine distribution, 45o cone cosine, 55o cone cosine, 65o cone cosine, and an old Watt Stopper coned distribution, TWS-1. In addition, the specific photocell products tested in the 2007 NLPIP Specifier Report on Photosensors (see Appendix E for reference) are included in the SPOT database. Refer to Section 5.3 for more information on the sensors available.

Shade Sensor Setpoint – These fields define the sensor set-point in terms of ‘signal’ and in terms of illuminance at the sensor. The ‘signal’ setting relates to the response generated by the given sensor distribution file, which is only equal to illuminance for a cosine distribution sensor. The illuminance field indicates the illuminance on the sensor that would produce the given signal under a standard CIE overcast sky distribution. Both these fields will be automatically filled out if the button is selected. After this button has been selected, the corresponding illuminance field will automatically be updated. The signal is all that matters for SPOT, but the corresponding illuminance field can give useful information for commissioning purposes.