SolarTrac®

WindowManagement®: The Prerequisite to Daylighting

MechoShade’s AAC SolarTrac® System, is a proprietary software based control system designed to automatically adjust the position of the shades incrementally on the window to maximize view and daylighting while protecting people and work surfaces from direct sun, excessive brightness and glare.



SolarTrac’s intelligent multi-level command accounts for “Clear”, “Cloudy” or “Bright-Overcast” sky conditions in accordance with established criteria for vertical, horizontal or sloping windows. In addition, by integrating with BMS, HVAC and Lighting systems, AAC SolarTrac can help to reduce fossil fuels, electric and building maintenance costs. AAC SolarTrac factors in the sun’s angle of incidence, solar heat-gain (in BTUs or W/M2), allowable solar penetration, plus brightness and glare control.

AAC SolarTrac®

AAC SolarTrac® is able to react to local climatic variables such as sunny, cloudy or partially sunny/cloudy conditions.


The AAC SolarTrac ® adjusts shades incrementally on the window in accordance with the solar profile angle and BTU load relative to each zone or orientation.

The position of the shades is determined for each zone based on the window geometry, orientation, glazing optical properties, allowable solar penetration, and real-time sky conditions, ie sunny or cloudy. The goal is to limit solar penetration beyond a predetermined point, therefore reducing solar radiant heat gain and glare on work surfaces while allowing for the maximum amount of view and natural light into the space.

The AAC SolarTrac ® Window Management System is a multi-zone controller that:

  • On a predetermined hourly or daily schedule, AAC SolarTrac automatically positions the shade to meet varying sun angles.
  • Using 3 radiometers, it determines the momentary microclimatic conditions such as sunny, cloudy or bright-overcast sky conditions.
  • Maximizes the amount of natural light and view thru the window by keeping the shade as high up as possible while not allowing the sun to penetrate beyond a user defined point within the space (footprint — see art above)
  • Incorporates user defined internal time delays, for intermittent clouds and sun/no sun sky conditions and cycles the shades on a programmed basis.
  • During nighttime winter conditions it lowers the shades to provide additional insulation if desired.
  • During nighttime summer conditions it raises the shades to assist in nighttime cooling.
  • Includes manual override capability by zone for executive offices, conference rooms and training facilities.
  • MechoShade Systems, Inc. can monitor, perform system diagnostics and make adjustments via modem anywhere in the world.
  • Integrates with building-management systems. (Optional)

AAC SolarTrac® Window Management System benefits include:

  • Window shade alignment.
  • Uniform building appearance by elevation.
  • Optimizes use of natural light and views to the outside.
  • Provides HVAC engineers with the flexibility to downsize air conditioning or to operate at a higher temperature set point.
  • Improves productivity by: 1. Improving personal comfort. 2. Reducing the time employees spend adjusting shades. 3. Regulating brightness and glare on CRT screens to reduce eye strain and improve productivity.

AAC-Brightness Override Module


The Brightness Override Module is an optional system using internal light sensors. These sensors may be mounted to the ceiling or columns.

If the brightness on the glass exceeds specified levels, the AAC Brightness Override will lower the shades to the appropriate position to mitigate the excess brightness. This overrides the calculated position of AAC, which may otherwise have been a higher position. Shades can retract to the default positions preset by AAC from Brightness Override when the bright condition no longer exists.



Touch Screen Window Management
Color touch screens can be incorporated into the work space to allow intuitive access to multiple shade zones, providing ease of use to the user. A single touch screen can replace numerous switches and graphically inform the user which shades they can control. The touch screens run on a RS485 network and interfaces with the AAC SolarTrac, providing 2 way communication with SolarTrac so that the system knows at all times which shades are on manual override.

Shadow Override
For projects located in the center city or otherwise impacted by adjacent buildings, AAC's Shadow Override allows one to raise the shades in any zone that is in shadow. This strategy allows more daylight without direct sun and maximizes view to the outside for the occupants. Dimmable lighting systems can take advantage of the light and save enery and money by dimming the lights. This option requires a digitized 3D city scape map of the surrounding buildings to be analyzed by MechoShade, resulting in a database used by AAC to raise the shades.

Description of Operation
The multi-zone, multi-position, PC-based AAC SolarTrac® Window Management System was developed exclusively for the operation of ElectroShades®.

The system is an intelligent multi-level command program which automatically adjust the position of shades incrementally in accordance with the sun’s angle of incidence, solar heatgain factors in BTUs and allowable solar penetration. The system allows for brightness and glare control by adjusting the shades to “clear-sky”, “cloudy-sky” or “bright-overcast-sky” conditions. The AAC-SolarTrac system incorporates these elements in accordance with an established computer program for vertical, horizontal or sloping windows.

The AAC SolarTrac System is a multi-zone controller that:
  • Automatically positions the shades to meet varying sun angles.
  • Using solar meters, determines the momentary microclimatic conditions (clear, cloudy, or bright-overcast).
  • Incorporates user adjustable internal time delays, which adjust for intermittent clouds.
  • During nighttime winter conditions, lowers the shades to provide additional insulation.
  • During nighttime summer conditions, raises the shades.
  • Offers almost unlimited programming options to the end user such as lowering shades, at night to reduce heat loss and/or reduce internal illumination transmitted out of the building.
  • Includes manual override capability by zone.
  • Incorporates on-site-adjustments to operating standards, either by user or remotely via modem by MechoShade.

Master Specifications
A. Hardware

1. The AAC SolarTrac Window Management System shall be equipped with a standard desktop PC or compatible computer with all the necessary interfacing, hardware and software to accept the following:

a. Analog inputs for solar meters (solar-level detection).
b. Analog inputs for optional temperature sensors.
c. Digital inputs for building-computer priority commands.
d. Inputs for fire alarm and additional non-designated ports.

2. The AAC SolarTrac software is compatible with: ElectroShade motorized solar sun screens utilizing Motor Logic Controllers (MLCs), IQ/MLCs, Smart Submasters. using standard asynchronous motors.

ElectroShade motorized solar sun screens utilizing Intelligent Motor Control (IMC) System

B. Software
1. Each zone on each floor in each building (or building module) shall be independently addressable.

2. For raising and lowering shades, each zone shall have typically 3 default intermediate aligned stop positions (25, 50 and 75% down) plus full up and full down. As an option, additional programming can provide up to 16 incremental positions. Increment “0” represents the fully raised position. If five increments are selected for a particular zone of a floor of a building, the “0” setting indicates all the way up while “4” indicates fully down, with each increment one fourth of the total travel height.

3. Each zone on each floor in each building (or building module) shall have a set of tables which corresponds to a userdefined range of dates, times and shade positions. The user can access these tables via the key board and through menu-driven screens.

4. Each table shall have a user-definable set of solar-level conditions. These levels shall define “clear-day”, “overcast glare”, and “bright overcast sky” conditions. For the “clearday” mode, the shades shall follow the programmed positions. The other two modes represent special conditions when the shades move to a specified position.

5. Each zone shall have user-defined delays for cloud and sun conditions to prevent intermittent clouds or sun from triggering the above special modes.

6. Each zone shall have user-defined priority-command positions to accommodate alarm-signal indicators which are relayed from the building computer.

7. Designated zones may have user-defined time-of-day accessibility. The locally accessed Submaster and Local controls shall be returned to the automatic (AAC SolarTrac) master-computer unit at a user-defined time or period.

8. During normal operation, the status of all zones on each floor in each building shall be displayed. Solar-intensity levels shall be displayed and indoor and outdoor temperature readings can be displayed as an available option.

9. Operation of the shade motors throughout the system shall be staggered so that peak electrical-loading conditions are prevented. Remote access software shall also be provided to enable monitoring the performance of the system from a remote location via a dedicated analog telephone line provided by the end user.