Specifications

95
Efficient HVAC Control and Feedback System
Main Control Unit
User Interface Remote Sensing Unit
 Bidirectional Communication with LCD Touch Screen User Interface
 Receives wireless information from remote sensing unit
 Outputs 24V AC “Control Voltage” to multiple Appliances
 Connects to existing wireless internet network
 Connects to web server to allow user to view conditions and view / change
settings from a mobile device
 Bidirectional communication with
Main Control Unit
 Touch screen interfacing allows
user to manipulate interface with
his/her finger
 7 inch display allows for visually
appealing and easy to use
display
 Precision measurements of
temperature and relative humidity
 Wireless communication with main
control unit to report data
 Weatherproof housing
 Battery powered for ease of
installation
Figure 47 - High - Level System Block Diagram
The LCD touch screen is the main user interface of our system which primarily
consists of a 7” display that is visually appealing to the user, allows for
bidirectional communication with the Main Control Unit and as well as let the user
to manipulate the touch screen interface by means of his/her finger. The web
server will allow for remote manipulation of the system settings using any web -
enabled mobile device.
The Remote Sensing Unit is the least complex of the four main components.
The components housed inside the Remote Sensing Unit are, a temperature and
relative humidity sensor, a microcontroller, and a ZigBee wireless chip. The
sensor takes both temperature and relative humidity readings and reports these
values to the microcontroller also located in the remote sensing unit. The
microcontroller intakes the readings and if necessary; manipulates the data so
that it can be sent to the ZigBee chip in a form that is acceptable for wireless