About

The HVAC Smart Control is a feedback and control system that makes economically efficient control decisions for heating and cooling of buildings. It does so by processing temperature and humidity data from indoor and outdoor sensing units, in addition to CO2 readings indoors, to intelligently and economically maintain desired comfort and air quality within buildings the system is implemented. The system contains three units: an outdoor sensing unit, a main control sensing unit, and the display unit. It is also designed such that additional units and features can be added easily in the future. The outdoor sensing unit takes outside temperature and humidity readings and transmits that data either wirelessly over 802.15 RF or - should interference prove to be problematic - wired over RJ-45 cable to the main control unit.

The main control unit receives both inside temperature, humidity and CO2 readings, as well as the outside temperature and humidity readings, and sends that data to the display unit. The low power display unit gathers the parameter data and determines the most economical way to run the HVAC system. In addition to the readings, the main control unit takes into account the types of HVAC equipment installed, such as a dehumidifier or an additional AC unit, customizing the efficiency computation for the particular hardware installed at the premises. It then sends control signals back to the main control unit that then turns on and off relays that control HVAC system components. Furthermore the display unit acts as a gateway to the internet for secure remote access should the user realize the air conditioning was left set at a less economical setting with no occupants, or if they simply wish to view the current readings in the building. The display unit also features a seven inch touch screen to make interactions and programming easier and more intuitive, eliminating a common reason why many households do not use the programming features of their thermostat.

Motivation

Heating and cooling costs are a major contribution to energy use in the United States. We found this project appealing as we knew we could contribute positively to solving this problem. According to the Energystar.gov, by simply programming your thermostat you can save $180 on average on your energy bills. However due to how complicated many thermostats are to program to the average user, even this basic feature isn't used.

Our project does the basics right and then expands on it. By creating an easy to use scheduling software user interface, and a relatively large 7" touch LCD which makes programming our device easy. It further expands on this by introducing the ability to add additional energy saving features, such as the ventalation of fresh air should the outside air be colder the system will automatically cool the house to desired temperature cutting energy consumption even further, or a dehumidifier as humidity can add to perception that a house is hotter than it is.