Inexpensive Software Automatically Controls Multiple Existing HVAC Systems in a Building to Minimize Energy Use Without Sacrificing Comfort

Technology #34072

Integrated HVAC Control for Multiple Space Conditioning Systems©: Smart thermostat software for optimizing the use of a building’s different heating and air conditioning systems.

Researchers at the University of Central Florida have developed a software system that provides automatic, centralized control of different space conditioning systems in a home or office buildings. For example, the UCF Integrated HVAC Control for Multiple Space Conditioning Systems© can be used to coordinate operations among a building’s central heating/air conditioning units and mini-split heat pumps (MSHPs), eliminating the need for frequent adjustments to temperature and humidity distribution. More importantly, the low-cost smart thermostat software can help to minimize the amount of energy used to heat and cool a building while meeting the set comfort levels of different rooms.

Technical Details

The UCF invention is a software system that integrates and automatically controls the following:

  • Temperature set point(s) of multiple space conditioning systems, including MSHPs
  • Fan cycling characteristics of central heating and cooling systems. The characteristics include the desired room temperature (set point) that an occupant enters into the central system and the outdoor temperature.

The software system can be retrofitted with any existing space conditioning system to minimize overall energy use and to maximize occupant comfort throughout the rooms of a home or building.

In one example application, the automaticcontrol system is in a home with an existing ductless MSHP and a ducted central heating/cooling system. The software links to thermostats to control the space conditioning systems via an open-source application programming interface. It also links to open source weather data available from the U.S. National Weather Service.

When installed, the new system focuses on using the higher efficiency MSHP as much as possible to condition the entire home. The system uses the lower efficiency central system only when comfort targets are not achievable with the MSHP. The control scheme works to automatically adjust the set point temperature of the MSHP to be lower than the central system during cooling and higher than the central system during heating. To maximize comfort in rooms without an MSHP, the UCF system periodically invokes the central system fan to mix air among the rooms.


  • Low-cost upgrade to existing systems
  • Automates optimization adjustments for temperature and humidity across integrated systems


  • Smart thermostats

Copyright and Trademark Information

Integrated HVAC Control for Multiple Space Conditioning Systems©, Copyright registration: TXu 2-146-159

Issue Date: 04/29/2019