HVAC Prediction for a Cost-Limited Home Thermostat

Case ID:

This technology addresses this problem by introducing a new cost-limited thermostat which provides real-time feedback on temperature-cost correlation and puts consumers in control of balancing their comfort and budget. When the temperature schedule or monthly budget is changed, the thermostat immediately displays how one affects the other allowing the user to always be in control of their thermostat and their budget.

Most homeowners would like to spend less on their air-conditioning and heating bills during the extreme heat of summer, and extreme cool of winter. Trivially, homes can spend $0 on heating and cooling by fully disabling their temperature control units; however, this may lead to discomfort. On the other hand, arbitrarily selected comfort levels may result in high costs to the homeowner which are not discovered until the previous month's electricity bill arrives. What is nontrivial is the ability to plan to spend a fixed amount (or an amount within an accepted tolerance) on the temperature of a building each month.


  • HVAC units in homes
  • HVAC units in businesses and commercial buildings



  • Proposed method accurately and immediately shows changes in cost as temperatures are changed
  • Runs on embedded hardware and does not need any external tools
  • Provides a link between setpoints and a bounded estimate of cost at those setpoints
  • Method uses setpoints based on cost, not temperature
  • Accurately predict and control thermostat maintenance costs

Status: issued U.S. patent #9,429,961

Patent Information:
Contact For More Information:
Tariq Ahmed
Sr Licensing Manager, College of Engineering
The University of Arizona
Lead Inventor(s):
Jonathan Sprinkle
Susan Lysecky
Xiao Qin