VAV boxes provide cooling in harmony with perimeter heating, with both systems controlled by a single thermostat. When the perimeter heating valve no longer seats properly, unwanted heat is continuously introduced into the space. The thermostat automatically compensates by increasing cooling to maintain the desired room temperature. Occupants remain comfortable, but the simultaneous heating and cooling conceal significant energy waste, allowing the problem to persist unnoticed.
Letter of support
David Strain’s invention demonstrated an efficiency advantage greater than 15°/o favoring the diamondshaped
actuator over a conventional actuator.