Apparatus and method for energy saving control of heating, ventilating and airconditioning (HVAC) systems.

摘要

Electronic processing means (17) in combination with dedicated sensing apparatus (16) is used to control the operation of an HVAC system which regulates the temperature in one or more temperature controlled spaces (98,99,100) through modulation of the discharge temperature from one, or all, of a combination of air conditioning sources including, a source of mixed air comprised of some proportionate mixture of outside air and return air from the controlled spaces (98,99,100), a source of hot air, and a source of cold air. The sensing apparatus (16) provides output signals representative of each of a plurality of selected sensed parameters within the HVAC system including source discharge temperatures, space temperatures, and outside air temperatures, in addition to relative humidity of outside air and return air from the spaces. The electronic processing means (17) successively samples and registers successively sampled values of the sensed parameters from the sensing apparatus; and provides in response thereto, calculated reference temperatures in dependence on the summation of the product terms of a space temperature error multiplied by a proportional gain constant and an integral gain constant, the electronic processing means (17) controlling the modulation of the sources of mixed air, hot air, and cold air in dependence on the temperature difference between the calculated reference temperature value and the corresponding sensed source discharge temperature. The electronic processing means (17) and associated sensing apparatus (16) being readily adapted for interface with existing HVAC systems, the electronic processing means (17) control functions being implemented through interface apparatus (20) installed in each of the existing HVAC control lines associated with the sources of mixed air, hot air, and cold air and selectably operable in either of two positions to provide control of the HVAC system by the electronic processing means (17) when operated in a first position, and to allow control of the HVAC through existing control lines when operated in a second position.