GB579564A - Improved apparatus for the automatic regulation of the temperature in buildings - Google Patents

Abstract

579,564. Correspondence control systems. LANDIS & GYR. SOC. ANON. Jan. 26, 1943. No. 1302. Convention date, Jan. 30, 1942. [Class 40 (i)] [Also in Group XXXV] The heating system of a building is divided into two circuits I, II heating portions thereof respectively, and controlled by two external thermostats TR, TRb related in position to the respective portions. To minimize heat losses the control is arranged so that the thermostat calling for most heat controls, for example. through the action of a thermostat applied to the flow pipe of its related heating circuit, the supply of heat to both circuits while the remaining thermostat controls by similar means the heating fluid in its related heating circuit by regulating the mixture of flow and return fluid. The external thermostats TR, TRb shown are of the kind comprising a bimetal switch and heating resistance in an enclosure simulating the heat losses in the building, and have back contacts which produce electrical impulses, the duration of which in relation to the duration of the intervals increases with increased cooling of the thermostat. These impulses are transmitted to auxiliary heating windings on the related applied thermostats TA. TAb, thereby controlling their action in response to the temperature of the fluid. They are also transmitted through relay J, JI to a differential thermal relay TU which controls the action according to the invention by de-energizing a relay U when the thermostat TR calls for more heat and energizing it when the thermostat TRb makes the greatest demand. In the latter case, a contact U1 energizes the motor of a mixing valve Vb to open fully the flow pipe of circuit I and to close the admixture inlet thereof and a contact U2 energizes a relay UR to place under the control of applied thermostat TA, controlled by external thermostat TR, the motor of valve V, which controls the mixture in the flow pipe of circuit II. The contact U1 de-energizes a relay. UR1 whereby the motor of a valve Vb, regulating the supply of heat to a heat exchanger which supplies heat to both circuits I, II, is placed under the control of thermostat TAb controlled by external thermostat TRb. A corresponding change over occurs when the relay is deenergized by the thermostat TR calling for more heat. The system described includes a time switch S whereby reduced operation may be obtained at night. A contact on the time switch makes the night rate effective throughout the week-end. A switch NV renders the system inoperative and causes the heat supply valve Vp to be closed. Similar action occurs when the main switch H is opened. The invention is not limited to the type of heating system shown, nor to the kind of differential relay or thermostats employed or to motor actuation of the controls.