GB1103525A - Heating and ventilating systems - Google Patents

Abstract

1,103,525. Automatic temperature control. ROWBERRY & CO. Ltd. Dec. 19, 1966 [March 11, 1966], No.10906/66. Heading G3R. A temperature control system for an enclosure includes both heating and ventilating means responsive to the temperature of the enclosure, means being provided to ensure that the ventilating means are constrained to a low output whilst the heating means is operative. The ventilating means comprises a plurality of fans the speeds of which are controlled by devices C2, C3, C(HIGH) are temperature sensitive devices TH2, TH3 and TH(HIGH), the fans running at a minimum speed when no device C is energized. Heating means H which may be an electric or non-electric heater, is energized under the control of a temperature sensitive device HR, all the devices HR, TH2, TH3, TH(HIGH) being responsive to the temperature of the enclosure. With a switch SW1 in the AUTO position and the heater H de-energized a relay R1 is also de-energized thus contacts R1-a are closed. Relay R2 is energized closing contacts R2-a, R2-b and the ventilating fans operate at speeds determined by the condition of the devices TH. However, energization of the heater H with consequent energizations of relay R1 causes contacts R1-a to open whereupon the devices TH are rendered inoperative and the ventilating fans run at low speed. Should it be desired that the fans run at a second speed whilst the heater H is energized a switch SW2 is provided having a contact 2 whereby such a speed can be selected. The switch SW1 is provided with contacts LOW, 2, 3, HIGH whereby constant fan speeds may be selected irrespective of the operation of the heater H.