GB685396A - Improvements in means for heating and ventilating buildings - Google Patents

Abstract

685,396. Unit apparatus. VANE, M. Oct. 8, 1951 [Oct. 10, 1950; Feb. 28, 1951], Nos. 24675/50 and 4883/51. Class 137 A heating and ventilating unit for buildings, e.g. greenhouses &c. comprises a twopart casing, or duct, mounted on a board 10 sealed in a wall or roof opening, one part 24 of the casing protruding on the outside of the building having a louvred fresh air inlet and the other part 23, on the inside of the building and having a fan 14 and heating element 13, being spaced from the outer part 24 by bolts 12 and distance pieces 25 to form a flanged annular inlet 20 for recirculated air. The louvred fresh air inlet communicates with a second annular opening 26 between the rim of a fixed circular plate 27 and the inside surface of the casing 24. A solenoid 28, fixed to a plate 33 carried by the fan motor 16, when energized, moves a valve plate 38 secured to an axially moving armature 45, to close the opening 20 and open the fresh air opening 26, the reverse sequence of operation occurring when the solenoid is de-energized and the plate 38 is urged by a spring 44 in the opposite direction. The motor 16 is suspended on a metal spider 17 suspended from the casing 23, and the fan directs air over well spaced heating elements 13. The switches of the solenoid 28, the motor 16, and the heating elements 13, are controlled by heat responsive means e.g. bi-metal strips, so that the temperature within the building can be maintained within the desired range. While the building temperature remains within this range the unit is inactive; when the range is exceeded the solenoid 28 and the motor 16 are energized and cool fresh air is delivered to the room; and when the temperature falls below the range it is raised by the switching on of the motor and the heater so that warm air is recirculated. The heat elements may be protected by thermal relays which switch off the heat elements should a fault develop in the fan motor. A delay switch may be incorporated to maintain the fan rotating for a time at the end of a heating cycle to extract residual heat from the elements 13. In a modification, Fig. 4, the casing comprises a single duct of square section, the fresh air, and recirculated air openings 49, 48 being opened and closed by.pivoted vanes 51, 50 respectively in anti-phase by a solenoid 55 and links 52, 53, 54, 56. Either of the two types of units may be used in conjunction with ventilator openings situated in other parts of the building, the ventilators being operated by a shaft linked to the main, or to an auxiliary solenoid.