Abstract: A curtain control system for controlling curtains of an animal enclosure having an electrically-operated forced air ventilation system and a plurality of adjustable drop curtains. Each of the drop curtains has an associated curtain control device for providing supplemental ventilation during power failure or excess temperatures in the enclosure. Each of the curtain control devices includes a winch for winding and unwinding a curtain control cord extending between the curtain and the winch. A winch release is moveable between a hold position for normally holding the winch handle stationary to prevent unwinding of the curtain control cord and a release position to release the winch handle and thereby release the curtains to a dropped, open position. Electromagnets hold the winch releases in the hold position during application of current and permit movement of the winch release to the release position upon interruption of electric current to the electromagnets.

Abstract: A method of ventilating an animal enclosure such as a poultry house which permits alternating use of powered sidewall ventilation, natural sidewall ventilating and powered tunnel ventilation dependant upon outside temperature, with automatic control of the ventilation devices to insure safe and effective use.At and below a predetermined low outside ambient temperature, sidewall ventilation exhaust fans are operated to exhaust air drawn into the animal enclosure through the sidewall ventilation openings while tunnel ventilation openings are closed and tunnel ventilation fans are disabled to achieve a relatively low level of powered air movement through the animal enclosure.Between a predetermined middle range of outside ambient temperature, the sidewall ventilation openings are opened while disabling both sidewall ventilation exhaust fans and tunnel ventilation exhaust fans to achieve natural cross-ventilation through the animal enclosure.

Abstract: An energy management apparatus is disclosed for providing temperature responsive ventilation in an animal enclosure (A). An outside temperature sensor 15 cooperates with a cycle timer 21 to operate an output device such as a ventilation fan (10) for a variable percentage of time during consecutive given time intervals. A controller (12) cooperates with the temperature sensor (15) and the cycle timer (21) to automatically vary the percentage of fan (10) operation time during each given time interval in response to temperature changes in the outside air whereby constant minimum ventilation efficiency is maintained within enclosure (A). An indoor temperature sensor (16) can be optionally provided to override the outdoor sensor (15) to ensure that the temperature within the enclosure (A) remains within desired limits.

Abstract: An apparatus responsive to electric power failure for opening curtains or doors normally covering ventilation openings in a confinement house of the type used for raising poultry and livestock is disclosed. An electromagnet (59) is provided which is energized by the electric power supply (41) to the house (10) and is de-energized upon failure of the electric power supply (41). A pivoted metal strip (61) is normally in contact with the magnet (59) and is interconnected by means of a cord (66) with the winch (25) which is used to raise and lower the curtains (16). When the electric power (41) fails and the electromagnet (59) is de-energized, the cord (66) releases, and allows the curtains (16) to fall under their own weight. A capacitor (78) prevents de-energization of the magnet (59) when momentary power failures occur.