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Attic ventilation control system

  • US 4,251,026 A
  • Filed: 12/05/1979
  • Issued: 02/17/1981
  • Est. Priority Date: 12/05/1979
  • Status: Expired due to Term
First Claim
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1. A control system for controlling an electrically powered exhaust fan over a broad range of summer and winter temperature conditions, said control system coupling the exhaust fan with an electrical power source, said control system comprising:

  • a first thermostatic control means for electrically coupling said electrical power source to said exhaust fan without periodic interruption when the temperature exceeds a first predetermined temperature;

    a second thermostatic control means for periodically electrically coupling said electrical power source to said exhaust fan only when the temperature falls below a second predetermined temperature, said second thermostatic control means comprising a thermostat, an electrically-powered percentage timing means for repetitively timing a preselected time interval in a predetermined time period, said thermostat coupled with said percentage timing means to provide electrical power from said electrical power source to said percentage timing means only when the temperature falls below said second predetermined temperature, and means for coupling said percentage timing means to said exhaust fan to electrically couple said exhaust fan to said electrical power source during said preselected time interval.

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