The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 14, 1995
Filed:
Feb. 09, 1994
Ronald J Wenner, Brown Deer, WI (US);
George Rudich, Jr, Cedarburg, WI (US);
Johnson Service Company, Milwaukee, WI (US);
Abstract
A method and apparatus for controlling an environmental parameter is disclosed. The apparatus includes a source of energy controlled air and a source of external air. A damper determines the amount of external air and energy controlled air provided to the room. A control circuit controls the position of the damper in response to an enthalpy calculator. The enthalpy calculator includes a temperature sensitive resistor having a resistance RT and a relative humidity sensitive capacitor wherein the capacitance of the relative humidity sensitive capacitor is CS. An electronic circuit includes RT and CS and provides an output h: ##EQU1## The method includes the steps of providing energy controlled air and external air. The temperature and humidity of the external air are sensed, and the enthalpy is calculated using the equation ##EQU2## where t is the temperature and RH is the relative humidity. The amount of external air provided is adjusted using the calculated enthalpy as a parameter.