System for air temperature maintenance with air cleaning feature

Abstract

In a system for cleaning, and for maintaining a desired temperature in, the air within the interior of a building, an activated carbon filter is disposed in a filter housing forming part of a conduit connected from a supply duct to a return duct. Air flows through the activated carbon filter as a result of the difference between the pressures of the air in the respective ducts, and substantially the entire quantity of air within the building is passed through the carbon filter in a short time.

What is claimed is: 
     
         1 . A system for cleaning, and for maintaining a desired temperature in, the air within the interior of a building, the system comprising an HVAC unit having a supply and a return duct, and a by-pass conduit connected from the supply duct to the return duct for carrying a fraction of the air delivered by the HVAC unit directly through the supply duct to the return duct, said by-pass conduit having a carbon filter disposed therein for removal of contaminants from said air fraction. 
     
     
         2 . A system for cleaning, and for maintaining a desired temperature in, the air within the interior of a building, the system comprising:
 a first air flow path;   a heat exchanger forming a part of said first air flow path;   apparatus connected to the heat exchanger for modifying the temperature of the air in said first air flow path;   a supply duct forming a part of said first air flow path and arranged to deliver air from the heat exchanger to the interior of said building;   a return duct forming a part of said first air flow path and arranged to deliver air from the interior of said building to the heat exchanger;   a blower arranged to cause air to flow from said return duct, and, through said heat exchanger, to said supply duct;   a conduit, connected from said supply duct to said return duct, said conduit providing a second air flow path that by-passes said first air flow path; and   an activated carbon filter in said conduit, said activated carbon filter being arranged to filter air flowing through said second air flow path from the supply duct to the return duct;   whereby, as a result of a difference between the pressure of air in said supply duct and the pressure of air in said return duct resulting from operation of said blower, a fraction of the air in the interior of said building passes through the activated carbon filter when the blower is operating.   
     
     
         3 . The system according to  claim 2 , including at least one fiber filter disposed in said first air flow path upstream of the heat exchanger. 
     
     
         4 . The system according to  claim 2 , in which said activated carbon filter is removable from said conduit for replacement. 
     
     
         5 . The system according to  claim 2 , in which said conduit comprises a filter-containing unit for containing said activated carbon filter, a first conduit part connecting said filter-containing unit to said supply duct on one side of said activated carbon filter, and a second conduit part connecting said filter-containing unit to said return duct on an opposite side of said activated carbon filter, said activated carbon filter having an air flow cross-sectional area, larger than the air flow cross-sectional areas of either of said first and second conduit parts, and said filter-containing unit having a central filter-containing part, a first tapered transition on one side of said central filter-containing part for connection to said first conduit part and a second tapered transition on an opposite side of said filter-containing part for connection to said second conduit part. 
     
     
         6 . The system according to  claim 5 , in which said activated carbon filter is removable from said central filter-containing part for replacement.