Appliance for improved venting

An adapter for varying the proportions of combustion products to dilution air in the vent gas of a fuel-burning appliance, said adapter comprising:

• A. a dilution air inlet:
• B. a combustion flue inlet:
• C. a mixing chamber;
• and
• D. at least one valve element defining at least first and second dilution air apertures and at least first and second combustion product apertures, said at least one valve element being movable between:
• i. a first position causing said first dilution air aperture to regulate the flow of dilution air through said dilution air inlet and causing said first combustion product aperture to regulate the flow of combustion products through said combustion flue inlet:
• and
• ii. a second position causing said second dilution air aperture to regulate the flow of dilution air through said dilution air inlet and causing said second combustion product aperture to regulate the flow of combustion products through said combustion flue inlet:
• wherein said first dilution air and first combustion product apertures are respectively adapted to provide a first ratio of dilution air to combustion products passing into said mixing chamber, and said second dilution air and second combustion product apertures are respectively sized to provide a second ratio of dilution air to combustion products passing into said mixing chamber, wherein said first and second ratios are different.

A flue assembly adapted for varying the proportions of combustion products to dilution air passing through it, said assembly comprising:

• A. a dilution air inlet:
• B. a combustion flue inlet;
• C. a vent:
• and
• D. at least one valve element defining at least first and second dilution air apertures and at least first and second combustion product apertures, said at least one valve element being movable between:
• i. a first position causing said first dilution air aperture to regulate the flow of dilution air through said dilution air inlet and causing said first combustion product aperture to regulate the flow of combustion products through said combustion flue inlet:
• and
• ii. a second position causing said second dilution air aperture to regulate the flow of dilution air through said dilution air inlet and causing said first combustion product aperture to regulate the flow of combustion products through said combustion flue inlet:
• wherein said first dilution air and first combustion product apertures are respectively adapted to provide a first ratio of dilution air to combustion products passing into said vent and said second dilution air and second combustion product apertures are respectively sized to provide a second ratio of dilution air to combustion products passing into said vent, wherein said first and second ratios are different.

A gas burning appliance disposed within a building adapted for controlling the proportion of combustion products to dilution air in its vent gas, said appliance comprising:

• A. a combustion chamber for burning gas and producing combustion products;
• B. a combustion flue inlet for passing flue gas from said combustion chamber to a mixing chamber;
• C. a dilution air inlet for passing dilution air into said mixing chamber;
• D. at least first and second flow restrictors, said first flow restrictor secured in a position regulating the flow of dilution air through said dilution air inlet and said second flow restrictor secured in a position regulating the flow of combustion products through said combustion flue inlet;
• wherein said first and second flow restrictors are defined by at least one valve element having first and second major faces and perforations extending through said first and second major faces, and wherein said first and second flow restrictors are respectively adapted to provide a ratio of dilution air to combustion products passing into said mixing chamber;
• and
• E. a low-temperature vent in fluid communication with said mixing chamber and providing a conduit for combustion products out of the building.