Furnace condensate trap

A condensate drain trap comprising:

• a housing having first, second and third chambers;
• the housing including a first aperture having a first size and providing ingress for a first fluid into the first chamber and providing egress for a second fluid from the first chamber;
• the housing including a second aperture having a second size less than the first size and providing ingress for the first fluid into the second chamber and providing egress for the second fluid from the second chamber;
• the housing including a third aperture providing ingress for the second fluid into the third chamber and providing egress for the first fluid from the third chamber;
• and
• the first chamber including restrictors to retard passage of the second fluid without substantially retarding the passage of the first fluid.

A condensate drain trap assembly comprising:

• a housing having an interior divided into a first inlet chamber, a second inlet chamber, and an outlet chamber;
• the housing including a first aperture forming a first inlet to the first inlet chamber;
• the housing including a second aperture forming a second inlet to the second inlet chamber;
• the housing including a third aperture forming an outlet from the outlet chamber;
• the size of the first inlet being greater than the size of the second inlet;
• and
• the first inlet chamber including a plurality of restrictors adapted to enhance liquid flow while restricting airflow.

A method of controlling condensate and airflow in a furnace comprising the steps of:

• allowing impeded airflow through a condensate trap to a cold header box and to an inducer fan at startup;
• providing unrestricted condensate drainage to the condensate trap from the inducer fan;
• providing restricted condensate drainage to the condensate trap from the cold header box;
• accumulating condensate in the condensate trap;
• and
• blocking the flow of air through the condensate trap when the accumulated condensate reaches a first predetermined height.

A gas furnace comprising:

• a condensate trap assembly having first, second and third apertures;
• a cold header box having an aperture adapted to drain condensate;
• an inducer fan having an aperture adapted to drain condensate;
• a housing about the condensate trap assembly, the cold header box and the inducer fan, the housing including an outlet;
• a first condensate and ambient air line operatively connected between the cold box aperture and the first trap assembly aperture;
• a second condensate and ambient air line operatively connected between the inducer fan aperture and the second trap assembly aperture;
• and
• a third condensate and ambient air line between the housing outlet and the third aperture;
• the condensate trap assembly including air pressure enhancement devices between the first aperture and the third aperture.