One aspect of this disclosure provides a heat exchanger that comprises a first panel half coupled to a corresponding second panel half that form a passageway having at least a first chamber adjacent an inlet end of the passageway and a second chamber and overlapping interference patterns formed in each of the first and second panel halves that extend along at least a portion of the length of the passageway and located between at least the first and second chambers.

A control valve includes a valve housing, a joint member, a valve body, and a sealing tube member. The sealing tube member has a biasing pressure receiving surface that receives a pressure of a liquid inside the valve housing and biases the sealing tube member to the valve body side. An area S1 of the biasing pressure receiving surface and an area S2 of a valve sliding contact surface of the sealing tube member are set to satisfy Expressions (1) and (2),
S1<S2≤S1/k   (1)
α≤k<1   (2) where k is a pressure reduction constant of a liquid flowing through a minute gap between the valve sliding contact surface and the valve body, and α is a lower limit value for the pressure reduction constant determined based on physical properties of a liquid.

One aspect of the disclosure provides a termination for use with a furnace. The termination, in one embodiment, includes a face plate including an exhaust region and an air supply region, the face plate having a front surface and an opposing back surface. The termination, in this embodiment, further includes an exhaust termination portion extending from the back surface in the exhaust region, the exhaust termination portion capable of engaging a terminal end of a variety of different size exhaust conduits associated with a furnace. The termination, in this embodiment, further includes an opening extending through the face plate in the exhaust region, the opening aligned with the exhaust termination portion.

A control valve includes a valve housing, a joint member, a valve body, and a sealing tube member. The sealing tube member has a biasing pressure receiving surface that receives a pressure of a liquid inside the valve housing and biases the sealing tube member to the valve body side. An area S1 of the biasing pressure receiving surface and an area S2 of a valve sliding contact surface of the sealing tube member are set to satisfy Expressions (1) and (2),

S1<S2S1/k (1)

k<1 (2) where k is a pressure reduction constant of a liquid flowing through a minute gap between the valve sliding contact surface and the valve body, and is a lower limit value for the pressure reduction constant determined based on physical properties of a liquid.

One aspect of this disclosure provides a heat exchanger that comprises a first panel half coupled to a corresponding second panel half that form a passageway having at least a first chamber adjacent an inlet end of the passageway and a second chamber and overlapping interference patterns formed in each of the first and second panel halves that extend along at least a portion of the length of the passageway and located between at least the first and second chambers.

An alternative-fuel gas orifice, a gas furnace configured to employ the same and a method of designing a gas orifice. In one embodiment, the gas orifice includes: (1) a body having an aperture extending therethrough and including: (1a) a metering neck having a cross-sectional area such that a given flow rate of a gas is established when the gas is delivered to the gas orifice at a given alternative-fuel delivery pressure and (1b) a diffuser having a cross-sectional area larger than the cross-sectional area of the metering neck and a length such that the gas achieves a substantially laminar flow before exiting the diffuser.

A condensation trap comprising an inlet chamber, a vent chamber and an outlet chamber. The inlet chamber is configured to receive condensate fluid through an external opening therein. The vent chamber is in fluid communication with the inlet chamber via a first passageway that includes an internal opening of the inlet chamber. The internal opening is located substantially at an opposite end of the vent chamber as the external opening. The outlet chamber is in fluid communication with the vent chamber via a second passageway that includes an internal opening in a sidewall of the vent chamber and an interior opening in an end of the outlet chamber. The outlet chamber is configured to transmit the condensate fluid through an exterior opening located at an opposite end of the outlet chamber. A vent volume portion is greater than a total volume of an internal space of the inlet chamber.

A furnace heat exchanger assembly includes first and second heat exchanger halves. The first heat exchanger half includes a first half of an exhaust channel and an inner joint flange half at an end thereof. The second heat exchanger half includes a second half of the exhaust channel and an outer joint flange half at an end thereof having first and second capturing tabs. The first and second heat exchanger halves are coupled together such that the first and second capturing tabs substantially overlap the inner joint flange half to form a joint flange.

A condensation management system, a furnace having the condensation management system and a cold end header box employable in the condensation management system are disclosed herein. In one embodiment, the condensation management system includes: (1) a first drain hose positioned to drain flue condensation from a flue pipe of the furnace, (2) a second drain hose positioned to drain the flue condensation from the flue pipe and (3) a condensation collector box configured to collect both the flue condensation and combustion condensation from a heat exchanger of the furnace, the condensation collector box including at least one drain for draining both the flue condensation and the combustion condensation therefrom.

A header box, a furnace and a blocked condensation protection system are disclosed herein. In one embodiment, the header box includes: (1) a first channel having a first channel supply port positioned to be in fluid communication with an inlet of a combustion air blower and a first pressure port couplable to a first input of a pressure sensing device, the combustion air blower and the pressure sensing device associated with the cold end header box and (2) a second channel having a second channel supply port positioned to be in fluid communication with the inlet of the combustion air blower, a second pressure port couplable to a second input of the pressure sensing device and a pressure reference inlet, the second channel in fluid communication with the first channel and configured to have about a same pressure as the first channel when the pressure reference inlet is blocked.