A piping system for recovery heat energy from an exhaust gas in a heat recovery furnace, the piping system comprising a piping inlet, where the piping inlet transects a wall of a stack zone of the heat recovery furnace, a piping run, the piping run fluidly connected to the piping inlet, and a piping outlet, the piping outlet fluidly connected to the piping run, where the piping outlet transects the wall of the stack zone of the heat recovery furnace, where the piping system is positioned in a stack zone of the heat recovery furnace between a stack inlet and a stack outlet.

A piping system for recovery heat energy from an exhaust gas in a heat recovery furnace, the piping system comprising a piping inlet, where the piping inlet transects a wall of a stack zone of the heat recovery furnace, a piping run, the piping run fluidly connected to the piping inlet, and a piping outlet, the piping outlet fluidly connected to the piping run, where the piping outlet transects the wall of the stack zone of the heat recovery furnace, where the piping system is positioned in a stack zone of the heat recovery furnace between a stack inlet and a stack outlet.

An exemplary insulator for a flue of a residential oven includes a bendable insulating body having a first end, a second end, and a bending portion. A first cut is disposed between the bending portion and the first end and a second cut is disposed between the bending portion and the second end. The first cut is expandable to form a first opening and the second cut is expandable to form a second opening.

An exemplary insulator for a flue of a residential oven includes a bendable insulating body having a first end, a second end, and a bending portion. A first cut is disposed between the bending portion and the first end and a second cut is disposed between the bending portion and the second end. The first cut is expandable to form a first opening and the second cut is expandable to form a second opening.

A closing member includes an annular portion and a flange portion. The annular portion is provided with a through hole and is in contact with an outer circumferential surface of an exhaust tube in at least a part of the through hole. The flange portion extends from an outer circumferential surface of the annular portion toward an outer side and is larger in outer diameter than an exhaust pipe. The flange portion contacts a tip end portion of the exhaust pipe on outside of a building so as to close a gap between the exhaust pipe and the exhaust tube. The flange portion is formed to protrude toward an outer side such that an entire circumference of the flange portion extends beyond an outer circumferential surface of the tip end portion of the exhaust pipe.

A closing member includes an annular portion and a flange portion. The annular portion is provided with a through hole and is in contact with an outer circumferential surface of an exhaust tube in at least a part of the through hole. The flange portion extends from an outer circumferential surface of the annular portion toward an outer side and is larger in outer diameter than an exhaust pipe. The flange portion contacts a tip end portion of the exhaust pipe on outside of a building so as to close a gap between the exhaust pipe and the exhaust tube. The flange portion is formed to protrude toward an outer side such that an entire circumference of the flange portion extends beyond an outer circumferential surface of the tip end portion of the exhaust pipe.

An exhaust tube holding member for holding an exhaust tube inside an exhaust pipe includes a main body. The exhaust tube is connected to a combustion apparatus and introduced into the exhaust pipe. The main body includes a first surface and a second surface opposing each other, and a rim surrounding the periphery of the first surface and the second surface. The main body is provided with an exhaust tube holding hole and an exhaust tube inserting notch. The exhaust tube holding hole is configured to penetrate the main body from the first surface to the second surface. The exhaust tube inserting notch is configured to penetrate the main body from the first surface to the second surface and extend from the exhaust tube holding hole to the rim.

An exhaust tube holding member for holding an exhaust tube inside an exhaust pipe includes a main body. The exhaust tube is connected to a combustion apparatus and introduced into the exhaust pipe. The main body includes a first surface and a second surface opposing each other, and a rim surrounding the periphery of the first surface and the second surface. The main body is provided with an exhaust tube holding hole and an exhaust tube inserting notch. The exhaust tube holding hole is configured to penetrate the main body from the first surface to the second surface. The exhaust tube inserting notch is configured to penetrate the main body from the first surface to the second surface and extend from the exhaust tube holding hole to the rim.

A heating coil for a plumbing vent is provided to melt snow and ice keeping the plumbing vent clear. The heating coil assembly comprises a hollow cylinder with a helicoid heating element, the cylinder configured to fit inside the plumbing vent. The assembly further comprises at least one bracket configured to fasten the cylinder and retain the helicoid heating element inside and above the cylinder. The heating coil is configured to melt snow and ice keeping the plumbing vent clear.

An exemplary insulator for a flue of a residential oven includes a bendable insulating body having a first end, a second end, and a bending portion. A first cut is disposed between the bending portion and the first end and a second cut is disposed between the bending portion and the second end. The first cut is expandable to form a first opening and the second cut is expandable to form a second opening.