A flooring underlayment includes a base membrane and a cover membrane. The base membrane is configured to be installed between a subfloor and floor tiles to allow movement of the floor tiles relative to the subfloor. The cover membrane is configured to be coupled to the base membrane to form a flat surface for supporting the floor tiles. The cover membrane is configured to be coupled to the base membrane using at least one of a snug fit and a snap fit.

Provided are a heat exchanger capable of cooling a shell plate and having good assemblability and a hot water apparatus having the same. A primary heat exchanger includes a heat exchanging portion, a shell plate, and a shell pipe portion. The shell plate surrounds the heat exchanging portion. The shell pipe portion is for cooling the shell plate. The shell plate includes a front surface portion and a main body portion. The main body portion is installed on the front surface portion and is formed by bending one sheet of plate into a U shape. The shell pipe portion is bent in a U shape along an inner surface of the main body portion and installed on the inner surface.

An improved heat exchange apparatus is provided with an indirect evaporative heat exchange section consisting of a series of serpentine tubes which are kept uniformly spaced in the return bend section. Providing uniform return bend spacing on the return bend ends allow for ease of circuit assembly (stacking), ease of coil pull-down, ease of manufacturing, reduction in production cost, produces a higher quality hot dip galvanizing process and is a more robust design that tolerates manufacturing variability issues such as variable tube circuit length and variable return bend angles. Uniform return bend spacing also reduces scaling relative to prior art designs which had wet/dry areas resulting from shadowed tubes which were non-uniformly spaced, provides for better inspection and access to the tubes in the return bend area, maintains uniform air passage around tubes, promotes better tube wetting of the return bend area and ultimately promotes higher quality and higher performing heat exchanger coils.

Provided is a heat exchanger which includes a plurality of meandering heat transfer pipes that includes first and second heat transfer pipes, as the plurality of heat transfer pipes, which are adjacent to each other in a predetermined y direction and are misaligned with each other in a z direction such that a plurality of straight pipe parts are in a non-overlapping state in the y direction, in which a first recessed part recessed in the y direction is provided in each curved pipe part of the first heat transfer pipe, and a part of each curved pipe part of the second heat transfer pipe is fitted into the first recessed part.

An indirect heat exchanger has two airflow paths and an airflow generator to draw air through the airflow paths. A fluid conduit passes through the heat exchanger such that a cooling region is positioned within each of the flow paths. A dispenser is positioned to dispense evaporative liquid on one of the cooling regions. The dispenser operates in a wet mode and a dry mode. A controller regulates airflow through the first flow path and the second flow path, and also controls the operation of the dispenser. In this way, the controller may operate the airflow paths independently such that the airflow through a flow path operating in the dry mode is greater than that of the flow path operating in the wet mode.

An improved heat exchange apparatus is provided with an indirect evaporative heat exchange section consisting of a series of serpentine tubes which are kept uniformly spaced in the return bend section. Providing uniform return bend spacing on the return bend ends allow for ease of circuit assembly (stacking), ease of coil pull-down, ease of manufacturing, reduction in production cost, produces a higher quality hot dip galvanizing process and is a more robust design that tolerates manufacturing variability issues such as variable tube circuit length and variable return bend angles. Uniform return bend spacing also reduces scaling relative to prior art designs which had wet/dry areas resulting from shadowed tubes which were non-uniformly spaced, provides for better inspection and access to the tubes in the return bend area, maintains uniform air passage around tubes, promotes better tube wetting of the return bend area and ultimately promotes higher quality and higher performing heat exchanger coils.

A pipe heat exchanger for a baking oven has a plurality of heat exchanger pipe sections configured to guide a heat carrier fluid, the heat exchanger pipe sections being arranged adjacent to each other in an arrangement plane. A distance between adjacent pipe sections is smaller than a pipe diameter and greater than 1% of the pipe diameter. The result is a pipe heat exchanger, which allows a baking space to be heated efficiently and variably.

The present invention provides an economizer 70 including a plurality of cylindrical heat transfer tubes 71a-71d extending along a crossing direction crossing a flowing direction of combustion gas and disposed at a predetermined disposition interval P along the flowing direction, the combustion gas and fluid flowing in the plurality of heat transfer tubes performing heat exchange, and a swirl preventing section 75 disposed in contact with a downstream side outer circumferential surface 71Aa-71Ad in the flowing direction of each of the plurality of heat transfer tubes 71a-71d and configured to prevent a swirl of the combustion gas from occurring near the downstream side outer circumferential surface 71Aa-71Ad.

A membrane system includes a base membrane and a cover membrane. The base membrane is configured to be installed between a subfloor and floor tiles to allow movement of the floor tiles relative to the subfloor. The base membrane includes a base layer and studs projecting from the base layer. The studs are configured to hold a heating cable in place when the heating cable is positioned between adjacent ones of the studs. The studs have free ends that define pockets therein. The cover membrane is configured to be coupled to the base membrane to encapsulate the heating cable between the base membrane and the cover membrane. The cover membrane includes a cover layer and studs projecting from the cover layer. The studs on the cover membrane are configured to fit within the pockets in the base membrane to couple the cover membrane to the base membrane.

A liquid to refrigerant heat exchanger includes a coolant volume that is at least partially defined by a plastic housing and by a metal closure plate. The plastic housing is sealingly joined to the closure plate along an outer periphery of the closure plate. The metal closure plate can be part of a brazed assembly that defines a continuous refrigerant flow path through the heat exchanger between a refrigerant inlet port and a refrigerant outlet port.