As far as stages go, the big game is one of the biggest out there, and there’s a small army responsible for making sure the game goes off without a hitch. Behind that army of personnel is an even larger assemblage of vehicles, equipment, and other technology that help along the way – one of which is the heat exchanger.

There are a number of industrial processes that require extremely cold temperatures – sometimes as cold as -150°F. For the equipment used in such applications, those low temperatures pose some unique challenges. In this post, we’ll detail some of the temperatures involved and outline some things to consider with regard to heat exchanger design and materials for low-temp applications. 

Cooling data center IT equipment using air has been the industry standard for as long as there's been a data center industry. However, advances in computing technology have pushed the limits of what air-cooled systems are able to efficiently keep cool, as the amount of power needed to operate those systems increases. 

When designing a heat exchanger, an engineer should not only consider thermal performance, but also external influences that can negatively impact thermal performance, such as fouling.

In a refrigeration circuit, the evaporator coil plays a critical role. Part of its responsibility is creating the controlled pressure drop necessary for the refrigerant to change phase, the bulk of which occurs via the system’s metering device, such as a thermostatic expansion valve (TXV).

For low-temperature hydronic systems, systems in which chillers and AHUs are located outdoors, or other equipment used in low-temperature processes, some form of glycol is a critical ingredient. It works to lower the fluid’s freezing temperature, enabling lower-temperature operation and preventing freezing.

There are terrific braze joints, awful braze joints, and everything in between. Today, we’ll examine one type of defect that can have devastating effects on joint integrity – flux entrapment.

This article has been updated. It is accurate as of 9/23/20.

Heat exchangers used for different applications need different design features. For example, in industries like pulp and paper, lower fins per inch (FPI) are often included to reduce airside fouling and to make for easier cleaning. Other applications such as the military are often concerned with weight, which impacts material selection. For this post, we're going to focus on some unique design choices we often include when building heat exchangers for the refrigerated storage of potatoes, onions, beets and other vegetables.

In many of the industries we serve, heat exchangers made with copper tubes and aluminum fin are extremely popular, and very often, these materials are a terrific choice. But copper and aluminum aren’t suited for everything. At Super Radiator Coils, the needs of many of our customers often dictate that we explore and understand alternative materials.

In fin tube heat exchangers, the fluid (gas/water/glycol/refrigerant/etc.) circulating through the coil’s tubes is extremely important for the coil’s overall performance – it’s half the battle, along with airside heat transfer. The degree to which the fluid contacts the tube walls affects the coil’s performance and influences a system's overall efficiency – the more the fluid comes into contact with the tube wall, the better – and more economical – the heat transfer.