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.

Around 2010, the first refrigeration systems operating on transcritical (TC) CO2 (R744) – commonly called booster systems – began cropping up in North American supermarkets. Since then, usage of TC CO2 systems has grown steadily and they’ve become viable options for places like supermarkets, food warehouses, and ice rinks, as more organizations move away from traditional HFC refrigerants. Natural refrigerant market accelerator Shecco estimates that TC CO2 systems grew from 140 in 2008 (all in Europe) to more than 35,000 systems worldwide today.

Oftentimes, using stainless steel components seems like a simple solution to corrosion on coils. You may see fins or tubes or other parts of the system show signs of corrosion, and it seems that the best option is to change the coil to stainless steel, solving the corrosion problem permanently. While this seems like a simple solution to a significant problem in the HVAC, industrial, and commercial systems where coils are found, the answer to the question “should I make an all-stainless coil?” is far more complex.

In plate fin heat exchangers, the fins themselves play a critical role. They provide the extended surface area needed to achieve effective heat transfer between a gas on the finside and a fluid on the tubeside.

For commercial operations that rely on effective heat transfer, external corrosion of heat exchanger components is a major concern. When left unchecked, corrosion can significantly reduce a coil's effectiveness, but sometimes it’s difficult to know which anti-corrosion option best meets your needs.

We get asked a lot of questions about the passivation of stainless steel welds. Oftentimes, customers want to know what passivation is. Others ask if it’s necessary. Given the number of factors that such a decision hinges on, Super Radiator wants customers to understand the benefits of passivation, and also understand what’s involved in the larger process of treating stainless steel surfaces.