Why Microtubes

The future of high-performance heat exchangers starts with Mezzo Microtubes.

Learn how and why microtubes make a difference.


Microtube heat exchangers are:

Microtubes provide extremely high performance across a wide array of applications. The ultimate reason for selecting microtubes varies by application, but in all cases, Mezzo provides its customers with industry-leading performance.


What is Mezzo Microtube Technology?

Mezzo Microtube: A tube with a diameter ranging from 0.2 to 3.0 mm. Most products fall between 0.5 and 2.0 mm in diameter.

Material: Various stainless steels, superalloys, titanium, and polymers.

A microtube heat exchanger core typically comprises of two tube sheets, which are planar and parallel to each other, and are connected by hundreds to tens of thousands of microtubes. These microtubes allow for the flow of one fluid inside them, while the other fluid flows over the outside of the tubes.

To support the tubes and guide shell-side flow through the core, additional components like header tanks, shells, midplates, baffles, and side plates are used.

Joining the tubes to the tube sheets is achieved by using various proprietary methods.

Several architectures are available for microtube heat exchangers, including multiple pass crossflow shell side, multiple pass crossflow tube side, cylindrical or rectangular cores, and pure counterflow (for cases where extremely high effectiveness is needed), among others. Unlike other heat exchangers that rely on fins to transfer heat, microtube heat exchangers are sometimes called “primary surface” heat exchangers, as they do not use fins to transfer heat from one fluid to the other.

Why Use

Mezzo Microtube

Simple scaling laws show that microtubes provide significantly more UA/volume (KW/K-m3) than heat exchangers that utilize larger diameter tubes or larger characteristic channel dimensions. The UA/volume scales with tube diameter approximately as 1/D2. So, a heat exchanger with 1.0 mm diameter microtubes will have a UA/volume ratio about 100 times greater than a heat exchanger with 10 mm diameter conventional-scale tubes.

The volume, weight and cost savings associated with a compact microtube core in a high-pressure application are significant.
Some in-line patterns that Mezzo uses for its radiator-style applications provide very attractive combinations of high thermal performance, low air-side pressure drop, and excellent resistance to air-side fouling.
Tightly packed microtube arrays provide very compact solutions in liquid-liquid applications, and liquid-gas applications. Interestingly, the pressure drops in these products often compares favorably with pressure drops across more conventional manufacturing approaches.
The thermal conductivity of the tubing usually has minimal effect on overall heat transfer­— the thermal resistance through the tube wall is often negligible independent of whether the tube is made of stainless steel or a polymer.
“Pure” counterflow microtube recuperators for certain cryogenic applications offer a cost- effective, compact, low-mass solution.
In cases where the combination of temperature and pressure exceeds the practical limits of stainless steel, Mezzo has access to high temperature nickel alloy microtubes (Inconel, Haynes 238, etc). Microtube solutions are inherently advantageous for high pressure applications and lead to compact, low mass designs that minimize the use of the expensive materials from which these heat exchangers must be made. All these factors lead to a good value proposition for the customer.
Phase Change Material (PCM) heat exchangers made using microtubes typically offer substantial weight savings over alternative designs.