CH-24-C110 - Design and Testing of a Novel Microchannel Polymer Heat Exchanger for Applications in Residential Cooling

Liquid-to-air heat exchangers are key components in residential cooling applications. They are typically made from metal (e.g., water coils), but there has been a drive to use polymers instead due to the potential to make lighter, less costly products that are not as prone to corrosion as their traditional metal counterparts. The lower thermal conductivity of polymers, however, can compromise performance. This paper describes the development and experimental performance of a counter-flow 3D printed Microchannel Polymer Heat eXchanger (MPHX). This model builds upon a previous generation of a high efficiency heat exchanger developed by the group (Rasouli et al. 2022) in terms of scalability by integrating the liquid headers within the airflow path, which also allows the water and air flow at the inlets and outlets to be more fully counterflow. The heat exchanger consists of smaller stacks of 20 water plates which can be stacked to form a heat exchanger. A single water plate has a full water flow passage as well as half of an air flow passage on either side. The plates also have aerodynamically shaped loops that, when stacked with other plates, form headers for water flow that feed into the water passages. O-rings at the header loops at the end of each 20-plate stack provide seals between the water plates to form a unit for testing. For thermofluidic testing over a heat capacity rate ratio from about 0.5 to 1, experimental effectivenesses ranged from 0.83 to 0.99.