Promising adhesive-based joining technology for residential and commercial HVAC&R applications

Abstract

Vapor compression offers a more energy-efficient method of heating compared with traditional systems. Vapor compression system not only reduces carbon emissions but also helps lower utility bills by optimizing the consumption of electricity for heating and cooling. The overall cost-effectiveness of these technologies is influenced by factors such as system design, installation quality, and the type of heat exchanger used. Because of their energy-intensive manufacturing process, heat exchangers constitute a significant portion of the cost of HVAC and refrigeration systems. This study reports the experimental results of an adhesively bonded heat exchanger of a residential-scale vapor compression. Heat exchanger joints with good bond strength were constructed with a cutting-edge epoxy adhesive to explore its effectiveness in creating durable connections while simultaneously reducing the occurrence of refrigerant leaks. This joining material and technology was assessed for chemical compatibility and material stability via two approaches: (1) an ASHRAE Standard 97 sealed glass tube test to determine the chemical stability of the metal coupons bonded by the adhesive, and (2) thermal cycling and field unit assessments of a residential-scale vapor compression system. The adhesive joints demonstrated good vibration and thermal fatigue resistance in rigorous testing with an R-410A-charged Vapor compression system under a wide range of thermal cycling environments, and no sign of degradation or failure was observed after subjecting the vapor compression unit to up to 125,000 cycles (equivalent to 5 years of system life).