Bigger is not always better, and one recent example is the new MicroGroove technology, which was introduced in 2010. This technology is defined by smaller diameter copper tubing with enhanced inner surfaces for the purpose of reducing refrigerant charge, minimizing material content and improving heat transfer. Higher density refrigerants that require less volume for a given heat exchange, or hydrocarbons (where refrigerant quantity is limited), are the key applications for this technology.
The MicroGroove brand is supported and presented by the International Copper Association (ICA). ICA recently published a press release touting the advantages of MicroGroove over microchannel aluminum.