Mitsubishi Electric has developed an aluminum vertical flat tube (VFT) design that improves heat exchanger performance in heat-pump air conditioners used for heating and cooling.
The new heat exchanger combines small-diameter flat tubes arranged vertically and compactly with a high-performance refrigerant distributor with a double-tube structure that evenly distributes refrigerant.
Compared to conventional aluminum horizontal flat tube (HFT) heat exchangers, Mitsubishi Electric claims a 40 per cent improvement in performance from the new VFT heat exchanger and a reduction of 20 per cent in refrigerant charge.
The company also says it has used proprietary analysis technology to develop a new fin design which significantly improves drainage, eliminating the problem of melted frost water freezing on the fins and reducing air contact with the heat exchanger (which reduces performance).
Traditional heat-pump air conditioners use fluorocarbon refrigerants that contribute to global warming and reducing the refrigerant charge tends to lower heat exchanger performance.
Conventional HFT heat exchangers also use a large number of flat tubes, but the design suffers from low heat exchanger performance because it does not evenly distribute the refrigerant, a mixture of gas and liquid under the influence of gravity.
