Rotating heat exchanger with improved heat transfer efficiency

A method for heat transfer by a rotary regenerative heat exchanger, comprising:

• passing flow axially through a rotor, the rotor arranged between at least two separated fluid flow passages, each flow passage connected to a sector part of the rotor;
• and
• flowing a fluid through a plurality of channels in said rotor, each of said plurality of channels having a cross sectional area in the range 0.005-0.1 cm2 and enclosed by heat transfer and heat accumulating surfaces forming a plurality of individual channels in said rotor, wherein
• said heat transfer and heat accumulating surfaces of said plurality of channels provided in a material such that an average axial thermal conductivity is less than 100 W/mK arranged to reduce the Longitudinal Heat Conductivity (LHC) of said rotor.