Heat transfer sheets (70) for a rotary regenerative heat exchanger (10) have a alternating first and second undulation surfaces (71,81). The first and second undulation surfaces (71,81) are composed of parallel ridges (75,85) angled in alternating directions. When the heat transfer sheets (70) are stacked, they create passageways (79) between them that direct air/gas through them. The ridges (75,85) redirect the air flow near the surface of the heat transfer sheet (70) imparting turbulence reducing laminar flow to improve heat transfer. The heat transfer sheets (80) employ curved ridges (95) having valleys (97) between them that define passageways (99) that constantly redirect the air/gas flow minimizing turbulence, creating efficient heat transfer.

An adjustable rotor support with a carrier beam configured to receive a center shaft of a rotor, at least one support brace connected to the carrier beam, and an adjustment arrangement operably connected to the support brace(s). The adjustment arrangement is configured to generate movement of at least one of the support brace(s), movement of the support brace(s) generating movement of the carrier beam along an adjustment axis (A1) perpendicular to a center axis (A2) of the center shaft. The adjustment arrangement is configured to lock the support brace(s) in a position reached through the movement such that the position is maintained by the adjustment arrangement during operation of the rotor.