An ornamentaldesign for solarair heater, as shown and described.
FIG. 1 is a front end view of the solar air heater.
FIG. 2 is a section of a top perspective view of the solar air heater.
FIG. 3 is a section of the bottom perspective view of the solar air heater; and,
FIG. 4 is a top perspective view of the solar air heater.
The broken line showing is included for the purpose of illustrating environment and forms no part of the claimed design. Figures are shown broken away at the edges for the purpose of illustrating that a particular length of solar air heater forms no part of the claimed design.