Through a comparative analysis mainly in an economical way between centralized heating and gas-fired unit heating, holds that the gas-fired unit heating can save investment,create much more comfort, save space and energy, charge the user for heating conveniently and accurately than centralized heating.

From analysis of mass, momentum and energy flux balance equations at inner and outer edges of the Knudsen layer using the Chapman Enskog velocity distribution function, the system of slip boundary equations with wall injection and catalysis in a multicomponent gas mixture is derived in a general form.

This paper probes into the main features, existing problems, and use circumstances of different kinds of the heating forms, and further analyzes the possibility and prospect of the diversifying heating.