Lead alone is not used in storing equipment, because it

Question: Fuel economy in furnaces can be achieved by
[A].

using oxygen enriched combustion air.

[B].

preheating the combustion air.

[C].

reducing the heat loss through furnace openings & doors.

[D].

all (a), (b) and (c).

Answer: Option D

Explanation:

No answer description available for this question.