Propane is ______ than air

Which of the following heating method directly heats objects in the room, but does not directly warm the room air.

Antifreeze ______ solution is specially formulated for hot water heating systems

In heat pump, a _____ absorbs heat from the outdoor air and transfers it to indoor:

Mid-efficiency oil furnaces can have seasonal efficiencies of approximately ______:

A correct draft is essential for efficient burner operation

Fire tube boilers, systems are simple and easy to construct and are generally used in low-pressure applications:

The temperature at which wax crystals begin to form in oil is ______

______ reading refers to the draft within the chimney piping:

Replacing the conventional burner with a flame retention head burner will save _____ on the fuel:

Aluminum tubing or castiron fittings should be used for the main gas line.

LPG has a specific gravity of ______: