unit 31 Gas

A furnace with a vertical air flow through the heat exchanger and the blower compartment beneath the heat exchanger is called a(n) ____.

• upflow

• downflow

• low boy

• horizontal

The orifice is a precisely sized hole in the ____.

• manifold

• spud

• burner tube

• combustion chamber

Most gas furnaces and appliances use a(n) ____ burner.

• compressed

• hybrid

• pressurized

• atmospheric

The proper color of a gas flame is ____.

• sharp all blue

• lazy all blue

• blue with slight orange tips

• lazy with yellow tips

A condensing gas furnace uses ____ from a condensing type heat exchanger to increase the furnace efficiency.

• sensible heat

• latent heat

• superheat

• superheat

In a conventional gas furnace, the hot flue gases are ____.

• forced out a PVC vent with a blower

• recycled through a secondary heat exchanger and then vented through a draft diverter

• forced through a type B vent by a blower

• vented by natural convection

Primary air adjusters on atmospheric type gas burners are usually ____.

• butterfly shutters

• sliding sleeves

• spoiler screws

• all of the above

Liquified petroleum (LP) is heavier than air and can cause suffocation if not handled properly.

• True

• False

A gas furnace designed for use with natural gas can be used with liquified petroleum (LP) with no system modifications.

• true

• false

In the USA, natural gas suppliers supply gas with a heat content of about 1,050 Btu/cu. ft.

• true

• false