FC Safety Standards & Codes for Furnace Systems 2

Question 1

According to NFPA 54, what is the minimum clearance required between a gas furnace and combustible materials on the sides when the manufacturer's label specifies 0 inches?

Accepted Answer

0 inches as labeled

Answer

NFPA 54 allows the clearance listed on the appliance label to govern; if the label states 0 inches, that clearance is permitted.

Question 2

Which ANSI standard governs the safety requirements for gas-fired gravity and fan-assisted gravity furnaces?

Accepted Answer

ANSI Z21.47

Answer

ANSI Z21.47 specifically covers safety requirements for gas-fired central furnaces, including gravity and fan-assisted types.

Question 3

Under the International Mechanical Code (IMC), what is the maximum length allowed for a dryer exhaust duct before a length reduction factor must be applied for each 90-degree elbow?

Accepted Answer

25 feet total equivalent length

Answer

The IMC allows a maximum 25-foot equivalent duct length for dryer exhausts, with each 90-degree elbow reducing the allowable length by 5 feet.

Question 4

What does the 'B' in a Type B gas vent designation indicate?

Accepted Answer

Double-wall vent for natural-draft appliances only

Answer

Type B vents are double-wall, factory-built vents listed for use with natural-draft (Category I) gas appliances only.

Question 5

According to the National Fuel Gas Code (NFPA 54), which condition requires a furnace to be equipped with a manual reset high-limit control?

Accepted Answer

When the furnace supply air temperature can exceed 250°F

Answer

A manual-reset high-limit is required when furnace supply air temperatures can exceed 250°F to prevent hazardous overheating conditions.

(FC) Furnace Installation and Maintenance Certification Practice Test

(FC) Furnace Installation and Maintenance Certification Practice Test

FC Safety Standards & Codes for Furnace Systems 2