FC FC Venting & Exhaust Systems

Question 1

Which furnace venting category uses PVC plastic pipe for the flue because flue gas temperatures are low?

Accepted Answer

Category IV

Answer

Category I

Answer

Category II

Answer

Category III

Question 2

What is the minimum slope per foot required for horizontal PVC vent pipe on a condensing furnace to allow condensate to drain back to the furnace?

Accepted Answer

1/4 inch per foot toward the furnace

Answer

1/16 inch per foot

Answer

1/2 inch per foot away from the furnace

Answer

No slope required

Question 3

How far must a direct-vent (concentric) termination kit terminate above the ground in a US snow region?

Accepted Answer

18 inches

Answer

6 inches

Answer

12 inches

Answer

24 inches

Question 4

What is the purpose of the concentric vent system on a direct-vent condensing furnace?

Accepted Answer

To use one pipe for exhaust and a surrounding outer pipe for combustion air intake

Answer

To save duct space by combining supply and return

Answer

To increase combustion efficiency with preheated air only

Answer

To allow longer vent runs

Question 5

A Category I naturally venting furnace must be vented with which type of material?

Accepted Answer

Type B double-wall metal vent pipe

Answer

Schedule 40 PVC pipe

Answer

Single-wall galvanized connector only

Answer

Stainless steel class IIb liner

Question 6

What is the maximum length of single-wall metal connector pipe allowed between a Category I furnace and a Type B vent or masonry chimney?

Accepted Answer

6 feet

Answer

10 feet

Answer

No limit if slope is maintained

Answer

3 feet