What is the minimum horizontal clearance between an air intake and a gas relief device?

What is the minimum horizontal clearance between an air intake and a gas relief device?

• A. 2 m
• B. 3 m
• C. 4 m
• D. 5 m

Answer: (B)

The point of this rule is to prevent combustion air from being contaminated by exhaust or gas releases. An air intake pulls in outdoor air for appliances, so if a gas relief device vent is too close, wind can push or pull fumes right into the intake, causing improper combustion or a hazardous backdraft. Setting a minimum horizontal clearance of three meters (about ten feet) keeps enough distance so that exhaust and any released gas are unlikely to be drawn into the intake under normal conditions. Distances shorter than this increase risk, while larger distances aren’t typically required by the minimum rule. Always check local code for any site-specific tweaks.

The point of this rule is to prevent combustion air from being contaminated by exhaust or gas releases. An air intake pulls in outdoor air for appliances, so if a gas relief device vent is too close, wind can push or pull fumes right into the intake, causing improper combustion or a hazardous backdraft. Setting a minimum horizontal clearance of three meters (about ten feet) keeps enough distance so that exhaust and any released gas are unlikely to be drawn into the intake under normal conditions. Distances shorter than this increase risk, while larger distances aren’t typically required by the minimum rule. Always check local code for any site-specific tweaks.