generator clearance

[ss electric1]

generator distance from building. i use 10 foot clearance.
where does it state this rule?
thanks for info.

 

[Daja7]

generator distance from building. i use 10 foot clearance.
where does it state this rule?
thanks for info.

Manufacurers installation instructions along with local code. Generac 18" kohler, Briggs and Cummins onan (i think) is 5 feet. All cannot be within 5 feet of any opening in the house, no closer that 10 feet to propane tank and three feet from nat. gas meter.

 

[JoeStillman]

There are also rules about how close the exhaust can be to an operable window or louver. Check with the mechanical department - this may be where the 10' rule comes from.

 

[Shoe]

It will also depend on if you are storing fuel (sub-base) as a part of the generator assembly. You are then bound by requirements of the fuel storage guidelines (NFPA 37 and possibly others) that may dictate the distance requirements from a structure. It often depends on the building Type classification as to what clearances are required (combustible versus non-combustible etc.).

 

[Npstewart]

10' from from the building in my opinion is excessive. Around here, 10' from the building would probably put you 5' from your neighbor's house.

Over the years I complied a little list that has never failed me which is composed of requirements from manufacturers data, NFPA 37 & 110, the NEC & AHJ requirements.

• 18" between the generator & the house/shrubs
• 36" in front of electrical components required to be accessed
• 60" from soffits
• 60" from operable windows
• 120" from building fresh air intakes (if any)

See attached.

 

[infinity]

So a window could be directly behind the unit as long as it's 60" above the top?

 

[GoldDigger]

So a window could be directly behind the unit as long as it's 60" above the top?

If the only applicable factors are the literal wording on the posted recommendation drawing, yes. But it is not clear what the wording of any actual applicable code sections is. Possibly one of them states "measured horizontally" or "horizontal distance" for example.
The conditions will actually vary somewhat depending on what you are concerned about.
Propane falls, while NG(methane +) and CO rise, for example.