common venting oil and gas units

Alan R. Mercurio_3

It's probably best to check with your local code enforcement but here's what's written in NFPA - 211

6-8.3 Gas utilization appliances and appliances burning liquid fuel shall be permitted to be connected to one chimney flue through separate openings or shall be permitted to be connected through a single opening, provided they are joined by a suitable fitting located as close as practicable to the chimney and provided both of the following apply:

(1) Sufficient draft is available for the safe combustion of each appliance and for the removal of all products of combustion.

(2) The appliances so connected are equipped with primary safety controls and all appliances are located in the same room.

6-8.4 If two or more openings are provided into one chimney flue, They shall be at different levels, and the smaller connection shall enter at the highest level consistent with available head room or clearances to combustible material.

Hope this helps.

Your friend in the industry,<BR>Alan R. Mercurio<BR><BR><a href="http://oiltechtalk.com">Oil Tech Talk</a>

Rusty_2

common venting oil and gas units

looking for the code that prohibits common venting of oil and gas appliances (together) in a single chimney. I seem to remember such a code, and the practice is commonly refered to as a violation in my area, but I am unable to locate the actual code.

Maine Ken

Where are you?

Jack_21

NFPA 31 allows it

The prohibition on common venting is for solid fuel and another source whether oil or gas (unless it is a tested and listed appliance approved for such use, as in a wood/oil boiler/furnace)

Common venting gets tricky as the gas side has to meet NFPA 54 for sizing/capacity/lining and the oil side may need help too. If you reline an oil/gas stack you would of course have to use a SS liner. Aluminum is verboten!

The gas should connect one ft above the oil connector to he vertical portion of the chimney. If that is not possible then put the gas as close to the chimney connector as possible and use a wye fitting to properly orient the flue gases from the lower btu appliance (I'm assuming it is a gas waer heater). If your local inspector pushes back on this type system I'd try to get pre-approval.