510.3.4.4

[retire09]

This says a vent connector serving a natural draft appliance cannot connect to a mechanical draft system operating under pressure.

Does this include a natural draft water heater connected to a common vent with a power assist Modine type unit heater in a garage?

 

[steveray]

Which code are you in?

IMC 804.3.6 Exhauster connections.

An appliance vented by natural draft shall not be connected into a vent, chimney or vent connector on the discharge side of a mechanical flue exhauster.

 

[retire09]

2009 UPC.

I don't beveive a power assist exhaust is the same a a echanical draft system.

I beleive it is allowed.

 

[Gregg Harris]

2009 UPC.I don't beveive a power assist exhaust is the same a a echanical draft system.

I beleive it is allowed.

They are not the same. and both the natural draft water heater and the Modine are not positive pressure.

 

[steveray]

803.7 Connectors serving two or more appliances.

Where two or more connectors enter a common vent or chimney, the smaller connector shall enter at the highest level consistent with available head room or clearance to combustible material.

801.14 Connections to exhauster.

All appliance connections to a chimney or vent equipped with a power exhauster shall be made on the inlet side of the exhauster. All joints and piping on the positive pressure side of the exhauster shall be listed for positive pressure applications as specified by the manufacturer’s installation instructions for the exhauster.

That is most of what I can find for multi appliances....