Gas line question

[K13]

I have searched and didn't find a specific answer to my question. I am installing a 45,000 btu heater in my detached garage. There is already a 3/4" gas line run to the garage but my question is should I contunue with the 3/4" pipe or can I used 1/2" from the garage connection to the heater. It's about 22 feet from the valve to the heater. I plan on using black pipe.

Thanks

 

[rickairmedic]

On a 45,000 BTU unit and thata short a distance you will be fine with 1/2" pipe.


Rick

 

[K13]

Thanks. That's what I thought but it's nice to have someone who actually knows confirm it.

 

[Junkman]

Not certain if it makes a difference between Natural Gas and Propane. I tend to over size when in doubt. My propane furnace would not function properly when it was extremely cold, until the gas line was replaced with a larger one. The pressures would drop when it was very cold, and the furnace would have a hard time lighting.. For the small difference in cost, I would go with the larger size.

 

[rickairmedic]

Junk it does make a differance propane runs at a higher pressure and needs the bigger line he will be fine on NG with 1/2" . A NG gas valve runs at 3.5" water column Propane runs closer to 13" water column .


Rick

 

[bochnak]

You'll be fine. Here is a thread I started on sizing a poly line for 60k btu over 100', and 3/4" was sufficient.

http://www.garagejournal.com/forum/showthread.php?t=22998

 

[Torque1st]

Here is a table:
http://www.tanklesswaterheaters.com/sizingtable.html

 

[jhchoppers]

Plastic Gas Line

https://keithspecialty.com/gas.line.htm