Help Gas pressure regulator?

Hi,

I want to install a 400,00 btu modine unit heater in the greenhouse. (which is 80 feet away from the outside gas connection). I have 5 psi (35kpa) gas coming to the entrance of the greenhouse. The modine manual recommends 6-7" W.C.

Once I add the pressure regulator at the entrance to the greenhouse. Do i look at the 0.60 specific gravity / .30" w.c. pressure drop chart for the gas pipe sizing after that? What im trying to say, is my piping going to be smaller because i have 5 psi going into the pressure regulator? or it doesn't matter because the modine unit heater could only handle 0.25 psi 7" w.c.

Or could I install a indoor pressure regulator by the modine unit heater? I personally wanted to install the pressure regulator outside in case if something ever goes wrong with it. And the environment is high humidity. If you could How close could you install the pressure regulator to the modine unit heater. It is 10 feet above the ground.

Any help or info will be greatly appreciated

 

Yes, you look at the flow chart for the pressure and flow volume that the pipe will be handling. So, in your case the 5 psi pipe will likely be smaller in diameter than the piping exiting the regulator and moving gas at much lower pressure.