Hi Paloma,

As you have discovered, Natural Gas will give you roughly 25% more heat generation at equivalent pressure relative to Liquid Propane. So when converting your roast profiles from LP to NG you'll want to reduce your gas pressure values to achieve the same roast curves.

Seems like you are already well on your way to adjusting your gas pressure settings though.

To put too fine a point on Karsten's response, Natural gas is thinner and lighter than LP gas. The BTU content of natural gas is about 1000 btu per cubic foot. LP delivers about 2700 btu per cubic foot.

The key here is orifice size. Because LP is a denser gas, it is delivered at a higher pressure to force a greater velocity of flow through a smaller orifice to provide more optimal mixing of air flow through the burner to increase burner efficiency.

Basically, that means clean blue flame combustion. Blue is hot and good, yellow is sooty and bad. This is exactly why we do video calls for every new installation. We need to see the burner to know everything is running the way it is supposed to.

As you have discovered, converting a open flame burner roaster from either natural gas or LP requires the operator to calibrate to a new set of pressure gas readings. This usually isn't a big deal. After a couple of days at the roaster, you'll probably be dialed in enough to forget about the difference.