Another question for Y'all

Whats wrong with running propane in a natural gas forced air furnace?
and what can be done to make it safe?

[Brian E. Kelly]

The orifice needs to be changed

Originally Posted by bkelly2

The orifice needs to be changed

Why?

[Larry D. Kage]

Originally Posted by twheeler

Why?

They're different sizes but the gas valve may need to be adjusted or changed also.

[Brian E. Kelly]

Originally Posted by twheeler

Why?

Tyrone get a qualified HVAC technician to evaluate your furnace.

That still doesn't answer the question, I know they are different sizes, but why would they even need to be different sizes?

Originally Posted by bkelly2

Tyrone get a qualified HVAC technician to evaluate your furnace.

I don't need a HVAC tech to evaluate, I am just trying to drum up some posts that will challenge our minds, and maybe even help someone who is struggling with the answers.

[Brian E. Kelly]

Propane his heavier than air and denser than Natural Gas.

[John W. Springstead]

Propane and natural gases are delivered at different pressures for one thing.
Natural gas is lower pressure than L.P. Plus I'm sure their properties and make up are different. Therefore, different size orifices.

[Brian E. Kelly]

Originally Posted by twheeler

I don't need a HVAC tech to evaluate, I am just trying to drum up some posts that will challenge our minds, and maybe even help someone who is struggling with the answers.

You do need a HVAC tech if your asking about running propane in a natural gas appliance.

conversion kits are available.

[Brian E. Kelly]

Originally Posted by twheeler

conversion kits are available.

As are links explaining the different properties of each gas. http://www.naturalhandyman.com/iip/infxtra/infgas.shtm

[JASON S. LOVELACE]

the heating value of propane is approximately 3 times higher than natural gas, therefore the orfice size is smaller since less gas is required.

[Jeffrey R. Pope]

The difference has to do with the burn temps of each gas (I don't have the #'s in front of me).

You can burn out the appliance if you are burning the wrong fuel. . .

[Joseph Hagarty, CMI]

Fuel-Natural Gas ( CH4 )
- Comprised mainly of methane (81%)
- Lighter than air (specific gravity .65)
- BTU content/cu.ft. =700 to 1200
- Ignition temperature of 1100° to 1200°F
- Typical manifold pressure = 3.5” WC

Propane ( C3H8 )
- Comprised mainly of propane (95%)
- Heavier than air (specific gravity 1.53)
- BTU content/cu.ft. =2500 to 2700
- Ignition temperature of 920° to 1020°F
- Typical Manifold pressure = 11” WC