Whats wrong with running propane in a natural gas forced air furnace?
and what can be done to make it safe?
The orifice needs to be changed
Why?
They’re different sizes but the gas valve may need to be adjusted or changed also.
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?
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.
Propane his heavier than air and denser than Natural Gas.
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.
You do need a HVAC tech if your asking about running propane in a natural gas appliance.
conversion kits are available.
As are links explaining the different properties of each gas. http://www.naturalhandyman.com/iip/infxtra/infgas.shtm
the heating value of propane is approximately 3 times higher than natural gas, therefore the orfice size is smaller since less gas is required.
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. . .
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
NATURAL GAS VS. PROPANE
Most people are going to know which gas to use. However, for those that do not have either gas, here is the choice.
Natural gas is more commonly found in new construction and in more developed areas. If you already have natural gas running to your home or building, it is probably more cost effective to have a gas line professional run a line to your fireplace or room where the gas fireplace, logs, stove or heater will be used. Natural gas yields about 1000 BTUs per cubic foot.
LP ( also called propane) is effective for those that do not have ready access to natural gas, in rural localities, if there is a desire for the appliance to be semi-portable, or if some sort of central propane supply tank is available. Propane tanks should always be stored outdoors in a way to avoid extremely high temperatures. Propane is sold by the pound (or gallon) and delivers 21,560 BTUs per pound (or 91,500 BTUs per gallon.) It yields about 2,500 BTUs per cubic foot (vaporized).
NOTE: We often have people ask about converting a unit from one gas to another. The hoses, lines, control valves, and orifices on burners for each gas are quite different in size. Some gas log manufacturers offer conversion kits for some items. However, vent free appliances cannot be converted. Propane is roughly 3.5 times heavier than natural gas therefore its regulators, gas jet orifices and even its control valves are often different versus and the same piece of equipment using natural gas.
NEVER ATTEMPT TO ATTACH A PROPANE GAS SOURCE TO ANY NATURAL GAS APPLIANCE. THIS WILL RESULT IN FLAMES 2-4 TIMES HIGHER THAN IS CORRECT AND COULD BE A VERY DANGEROUS, LIFE-THREATENING FIRE HAZARD.
Attaching natural gas to a propane appliance is of little good. The pilot light probably won’t even light.
http://www.firechim.citymax.com/articles/article/1474175/15881.htm
Ok. How about this… Other than from being knocked over, do you know why larger propane tanks are horizontal?
Joe, what! no LEL and UEL?
Thats some good info Brian, Thanks