Natural gas + propane furnace?

[Whoaru99]

I'd think in this day and age it would be possible to make a gas furnace that could use either natural gas or propane more or less with the flip of a switch.

Have done some browsing but don't see anything like this without having to put in a propane/air mixer.

Anyone know of a home-type furnace that would do such a thing?

[nobody05]

Buy the furnace and buy the conversion kit and bam there ya go. It doesnt take more than a 15 minits to convert most modern day furnaces

[jentz]

The new furnace we have 3 yrs old came with the conversion kit.Had to read the directions really well.Just to see where the propane jets were hidden on the new furnace.Once I found them it was a 3 minute job switching them out.The Jets are the fuel air mixture

[Tom7227]

The orifices are different for natural gas than they are for propane. I don't think you can just flip a switch,you have to change them out.

[Whoaru99]

Yeah, I understand about different jets and that conversions usually can be done that way.

Just would seem that these days it would be possible to do it with more advanced forms of metering control. Sorta like a flex fuel vehicle...they just work on either E85 or pure gas, or anything in between without any conversions or "rejetting" (yes, I know they dont use jets, per se, hence the quotes). The fuel metering detects and adjusts accordingly, automatically.

[Tom7227]

I am wondering why you would use propane if natural gas is available. I thought natural gas was incredibly cheap these days.

Just trying to learn.

On another note, I drove past place selling corn stoves last week. The parking lot was empty.

[CAMAN]

Also, how many homes are plumbed with BOTH natural gas and propane? I'm guessing the market doesn't drive any company to make/invent anything that could switch like that. Therefore you either order the furnace to run off a specific gas or make the necessary changes in the field.

[Whoaru99]

I am wondering why you would use propane if natural gas is available. I thought natural gas was incredibly cheap these days.

Just trying to learn.

I wouldn't, when natural was available. Normally I'd run on natural or electric as I do now when things are good.

If things got not so good, as during the recent storms out East, I could just flip a switch to run the heat from LP tank and use a small generator to run the blower fan plus a few lights and such. My electric heat isn't practical to run from a small generator, being 18kW of load.

So, basically, the point is emergency/back-up heating plan.

[delcecchi]

Does natural gas go out in a catastrophe? I figured it would keep going.

[Whoaru99]

Depends on the catastrophe. If leaks develop or whatever could be too low of pressure or could be shut off, etc.

[Tom7227]

Does natural gas go out in a catastrophe? I figured it would keep going.

My son is out in NY and he said they turned it off. Something about damaged buildings with appliances continuing to let out gas but there being no combustion. Pilot lights in older rigs, houses where water heaters and furnaces got moved by water, things such as that.I don't know if that is what happened in that one area where all those houses burned down but I suppose natural gas in those homes would have made things worse.

[Eric Wettschreck]

This is very do-able. The problem is the cost of manufacturing. There isn't a furnace company out there that couldn't make a dual fuel unit. However, the costs would prevent most people from buying the unit.

In the end, why would a guy drop a ton more money on a dual fuel furnace when they can buy a conversion kit for 30 bucks. Even if they had to hire a plumber or HVAC guy to do the conversion, they're still huge coin ahead.

[PurpleFloyd]

Does natural gas go out in a catastrophe? I figured it would keep going.

Even if gas is still flowing, most modern heating units require a fan to ventilate and the newer ones also have lots of electronics that would keep it from running properly if at all if the power went out. Converting to natgas would not help in that case. Unless CO poisoning isn't something the homeowner would be concerned about.

[Whoaru99]

I'm not convinced it would cost a ton more to make. Some more, sure.

OTOH, I can see a considerable retail premium for such a unit.

[Surface Tension]

If you were able to "dial an orifice" that would have to be linked to the gas source.

Meaning when you switch to one or the other, it would have to turn off and turn on the appropriate gas type with an all in one step operation. Otherwise it wouldn't fly because of the safety issue.

Because of the chances a disaster bad enough to shut off NG isn't too great (we hope),

changing out the orifice to get heat again seems simple enough.

That would be the easy part if you don't have a gas line for propane and a couple 100 lb tanks filled and ready to go. Coarse you'll need a generator too.

Since it is much more likely and even common to have a power outage.

Having a generator with a transfer switch already installed makes a power outage to power back on almost seamless.

[Whoaru99]

I was thinking bigger...min 250 gal tank, maybe 500. A 1000 gal probably just too big for where I'd have to put it. It'd take up half my back yard.

A small/medium-sized propane genset would be in the plan too for this bigger picture backup plan. Maybe something around 6-8kW.

Frankly, with the off peak electric heat rate, I haven't burned a cubic foot of natural gas in years. Matter of fact, last fall the gas company came by to replace my "defective" meter that wasn't reading any gas use.

Told them they could replace it if they wanted but the new meter will still show zero use. He looked at me funny, sort of with that dog head cocked to the side thing, so I had to tell the rest of the story about using electric heat. I don't even leave the standing pilot going on the furnace.

So, in this regard, maybe I should just do away with natural and have electric + propane. Hmmm...?

When I said just by "flipping a switch" it was a bit tongue in cheek. Turning a couple valves and such ain't no big deal. The point is mainly not to have to disassemble/reassemble, readjust, etc., etc.

[fastkaw]

Dont forget you need to set your gas psi. each time you change from

nat.gas to lp.and back. YOU NEED A MANOMETER. If the psi. is incorect

you could have a very seriously over fired burner!!!!

Also if you cant prove that the furnace was converted by a license

contractor, it may void your heat exchanger warrantie.

[nobody05]

I've seen something like that on a boiler before. You pipe it all the same but you just adjust a throttle screw on the gas valve to for Natural or Propane gas. Need to buy a 600 Dollar combustion alnalyzer to know where to put the screw for optimum efficency.

[WWW]

Would imagine there is not much call for one or they would make it. Got a garage heater that can run both with a flip of a switch. It says Glo-Warm on the front. The guy I got it from had just purchased another last fall somewhere around the twin cities.

[Whoaru99]

Apparently not. Maybe it's my million-dollar idea just given away.

[Whoaru99]

Yes and no.

Where I work we have a BIG propane tank and a propane/air mixer that kicks in in the event there is a problem with natural gas.

Propane/air mixers are readily available, unfortunately in rather large sizes, so apparently there is a demand for the ability to run natural gas equipment on propane at larger scales.

You all are not entitled to make millions on my idea.

[delcecchi]

Apparently not. Maybe it's my million-dollar idea just given away.

I hate it when I think of a great idea and find out someone beat me to it.

[basslkjohn]

I'm no survivalist with two years of food stored in an underground bunker...but I was visiting with my son last night about this very issue. He lives in Oakland. If an earthquake hits out there or we have a serious cyber-attack or huge winter storm here that knocks out power for several days (weeks) in sub-zero temps, things could get serious in a hurry. A propane tank for emergency power seems more practical than 500 gallons of gasoline on the property. If you had the conversion kit for a gas furnace and a method for converting your generator to run off propane, you could keep the house (and occupants) from freezing up.

Is there say a 500 gallon propane tank on the market?

Is it practical to convert an existing gas generator to propane?

I don't know if the natural gas line could be compromised, but I think it is possible. We know that gasoline for the generator could be in short supply or unavailable for several days. So, maybe we should think about a propane fuel supply on site. Interested in your comments. Thanks.

[WWW]

Sounds like a lot of work. Havent ran into a situation where the upper mid west has been wiped out yet. If something that bad happened I would just head to the relatives or a motel somewhere else. Might just be a good time for a vacation.

[Whoaru99]

Is there say a 500 gallon propane tank on the market?

Is it practical to convert an existing gas generator to propane?

Yes, 250, 500, and even 1000 gallon tanks are pretty common.

Yes, it is practical to convert most generators to propane, but I believe there is usually somewhat of a reduction in output. For example, units I've looked at that are available either way are rated 8kW on gasoline and 7kW on propane. Myself, for emergency backup, I'd tend toward the smaller size necessary to sustain you, even if that means somewhat reduction in convenience or lifestyle, just because your fuel will last longer. Sure, it would be great to have a 20kW genny to pretend nothing happened, but keeping that fueled for any extended duration could/will be problematic, IMO.