propane vs natural gas

[Bird]

Like Egon said, they are different products. However, in some cases, they can be mixed. When I was doing gas leakage surveys, I did one in an area of Pennsylvania in which the pipeline bringing the natural gas to the town from the cross country pipeline was not big enough to allow enough volume through in some cold spells during the winter. And when that happened, they had a special set up to inject some propane into the natural gas lines. I don't remember what the ratio was, but it was a relatively small amount of propane added to the natural gas.

[Pat]

Well, while we are picking on the new guy (Swines) let me say this:

When you said, "Delivered propane is a lower BTU heat source - but the liquid will change to a gas at low temperatures so you will always have heat. "

You may have been well intentioned but you were seriously misinformed.

With propane in an outdoor tank you are subject to loss of service at low temperatures. The vapor pressure of propane goes to zero as the temperature of the propane drops to -44F (For Egon: -40F = -40 C)

When in the USAF stationed at Minot, North Dakota I was out in -47F temps. A temp of -40 or lower is not unusual for Minnesota, Wisconsin, North Dakota, Montana, and so forth.

As the temp gets down the pressure in the propane tank goes down until at -44 there is no pressure. If you open a valve to the air there it no gas pressure and no big blast of gas is bled off into the atmosphere.

So when it gets cold in the frozen north, propane tanks stop supplying fuel under their own pressure. Folks have been known to build a fire next to the propane tank to get some pressure so the stove in the house can be lit.

Pat

[RonL]

http://en.wikipedia.org/wiki/Natural_gas

[egon]

Well; if the hydro is till available usually a light bulb under the tank regulator cover will suffice! [img]/forums/images/icons/grin.gif[/img]

Egon [img]/forums/images/icons/grin.gif[/img] [img]/forums/images/icons/grin.gif[/img]

[Pat]

Egon, I don't understand what you mean "if the hydro is still available.)

If you are trying to keep the regulator thawed the light bulb would probably work. If you use a lot of gas there is significant cooling of the tank as the heat of vaporization has to come from somewhere. If it is already at or below the zero pressure temp than the tank just won't supply gas.

Pat

[egon]

Up here in Canada we refer to electricity as "Hydo" probably because of water power generation. [img]/forums/images/icons/grin.gif[/img]

Egon [img]/forums/images/icons/grin.gif[/img]

[Pat]

Egon, Sorry about that but hydro really had me confused. Makes sense now that you explain it, mostly. I thought I was a cunning linguist but apparently don't even have a good handle on the idiomatic utterances of my fond neighbors to the north.

Pat

[zuiko]

I would find out the current per-therm price they want for the natural gas and compare to the current per-gallon price for propane from your dealer... Propane has something like 92,000 btus per gallon. So if you multiply the per-gallon price by 1.08 that will give you a price to compare to therms.

If it is close I would probably stick with propane, since you are bound to have a few dollars in fixed costs added to your natural gas bill every month and there is the cost of putting in the line as well. OTOH, you can reclaim a little bit of property by losing the propane tank(s).

Another thing to consider is that you will have to re-jet or replace your propane appliances. Most (stoves, furnace/boiler) should have natural gas orfices available. Not sure about water heaters... those are usually sold as two separate models. You may also have gas piping issues. You need more volume of gas to provide the same BTUs, so depending on the size of you gas supply pipes inside the house now, you may have to replace them to go to natural gas.