Is propane a heavy gas?

[beelzerob]

We're getting a propane kitchen stove, and I've got the wire for a sensor...but it suddenly occured to me that propane might be heavier than air, in which case a ceiling mounted sensor might not be of much use until....well, *boom*.

If it's a heavier gas, then I can probably find some wall out of the way down near the floor to put the wire.

 

[me2]

We're getting a propane kitchen stove, and I've got the wire for a sensor...but it suddenly occured to me that propane might be heavier than air, in which case a ceiling mounted sensor might not be of much use until....well, *boom*.

If it's a heavier gas, then I can probably find some wall out of the way down near the floor to put the wire.

Yes

 

[CollinR]

Much heavier.

I have never done jack about propane so no help other then it's heavier.

 

[ctay]

I wouldn't call it heavy... It maybe just put on a little water weight...

 

[rfdesq]

Take a look at this site http://www.rversonline.org/02Propane.html.

 

[beelzerob]

Take a look at this site http://www.rversonline.org/02Propane.html.

Thanks, useful link.

Propane gas detector, in addition to smoke detector, now standard in all RV units. It's always located close to the floor, since propane is heavier than air. [However this theory is being re-examined because propane travels with convection -- some tests have shown placing the detector at a higher point may in some cases be more effective.]

Well, except for that part... Nothing like a little ambiguity thrown in....

I don't know where I would put this sensor then, except down on the baseboard of cabinets. There really is no wall close.

Maybe I'll just decide that we won't have an "accident".

 

[aehusted]

Maybe I'll just decide that we won't have an "accident".

This might not be such a bad idea. One thing to consider, as far as safety goes, is the size of your home and the quality of the ventilation. These leaks are very dangerous in mobile homes because it is such a small confined volume with little circulation. While I am not an expert on these matters, I think that these sensors are most likely designed for this type of situation.

From reading through this board a lot and from personal experiences, water is a much more likely cause of "accidents" than anything else. Personally, I will spend my time and money on water hazards first, but again - I am not an expert.

 

[beelzerob]

Well, honestly what boggles my mind the most is that gas/propane kitchen stoves just don't have some basic safety features. Our old gas furnace would stop trying to light itself if it didn't sense that a flame was going within about 10 seconds of letting in the gas....I'm not aware of anything similar with our stove. Basically, you should not be able to ever just leave gas pouring on without a flame there.

What I'd be happy with, at a minimum, is just some kind of lockout for the burner controls. It's bad enough they have to put them at kid level, couldn't they simply require that you hit a button on the top/back first before you can use that control, so kids can't affect them at all??

*groan* Of course, with all this complaining, you might wonder why we're getting one in the first place. Heck, we just like cooking with it better. I just wish they had a bit more safety to them.

 

[rfdesq]

I don't know where I would put this sensor then, except down on the baseboard of cabinets. There really is no wall close.

I don't see a problem with two detectors. One down low and one higher up for convection currents.

 

[BraveSirRobbin]

Well, not an expert, but strictly going my molecular weights:

Air is 78% Nitrogen, 21% Oxygen, and 1% Msc.

Mass of N2: 0.78 x 28.02 = 21.86
Mass of O2: 0.21 x 32.00 = 6.72

So weight is 21.86 + 6.72 = 28.58

Propane is C3H8 so:

Weight is 3 ( 12.01) + 8 (1.01) = 44.11

So propane is heavier than air.

 

[Mark S.]

While propane gas is indeed a little heavier than air, mounting a sensor on the floor will not necessarily do you any good. Because propane escapes under pressure, the "refrigeration effect" and jet velocity can create convection currents that can take it just about anywhere, but this "swirl" at the release area will result in a high concentration near the source of the leak. Your best bet is simply to mount the sensor where you would expect the propane to leak - close to fittings, valves, etc. - the concentration will be highest there and will give you the earliest warning.

Mark

 

[Sacedog]

Maybe I'll just decide that we won't have an "accident".

This might not be such a bad idea. One thing to consider, as far as safety goes, is the size of your home and the quality of the ventilation. These leaks are very dangerous in mobile homes because it is such a small confined volume with little circulation. While I am not an expert on these matters, I think that these sensors are most likely designed for this type of situation.

From reading through this board a lot and from personal experiences, water is a much more likely cause of "accidents" than anything else. Personally, I will spend my time and money on water hazards first, but again - I am not an expert.

I strongly disagree. In our last house, my wife turned off the gas cooktop one night, and must have bumped it back on. That was right when we went to bed. I happened to get up that night, and go downstairs, and could not believe how much gas I smelled. I got the family out, and opened all of the windows, and luckily nobody got hurt. I am definately putting a gas detector in my new house...in fact, it actually arrived in the mail today! I will probably mount my at counter height, near the cooktop and oven.

 

[aehusted]

I just came across this post randomly and remembered a story that is worth sharing here.

A friend of mine owns a restaurant that is in a big old colonial stone house. In the basement there is a large private banquet room, in the middle of which is an old well. One night after a big party, the staff was cleaning up the basement and one of them dropped a cigarette butt into the well through a crack in one of the boards covering it up. Well as it turns out, there was a very small leak in the gas line that supplied the kitchen on the floor above and the undetected leaking gas all accumulated in the lowest point of the house: the well. The damage from the resulting explosion and fire was thankfully minimal.

I doubt many of you have a well in the basement, but this is something to think about when you are planning your gas detector placement.

 

[beelzerob]

Heh...nope, no well. Bet that was a shock to them, though, and I hope he learned a little bit about littering! B)

I could not be any more disappointed and disgusted with our gas range (it's a whirlpool I think...maybe a Maytag). One thing I discovered is that if you move the knob past "Light" and just let gas pour in, you can't turn the knob back to off without passing past Light again.

So, the knob gets left on, the gas alarm goes off, you run downstairs to turn the knob to Off, and *clickclickclick* *BOOM*!

I hate that stove. Last time the wife gets to pick that out by herself.

 

[gatchel]

Take a look at this site http://www.rversonline.org/02Propane.html.

That really is a good link.