Keeping Propane Tanks Warm

Discussion in 'Cold Weather Camping' started by PopUpSteve, Dec 3, 2018.

  1. J Starsky

    J Starsky Well-Known Member

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    I'm been toying with a semi dangerous idea of adding an exhaust tube from your camper furnace to reroute heat towards the tanks. Nothing 100% sealed or fully contained. I keep circling around the idea that you are creating heat from furnace exhaust and how could you recapture that towards keeping the tanks warmer than outside temps...without dying of course....
     
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  2. Spridle

    Spridle Member

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    Having a regulator with a much larger BTU rating than the furnace seems to be the trick. I played with a bunch of these things in the garage and had lots of freezing issues. One of them caused the regulator to freeze FULLY OPEN and it's a miracle I didn't blow the hell up as the construction heater turned into a raging fireball of death. With an over sized regulator I just don't seem to have the issue anymore. I have a new setup for the garage for this winter, it will be interesting to see what happens when it really gets cold. I would also note that in these garage tests, the grill tank is always in the garage with the heater. On the camper with my previously linked regulator I have camped down to about 25f so far with no issues, but have not tried colder. I have avoided a few cold weather trips because I was afraid the plastic windows would crack when opening up the pup.

    On topic but not really on topic. I replaced the squirrel cage on my older heater with the updated plastic cage and it works better with far less vibration than the older cage fan.

    I have also now experienced the cheap inverter gens and returned them, sucked it up and bought a Honda. There just isn't any comparison. But if I were camping off grid, I would be very tempted to try the Ryobi propane only generator for a few hundred bucks. You could easily charge your batteries and keep the furnace running during the day, then battery only at night.

    The other problem I've run into with heavy battery draw of the furnace running all night is my CO/LP/SMOKE detector going off in the middle of the night from a low battery condition. There is no off switch for that and it's REALLY ANNOYING.

    Bottom line for me is that if I do cold weather camping I now try to find electric sites. I still use the propane furnace as my main heat, but I have small electric heater as backup.
     
    Last edited: Dec 6, 2018
  3. JimmyM

    JimmyM Well-Known Member

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    In cold weather, the exhaust might lose so much heat by the time it gets to the LP tank it may not pose any danger at all. LP tanks are perfectly safe sitting in the shade on a 120F day in Arizona. Do you think you could possibly get that tank to 120F on a freezing night with heater exhaust? I'm not going to recommend this to anyone. But I might try it myself if I had LP pressure issues due to cold. There are charts for Btu output based on gallons of LP vs temperature. https://countryplans.com/smf/index.php?topic=10186.0
    However the frozen regulator issue seems to be gaining traction too.
     
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  4. Spridle

    Spridle Member

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    That chart is fascinating (I'm a nerd). Given that chart, instead of an auto changeover valve what we really need is a single stage regulator, with the two tanks combined to act as one. That would be the only way to get that 20K BTU out of those tanks as they start to drawn down and you are in the single digits.

    I'd make my own with quick release fittings instead, but this is essentially what you'd need to have a better shot of keeping that furnace running into the single digits. You'd give up the auto change over valve too, unless you doubled everything up with four tanks! (where is the Tim Taylor meme?)

    https://www.tractorsupply.com/tsc/p...MI2uTvxZCM3wIVxJ-zCh21aQuqEAQYAyABEgKVdvD_BwE
     
  5. J Starsky

    J Starsky Well-Known Member

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    It's the exhaust reroute and carbon dioxide that bugs me. Seem the worst way to die, death be camper mod...

    If you could pipe the warm exhaust to the bottom side of the propane tank, heat could rise past the regulator and tank to escape, and if mixing with some clean air along the way the dangers go down too. I see it like an pipe run into a 5 gallon water jug, bottom removed and the exhaust would rise up and out the mouth of the jug... I'm will you, that tank would never overheat. Mythbusters had one on a flame for a while before expand, and with a safety regulator it can't explode.

    I'm worried about the exhaust gas and killing Steve. We need a camp director 'round these parts!
     
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  6. gladecreekwy

    gladecreekwy Well-Known Member

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    No need to insulate a propane tank. I use my propane grill all winter at temps well below 0 with no issues.
     
  7. JimmyM

    JimmyM Well-Known Member

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    I'd hate to lose Steve too! But the furnace vents outside too. It would take the perfect storm of air flow to have any even get inside the camper. even a tiny airflow would sweep it away.
    On a darker note... Of all the ways to die, I think CO would be rather peaceful. Just go to sleep, never wake up. Getting caught in a farm combine. Now THAT would be an awful way to die.
     
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  8. tenttrailer

    tenttrailer Art & Joyce - Columbus, O

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    Propane tanks no mater how much propane you can go to a chart look up the psi based on the temperature of the Propane. It will normally be lower than the outside temp because of the evaperation.

    I'm not sue it's a big issue about the pressure as long as it is above 11 IWC. Which even when cold it will be a high psi number.
     
  9. JimmyM

    JimmyM Well-Known Member

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    It isn't just the the static PSI at temperature, but the ability to deliver propane at a low temperature.
     
  10. J Starsky

    J Starsky Well-Known Member

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    Farm Equipment is the scariest stuff
    [​IMG]
     
  11. PopUpSteve

    PopUpSteve Administrator

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    I appreciate that. But I would not reroute the exhaust. Firstly, shooting that under the bunkend is not a good idea IMHO and secondly, seems like a lot of effort mod-wise for little return.

    Good thread, lots of ideas and info created. I think the original problem was most likely the regulator. I think I may replace mine with the one suggested earlier.
     
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  12. Spridle

    Spridle Member

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    I'm a fan of that valve and recommend it, but keep in mind that there is also a pressure drop as the one tank runs out and it switches over, until you manually flip the valve, then you get 100% again. None of this is a problem at normal temps but it could be in the middle of the night. If you do this again, manually throwing that lever over on day 2 might be worthwhile.
     
  13. tenttrailer

    tenttrailer Art & Joyce - Columbus, O

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    I would agree with the regulator or the valve on the tank as the issue. The tank has a safety device in the valve to restrict propane flow if the line reputed, it could be that device acting up in the cold?

    We had a 2nd house for many years with an outdoor propane tank and a regulator set at 11 IWC. Temps have been below -20 below F for a few days straight and our furnace, water heater and stove have all worked fine. Now the furnace was working full time to keep up
     
    Last edited: Dec 9, 2018 at 10:20 AM
  14. tombiasi

    tombiasi Well-Known Member

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    11 WC is a low pressure supply
     
  15. tenttrailer

    tenttrailer Art & Joyce - Columbus, O

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    Yep. May be confusing. But what I was trying to say is you need a much higher pressure on the supply side. It did not need to be hot summer tank pressures. It could be high cold winter pressures. You just need these high pressures to regulate down to 11 WIC or about 1/2 psi for the systems to work.
     
  16. tombiasi

    tombiasi Well-Known Member

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    Yes but not everything is low pressure. I have a burner that takes 25 psi.
     
  17. tenttrailer

    tenttrailer Art & Joyce - Columbus, O

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    The other thing to consider is as it gets colder these little propane heaters are going to put out less heat by design. The air used in the combustion chamber is from the outside. You are sucking cold air in from the outside to burn in the combustion chamber. The burn of the propane is going to give you a X-BTU increase of heat. But if you are sucking 50 degree air vs 20 degree air from the outside, the heat exchanger temperature will be about 30 degrees lower. This will give you a drop of about 30 degrees of the air blowing out of the furnace inside the camper. In very cold temperature you will notice the difference.
     
  18. tenttrailer

    tenttrailer Art & Joyce - Columbus, O

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    Then you need about 1 PSI far lower than the supply side in cold weather which will have PSI's exceeding 60 PSI. It should no be an issue for your regulator.
     
  19. PopUpSteve

    PopUpSteve Administrator

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    Interesting, I hadn’t thought about that.
     
  20. tombiasi

    tombiasi Well-Known Member

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    Has never been a problem. Probably would show up near 0F. Just wanted to point out that not everything is low pressure.
     

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