Bunk Canvas Condensation

Discussion in 'PopOut (Hybrids)' started by Dammitjim, Nov 5, 2012.

  1. Dammitjim

    Dammitjim New Member

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    We camped this weekend and the temperatures at night dropped to the mid 50s. From our experience in our HTT, this is the time of the year when we'll start to get condensation on the inside of the canvas because we are 7 people in our HTT. The first night we ran the heater and the fan and we had no condensation. I didn't want to run the combo on the second night because I couldn't hear the sound of the waves [8D] (we camped @ Gamble Rogers which is as close as you can get to camping on the beach). So, I didn't run anything the last night, but the following morning I woke up to my daughters laughing and saying: "It's raining inside the camper [{}=]!" It took the whole morning to get rid of the condensation, which delayed our departure. Do you guys normally run the fan at night with a window cracked open even when it is cold outside? I just hate to have to run the fan so that there is circulation, but then having to turn on the heat because people get cold inside the camper... and then not being able to hear nature. *sigh* I guess we all have to compromise? [?:~{]
     
  2. Grn Mtn

    Grn Mtn New Member

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    yes -we always have a window open for ventilation. Even with just two of us in the camper, we DO breathe all night long [LOL]

    Otherwise there is condensation on the ceiling and walls too if it's cold out. It was the same for all 3 PuPs.
     
  3. 01YZF6

    01YZF6 Dothan, AL

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    we opened the roof vents, and at least one window 1/4 way at each bunk end. with the fan on low, we had no condensation.
     
  4. Unstable_Tripod

    Unstable_Tripod Well, there's your problem!

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    You need cross ventilation to exhaust the moisture.
     
  5. Dammitjim

    Dammitjim New Member

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    So, there is no way around it, huh? I have to run some kind of fan hoping people won't get cold with the "wind" or I'll have to turn on the heater? Also, no hearing the sound of the outdoors, too?
     
  6. Unstable_Tripod

    Unstable_Tripod Well, there's your problem!

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    You have to let the moist air out somehow and there will be plenty of it with seven people inside. Most of us always leave a couple of windows open an inch or two regardless of whether we run a fan or heater. Adding either or both of those may also be necessary, depending on the ambient temperature and your personal comfort level.
     
  7. bikendan

    bikendan Active Member

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    we never have to run the fan. just have the roof vents open(we have vent covers) and a bunk end window corner open.
    but there's only two of us and our golden.

    camping at the beach, with all the humidity and using the furnace and a bunch of humans breathing out more most air, is like the Perfect Storm for condensation.
    you might just have to have a fan on low, to overcome all of that.
    we love our bathroom's Fantastic Fan for this type of situation.
     
  8. fmbhappycamper

    fmbhappycamper PuP Power

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    open a window, Dammitjim [:D]
     
  9. Dammitjim

    Dammitjim New Member

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    I did, I promise! I had the roof vents opened!
    I guess in our situation, at least I know the solution. I am going to try using reflectix next time over the bunk ends.
     
  10. kitphantom

    kitphantom Well-Known Member

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    Reflectix or PUGs over the bunk ends should help a lot. We really noticed the difference, esp. in the previous pup, in all cool temps, not just cold ones. [That pup was tiny, so the bunk sides and roof were closer to our bodies, so it seemed condensation appeared sooner than in the new one.]
     
  11. bikendan

    bikendan Active Member

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    Reflectix won't work as well as PUGs or the generic solar/sportsmen/all weather blankets, since you'll have to piece them together to get enough coverage and Reflectix is way more fragile than the blankets nor can you bungee them down.
    the PUGs will definitely help with condensation.
     
  12. Unstable_Tripod

    Unstable_Tripod Well, there's your problem!

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    Once you have PUGs mounted you can leave them there and just fold them up with the roof. I never took mine off when I had the Yuma. You can't do that with Reflectix because of the thickness. However, Reflectix works great for window inserts.
     
  13. BoomJammer

    BoomJammer Jason

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    Please help me understand this more. If ventilation is the solution to condensation, how does having PUGs help?
     
  14. kitphantom

    kitphantom Well-Known Member

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    PUGs do not reduce ventilation in any way. What they do, in addition to reducing heat buildup (very important for us in many of the high-altitude and sunny places we camp), it to create an air space between the roof of the bunk end (usually vinyl) and the PUG. The provides a bit of insulation, so there is not as much temperature differential between the bunk roof and the inside. Condensation occurs as the warm, moist air of breathing, existing, etc. hits the cold(er) roof. So they are a great addition to ventilation to reduce condensation.

    We use the bunk end liners in cold weather, in addition to the external covers. Last year, when the temperatures were in the teens at night, and the highs were in the twenties and thirties, with rain-turned-snow, we had a quick introduction in just how much difference the PUGs all made. I could actually feel the temperature differential between the liner and the tenting when I stuck my hand between the layers. After 4 nights, we did have some frost buildup between the layers in a few spots, esp. where the bedding mashed the BELs against the outside tenting. However, the reduced drafty feeling in the bunk, and the heat retention helped by the PUGs made it much easier to keep the pup comfortable when we were in it.
     
  15. Grn Mtn

    Grn Mtn New Member

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    It just adds a layer of insulation between the two temperature differences.

    Here's an example: when you cook a pot of stew, your kitchen windows get pretty steamy on a cold winter day. It's the combination of the window being cold on the outside and warm on the inside inside plus you are dumping a lot of extra humidity into the air. The longer you boil the soup, the more your windows will "sweat", because you are jacking up the humidity (putting more moisture in the air).

    In your camper the more insulation in the walls, the less contrast in temperature. You still might have to crack a window because you will be breathing and putting moisture into the air all night, but it should be better if it is insulated.
     
  16. Unstable_Tripod

    Unstable_Tripod Well, there's your problem!

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    You get condensation on the inside of the bunk canvas because the warm, moist air inside comes in contact with the cold surface of the tenting. With PUGs on top of the tenting the cold outside air is not in direct contact with the tenting so its inside surface stays warmer and therefore doesn't condense moisture as much. You still need ventilation in the trailer but with PUGs on the bunk ends you lessen the problem and therefore don't need as much remediation.
     
  17. Flyfisherman

    Flyfisherman New Member

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    Simply putting another layer of canvas over the top of the bunk end canvas will help - like one of those plastic tarps. I then added a sheet of Reflectix between the the canvas and that plastic tarp and that made night and day difference. That's where the idea of the Popup Gizzmos came from I'm sure; and no doubt they are even better then the plastic tarp and Reflectix.
     
  18. BoomJammer

    BoomJammer Jason

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    Thanks for all the replies. So, is condensation mostly an issue on the ceiling? ...or is it also likely to happen on the sides (bunk walls)?

    Regarding PUGS, do they have any insulation value themselves? Or is all of the insulating acheived by creating an air gap between the PUGs and the canvas/vinyl? Can I acheive something similar with the inexpensive silver tarps from Harbor Freight? I'm not sure how well these work as a radiant barrier; anybody know?

    We're going camping over Thanksgiving and the budget doesn't currently support buying PUGs before then, but we could swing a couple of tarps if they would help with the potential cold nights and with the condensation.
     
  19. Flyfisherman

    Flyfisherman New Member

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    The warmer the air the more water (vapor) it can hold ... call it moisture. When that warm, moist air comes into contact with a cooler surface the vapor (gas if you like) turns into a solid ... water ... because the cooled air cannot hold it Since the warm air rises to the roof that is where it cools first and transforms into those little rain drops on the canvas interior roof that fall on your head while your trying to sleep. Does not so in the main cabin because there's insulation between the cabin ceiling and the outside roof. Even covering with the simple plastic tarp will help to some degree. Sandwich some Reflectix in between and it works better yet. The good thing about the Reflectix is that it's flexible, fits easily and can be used over and over. Here's a pic of my '99 Starcraft with the bunk end covered with the plastic tarp and the Reflectix is underneath.

    [​IMG]
     
  20. Unstable_Tripod

    Unstable_Tripod Well, there's your problem!

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    It's not really about insulation. PUGs are like Reflectix in that they are both primarily thermal radiant barriers rather than insulators. I don't know the R-value for PUGs but a sheet of Reflectix only has an R-value of 1.1. Both work very well to hold heat in the PUP on cold days by blocking the long wave thermal radiation (heat) from getting out. It passes through the canvas, hits the reflector surface and is directed right back inside. Both keep the outside cold air from direct contact with the canvas (thus reducing condensation). So, thermal reflection rather than insulation is the active factor.

    A silver tarp alone will help some in that it keeps some of the cold air away from direct contact with the outside of the tenting (although it will transmit cold more than PUGs or Reflectix), but not nearly as much as Reflectix or PUGs because it isn't an effective radiant barrier like they are.

    Condensation can happen on the vertical walls because they are also exposed to warm, moist air inside and colder air outside. This is why many people put Reflectix inserts in their windows and why PUGs came out with interior bunk end liners.
     

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