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Stopping door heat loss with curtain

  1. Dec 7, 2016 #1
    I got an original side door from 1922. Needless to say it's all warped and dented around the sides. My best attempts to weatherize have failed. It's extremely drafty. Various weather strips have not worked and the storm door helps very marginally. I was about to give up and just plastic wrap it leaving it unable for the winter, but I have one last idea however I'm not sure just how effective it will be.

    My idea would be to hang a heavy curtain over the door. From side wall to side wall. My question is kind of a general how to curtains actually provide insulation if they aren't air tight. The sides obviously aren't anywhere near tight with curtains so won't the cold air make it's way in eventually? Also what happens when I draw the curtain. Won't all that trapped air be released anyway?
  2. jcsd
  3. Dec 7, 2016 #2
    The weave of a cloth can trap air and it insulates a bit like a porous wetsuit. See the pyramidal weave of a traditional norwegian thermal underwear for example. Large tapestries were hung over exposed castle walls to keep halls warm.
  4. Dec 7, 2016 #3
    So once there is a cold layer trapped by the curtain/drape the drafts will end? If not, then it just kind of slows it a bit.
  5. Dec 7, 2016 #4


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    I don't want to be always this smart-ass who responds first ... (thanks, John101)

    Anyway, the insulation mainly depends on the air chamber you can create and maintain with the curtain. Thus the curtain's density might play a role: heavy curtains like the ones they use in theaters came to my mind. So your main goal should be to establish such an area where air isn't exchanged. All heat insulation I know of are based on trapped air, whether it is between to glasses of a window, or the air pockets in polystyrene.
  6. Dec 7, 2016 #5
    Don't know about stopping drafts as such. It basically works as an effective insulating screen that can follow contours and falls back in place when moved, ie 'self sealing'.

    edit add : anything can block air movement. the effect of the weave as insulator is in trapping air in the cloth.
    Last edited: Dec 7, 2016
  7. Dec 7, 2016 #6


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    Use a modern well fitted door on its own sub frame mounted to the wall on the inside of the old door .

    This uses the same idea as the double doors found in older top class hotels on the Continent for draught exclusion and soundproofing .

    The modern door can be very thin if you want it unobtrusive . Alternatively the whole assembly can be made removable for the summertime .
  8. Dec 7, 2016 #7
    How does the storm door fit into this? Maybe my storm is not sealed right?
  9. Dec 7, 2016 #8


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    Can you post a picture of the existing arrangement ??
  10. Dec 7, 2016 #9


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    Ha! I was about to buy a storm door, based on your last post, regarding "storm" doodads.

    Can you doodle a cross section of the door for us?
    As in, if you opened it, and looked at it edge on, what would the average thickness look like?

    Mine looks like this:


    The glass and thin wood panels are almost worthless as far insulation goes.
    I would describe them as "very good candidates for a heat exchanger".

    I solved the problem by installing window shrink insulation over both the window and wood panels.

    ps. I was going to buy a storm door for my other door, which was damaged last month, and has sprung some ventilation leaks.
  11. Dec 7, 2016 #10


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    Your instincts are correct: a curtain helps very little if the door isn't airtight.
    Well, since the door isn't airtight, there isn't any trapped air. That's the problem!
  12. Dec 7, 2016 #11
    Yeah, I think I'll just have to bite the bullet and plastic wrap the door and then buy a new one next fall.
  13. Dec 7, 2016 #12


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    I'm still not convinced you have air leaks.
    It may feel like it, but if your door is anything like mine, you may be feeling natural convective air current.

    Is it safe to assume that your storm door was professionally installed?
  14. Dec 7, 2016 #13
    Not sure, I was there when I bought the house
  15. Dec 7, 2016 #14
    The polar bears hair does not only trap air in between closely packed individual hairs, the hairs are hollow as well. Great insulation.

    A heavy thick tapestry like curtain covering the opening well is a very effective, let alone attractive, barrier. It makes no noise, falls back into place and if made of wool is relatively fireproof.

    - if you want to solve a problem, first see how nature and a lazy man does it
  16. Dec 8, 2016 #15


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    Air can come in from areas away from the door, travel to the door frame and enter the abode.

    Are you sure the draft is coming from a space between the door and frame, or from around the frame and molding?
    A storm door doesn't stop that kind of infiltration.
    Sealing the interior side of the frame could help.
    Or remove the interior molding, and stuff some fiberglass insulation in there, and tape the mating members.

    A heavy curtain will add an extra layer of resistance to air movement.
  17. Dec 8, 2016 #16


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    In the old house I put a heavy curtain over the door during a particularly heavy winter. Definitely helped. Doesn't mean it is the best course of action.

    If these doors are almost 100 years old perhaps they are worth preserving?
  18. Dec 8, 2016 #17

    jim hardy

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    I have an old metal door that always felt "drafty" in cold weather.
    Weatherstipping didnt help because the "draft" was just cold air flowing down it. It conducted so much heat out through itself that it was like having a refrigerator door open .

    So as to not to do anything irreversibly ugly i applied a layer of styrofoam from the lumberyard on inside with double sided tape .

    What a difference! You could feel from across the room that it was no longer a 'BTU black hole' sucking out the radiant warmth.

    But it was ugly.
    i was told, "That looks fine to an engineer but not to a housewife".
    An old quilt from local church's thrift shop fixed that problem .
    i mounted a cafe curtain rod at top of door, trimmed quilt to fit and Fair Anne sewed new edging around it. Clip-on curtain hangers hold it up just fine.
    Looks 'country' and the thermal difference is amazing.

    old jim
  19. Dec 9, 2016 #18
    The only way I ever got a curtain type solution to work was by using one of those thermal tarps (with the silver mylar on one side). That was many years ago and there was a tiny entryway where the cold air could be trapped. The other solutions listed above are more practical and long lasting, but the tap got me by until a more permanent solution could be put in place.
  20. Dec 9, 2016 #19
    That's what most people tell me, but it's so warped and beat up around the sides and edges that weatherstripping is extremely difficult to impossible.

    Another problem I can see is that even though the door is latched tight. There is no jiggle to the door when I pull the handle, the top right corner of the door I can push out like it's lose. I think that is the warping.
  21. Dec 9, 2016 #20


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    I'd worry for your sanity if your door giggled when you pulled on it, Greg. :-p
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