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Author Topic: Insulating windows  (Read 789 times)


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Insulating windows
« on: December 31, 2017, 07:21:56 AM »
So here in the northeast temps have been subzero.  In order to reduce heat loss I've bought rolled 1/4" reflective insulation and aluminum duct work tape and proceeded to insulate interior windows.  Now I'm wondering if the frost lines could travel back into the walls because they're not transmitting through the glass, but rather up against the insulate??  Any thoughts or recommendations would be greatly appreciated!!😉


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Re: Insulating windows
« Reply #1 on: December 31, 2017, 08:14:36 AM »
Any surface that is cold enough to reach the dew point will allow frost to form.  Keeping humidity low inside is your best hope.  Reduce cooking and showers to the bare minimum and allow some ventilation.


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Re: Insulating windows
« Reply #2 on: December 31, 2017, 08:32:09 AM »
   One of the things that exacerbate  the frost/sweat situation, is that most of our rv’s manufactured today have aluminum framing. Aluminum is a great thermal conductor. Causing sweat lines to form on interior if there is a great temperature differential between inside/outside. High humidity in the unit makes matters worse.

    Many folks also choose to run some form of propane fired heater to supplement the forced air system. The by product of combustion (any and all burning material) is water. So....additional water is introduced into the unit with this type of supplemental heat.
« Last Edit: December 31, 2017, 10:32:35 AM by Memtb »
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Gary RV_Wizard

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Re: Insulating windows
« Reply #3 on: December 31, 2017, 09:04:05 AM »
As I understand your concern, you are worried that placing the insulation on the glass may cause additional frost (excessive cold & moisture) problems in the wall. The answer is NO Worries.  You can't deflect coldness; heat either passes through something or not. The heat is inside the RV and trying to get out (radiate) through both walls and windows, and each material has some resistance to it. Insulation is simply a material with a higher than resistance to heat transfer.
Gary Brinck
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Re: Insulating windows
« Reply #4 on: January 01, 2018, 07:04:30 PM »
If it is freezing on one side of a wall and warm on the other side. The frost line is somewhere in between.

Here in nothing the you can do about that, some insulations come with vapour barriers others don't.

Vapor barrier on not the freeze point for ambient moisture is in the wall.  It is the way nature works.

« Last Edit: January 01, 2018, 07:07:21 PM by RGP »


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Re: Insulating windows
« Reply #5 on: January 01, 2018, 07:50:19 PM »
If you have the power, consider getting a dehumidifier. 


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Re: Insulating windows
« Reply #6 on: January 02, 2018, 11:37:24 PM »
We are living in our trailer full time and the canadian winter with -20 degree temps have already provided challenges.  We bought rolls of reflectix and we taped them to the windows and skylights.  We found that we could not get a good seal and the double windows were quite fosty and had lots of ice built up. Worried about the condensation, we decided to remove the reflectix and install a small 10" fan, attached to a cupboard door up by the ceiling.  Ths is on 24/7 and keeps the air moving and the windows beautifully clear.  We supplement furnace heat with  a Dyson Heater Fan and we are toasty warm.  I hang a Quilt over the door at night which also keeps the cold out and heat in.  Use the fan in the kitchen when cooking and i crack the kitchen window open a tad when washing dishes.  The bathroom fan is also open a slight crack to vent moisture...
« Last Edit: January 02, 2018, 11:40:53 PM by Armchair52 »

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Re: Insulating windows
« Reply #7 on: January 03, 2018, 12:26:59 PM »

[size=0px]>The bathroom fan is also open a slight crack to vent moisture...<[/size]

Yes, very practical. Water vapour is lighter than air and will rise through a slightly open roof vent first.
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Re: Insulating windows
« Reply #8 on: January 05, 2018, 12:29:16 PM »
If you're using a catalytic propane heater, they put a lot of moisture in the air. Get  a dehumififier and keep the moisture lower.
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  • Dan Nelson
Re: Insulating windows
« Reply #9 on: January 05, 2018, 02:18:10 PM »
I would strongly suggest getting rid of the catalytic heater.  Uses up oxygen you need to breathe. 
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