You might know that the windows in a modern sticks and bricks home are what’s called ‘double-paned’.
Double-paned just means that two parallel pieces of glass make up the complete window. In between the two pieces of glass is a hollow gap, often filled with a special gas to increase insulation.
Windows are often the largest source of heat loss in an RV.
It’s only natural to think that by replacing all your single-paned windows in your rig with the double-paned kind, you’ll see an immediate and lasting improvement in insulation quality.
Related: Clever Mod for Cold Weather RV Window Insulation
But double-paned windows have a limitation that makes them impractical for use in RVs, and especially in travel trailers.
RVs Aren’t Built the Same as Stationary Houses – For Good Reason
RVs aren’t usually as well insulated as traditional stationary homes for a few reasons.
Firstly, many RVers use their rig during just a portion of each year – and usually in mild temperatures.
Secondly, RVs must be designed to meet certain weight limits. These weight limits impact the materials (and amount of them) used in their construction.
And lastly, RVs take a lot of abuse from the shock of long-distance travel on bumpy roads.
Even if you only drive your RV on newly paved stretches of road, the vibration from normal travel will over time damage your rig – especially the double-paned windows.
In addition, many travel trailers lack the high-quality springs and shocks of larger Class A motorhomes and experience a higher amount of vibration during travel.
How Double-Paned Windows Fog Up
Double-paned windows tend to fog up when subjected to strong vibrations. The vibrations cause the seals around the double panes to fail.
As a result, the gas between the two panes of glass heats up and escapes.
When the air in the inner space cools and contracts, high humidity air is drawn in, along with particulates that deposit on the interior glass surfaces.
The result: a clouded double-paned RV window.
A Couple of Personal Experiences
Here’s what user ‘seilerbird’ had to say on the RVForum about his experience with dual-paned windows in one of his rigs,
I had dual pane windows in one of my rigs and I will never have them again. The rig was only four years old and most of the dual panes were cloudy already. The vibrations of a motorhome breaks the seals between the two panes and it fogs up on the inside. There is no way to fix it other than have the windows professionally removed and cleaned and resealed, which costs almost as much as replacing the windows. Most 5ers don’t have dual panes because there is no springs and shocks in the suspension guaranteeing that they dual panes will fog up even sooner. If you install dual panes in your 5er be prepared to spend a lot of money repairing them.
If you’re going to spend time in either very hot or very cold climates at all, dual pane windows are a good feature to have. Ours are 14+ years old and the only sign of any condensation is the eyebrow pane over the passenger window. It’s not so noticeable that we would spend the money to replace it. Otherwise they have been trouble free. But I agree with the others, it’s not worth the money to convert form single pane, find a unit with double pane windows already installed.
Double-paned windows aren’t designed for use in high-vibration settings. The vibrations cause the seals around the double panes to fail, causing fogged windows.
Most travel trailers lack high-grade suspension systems that reduce vibrations. For this reason, travel trailers rarely come with double-paned windows.
Class A motorhomes and other large rigs often have a smoother ride. Many will have double-paned windows installed.
If your rig doesn’t come standard with double-paned windows, it may not be cost effective to switch them out. And if you have a travel trailer, you might want to stay away from double-paned windows altogether.
But don’t despair! You can make your own DIY insulating panels for a minimal cost.
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