You are likely reading this post for one of two reasons:
- You are about to order a brand-new RV, and you’re curious whether it’s worth the extra ca$h to pay for double pane windows
- You own an older RV with fogged-up double pane windows, and you almost sh*t a brick when you were handed the repair quote.
So let’s talk about double pane RV windows: What do they do, what are their benefits, and most importantly – are they worth the money?
Also known as: Dual-pane windows, thermal windows, insulated windows.
Fair warning: This is one of those topics, like Donald Trump or Hawaiian pizza, that can split apart families and end bosom friendships. Be prepared for some controversy! But I, dear Reader, have the final answer (at the end of the article, of course).
Are RV Windows Single or Double Pane?
Since time immemorial, the standard RV window has been a single pane of glass. That was true in the 1930s, and it’s still true today.
However, in the past two decades, double pane windows have become much more popular. First debuted on luxury motorhomes, they have trickled down to 5th wheels, travel trailers, and almost everything in between.
But let’s be specific. There are two types of double-pane windows you’ll find in an RV:
- Glass. Dual pane glass RV windows, like the Lippert 8600 Series, look much the same as a regular RV window. You can buy them as fixed picture windows, vertical or horizontal sliders, or any combination thereof. Most are built with an aluminum frame and clamp ring, although you’ll see dual pane frameless windows on some ultra-luxury motorhomes.
- Acrylic. These plastic windows, affectionately known as “bubble windows,” are made of two laminated plastic sheets with an air gap between them. These are not available as sliders. Instead, the window is usually top-hinged and seals against a rubber gasket. Many people love acrylic RV windows because you can completely open the window (even when lightly raining) for full ventilation. You’ll see these referred to as “Dometic Seitz” or “Euro-style” windows.
Most criticisms or compliments apply to both manufacturing methods. At the end of the article, I’ll explain a few nuanced differences between glass or acrylic plastic dual pane windows.
(FYI, dual pane windows are NOT THE SAME as laminated windows. Laminated glass is used for windshields. It’s made of two panes of glass laminated together with a thin sheet of plastic in the middle. It stops the glass from cracking into large, dangerous shards upon impact.)
Why Do RV Manufacturers Use Double Pane Windows?
If you’ve ever lived in an apartment with single-pane windows, you know they aren’t much better than the goat-skin windows that preceded them. They’re loud. They drip or frost in the cold. They don’t stop the invasion of the summer heat.
In the 1940s and 1950s, engineers figured out that building a double pane window – a window with two panes of glass in a single sash separated by a dead air space – solved most of these problems. The air space acted as an insulator, keeping out both the hot, the cold, and the noise. Everyone loved it, and the construction industry has never looked back. In fact, today, you can buy argon-filled triple pane windows based on the same principles.
A few decades later, RV manufacturers got the same bright idea. Dual-pane windows started showing up in RVs, but the engineers hadn’t counted on one thing: vibration.
You see, the air space between the glass panes is supposed to be a “dead” air space. Nothing in or out. But if the gasket fails, then air (read: moisture) can sneak in. After a few vapor drive cycles, you start seeing condensation (fog) inside your window, where there’s nothing you can do about it.
So RVs quickly developed a reputation: Don’t put double pane windows in your RV, or they’ll fog up, and you’ll never fix it!
Thankfully, times are a’ changin’.
Who Makes Double Pane Motorhome Windows?
Manufacturers of RV double pane windows include:
- Peninsula Glass
Are Double Pane RV Windows Worth It?
Hmmm … this question means different things to different people.
Advantages of RV Double Pane Windows:
- Provides excellent thermal insulation
- More comfortable to sit next to
- Won’t sweat
- Cuts cost of heating and cooling
- Reduces noise levels
Disadvantages of RV Double Pane Windows
- Very expensive to purchase
- Expensive to repair or replace
- Limited lifespan
- Weigh more (except acrylic windows, which weigh less)
Will dual-pane thermal RV windows save you money?
Almost certainly not! You’ll almost never recuperate the upfront costs of double pane RV windows in energy savings. The only exception to this rule would be RV full-timers who frequently travel in severe weather conditions.
Will dual-pane thermal RV windows make you more comfortable?
Absolutely, yes! They work – no question. Sitting next to a single-pane window can feel like sitting in a solar reflector, but a double-pane window will reflect most of that heat.
So, if you’re trying to save money, no, double pane RV windows won’t save you money. Especially if you ever have to replace them!
… But if you’re looking for a more comfortable RVing experience, then yes, people swear by insulated windows. For full-timers, they’re a game changer.
Should I replace my RV windows with insulated units?
With that said, I wouldn’t recommend paying to upgrade all your single-pane windows to double-pane versions. That would be prohibitively expensive. Just buy or order an RV with dual-pane windows already installed. There are other ways to keep your RV warm in the winter or cold in the summer besides paying $2,000 for new windows!
How long will insulated dual-pane RV windows last?
You should know that windows will fail faster with shock and vibration. That means you can reasonably expect them to last longer on a motorhome, with a fully independent suspension, than on a travel trailer with primitive leaf springs.
Will Choosing Double Pane RV Windows Add weight?
A quick note on weight: Usually, switching from single-pane to dual-pane windows increases weight by 200-350 lbs on an RV. This will reduce your Cargo Carrying Capacity (CCC) by the same amount.
If you’re buying a Class A coach or a Toy Hauler of any type, the loss of 200 pounds capacity probably doesn’t matter. But if you’re buying a travel trailer, you need to do your research first. You might only have 1,200 lbs to start out with!
But again, this only applies to glass pane windows. Acrylic windows weigh less than single pane glass windows! However, they typically cost 2x-3x as much. And they’re usually only sold as top-hinged windows, not as fixed pictures or sliders.
How to Fix Fogged-Up RV Windows
Conventional wisdom says that “All double pane RV windows will eventually fog.” This was true in the 1990s, but manufacturing methods have improved since then.
There are plenty of RV owners with rigs older than 10 years without any fogging whatsoever. (Then again, there are also RVs that still get their double pane windows replaced under warranty within the first year …)
The more vibration an RV sustains, the quicker the window gasket will fail.
So you’re making a bet. If you lose the bet and have to repair a foggy window, what can you do?
Repairing Double Pane Glass RV Windows
WARNING! WARNING! The following advice applies to double-pane glass windows, not acrylic plastic windows.
The cheapest option is to drill two holes in your interior window pane (I’m not kidding) and let air flow through the air space. Put a dehumidifier inside your RV to accelerate the process. Maybe even pour some desiccant beads into the gap?
Obviously, this is a hack, and you’ll lose most of the benefits of a double pane window. But if you’re desperate, strapped for cash, and can’t even see out of the window, it does “fix” the problem.
Even if you’re outside of the warranty period, you might consider contacting your manufacturer. Some manufacturers, especially family-owned enterprises, might replace your windows if they believe it was due to poor workmanship.
If that fails (and it probably will), there are plenty of businesses that do a thriving business repairing failed insulated RV windows. You’ll pay $200 – $500 per window to have them removed, repaired (new gasket, cleaning), and reinstalled.
Some businesses will simply encourage you to replace the window instead of repairing it – especially if the price difference isn’t that big! You can replace the windows with replacement OEM double pane windows, or pay for a cheaper alternative like single-pane tempered glass or laminated glass. Neither of these options has the insulating benefits of double pane glass, but they’re far cheaper.
Repairing Double Pane Acrylic Plastic RV Windows
In my experience, glass windows are far more likely to fog up than acrylic windows. This is because glass windows rely on a mechanical gasket; acrylic window panes are either bonded or plastic-welded together.
If your acrylic RV window does fog up, there is no practical repair. You’ll need a new window. Contact your manufacturer or review your Owners Manual for more information. There’s a good chance the windows came from either Dometic or Lippert.
Some Science-y Notes on RV Double Pane Windows
I like the videos from Josh the RV Nerd from Haylett RV. Here’s his video on RV dual pane windows, which I’ve posted below.
Here’s what Josh says about RV windows:
“Tak everything you know about [house] windows and throw that crap out that window. It doesn’t apply. An RV isn’t a house!”
I do think Josh comes down a little hard on double pane RV windows, though. It’s true the increase in R-value is marginal. But a 50-100% improvement isn’t anything to sneeze at, especially when you’re camping in freezing weather! And many buyers prefer RV windows just for noise control, let alone the thermal insulation.
Here are some things you should know about RV double pane windows, especially if you come from a construction background:
- RV windows have awful R-values. Single-pane windows have an R-value of about 0.8 – that’s less than 1! Double-pane windows have an R-value of 1.3-2.0. (That’s assuming no drafts, of course).
- RV windows usually aren’t charged with inert glass, like argon or krypton. The dead air space is just that – air.
- In ye old times, no RV window had true e-coated thermopane glass. That’s changing, though. You’ll find e-coated glass on premium double pane windows, which improves heat reflectivity in summer.
What’s the Final Answer?
So, Reader, here’s the final answer:
Double pane RV windows won’t save you money. Spend $100 on window films and insulated covers rather than $2,000 on dual pane windows if you’re goal is to cut down on heating and cooling costs.
If you want comfort, then yes, double pane RV windows are worth the money. And the more windows you have, the more the upgrade is worth it! If you’re buying a 5er or motorhome, you’re already spending a retirement’s worth of money – why not make sure you’re comfortable while doing so?