Background
On the first warm day of the season, we turned on the AC and it simply couldn't keep up. Something felt off, so I dug through our pile of manuals in the camper looking for the AC manual — but instead I stumbled on a Lippert Technical Service Bulletin regarding our windows:
I was sitting at the dinette table reading through it when I turned to look at the window on my right and saw the Lippert Certification Stamp staring right at me from the inside.
The TSB makes it clear: if the glass is installed reversed, you're losing somewhere around 20% or more in solar light rejection. And this isn't just one window — it's all 13 in the coach.
We submitted a warranty claim to Lippert. After reviewing photos of all 13 windows from both the inside and outside, Lippert responded:
On the surface, Lippert's initial response seems to align with our position: they state the "mirrored tint" belongs on the outside. But later in the thread, Lippert completely flips — now claiming the tint is applied to the interior. See the email ↓
Lippert claims the following:
- These windows are tinted, not coated.
- The coating is supposed to be on the interior surface of the glass, not the exterior.
We disagree with Lippert on both counts. We believe the following:
- Our windows are coated.
- The coating is supposed to be on the exterior surface.
Lippert makes the following statement about tint applied to the outside in the email thread below:
If, in fact, our windows had tint film, we would agree that this is true. But this just serves as additional evidence that our windows are coated. We have identified several campers with these windows — some installed correctly, some incorrectly. Some are at least a couple years old, and none are exhibiting any sign of bubbling, peeling, or deterioration.
Additionally, tint films have edges that can be picked and peeled off. And despite my best efforts, I have been unable to peel this "tint film" off my windows... if I had been able to do this, I would have ceded their point.
Lippert concluded the windows are installed "correctly" based largely on photos provided during the initial review. Their reasoning was that the windows appear more reflective in the exterior photos than the interior ones. We agree the photos present this way — but this is simply a function of ambient light differential, not coating orientation.
During the day, the bright light from the sun makes the glass look mirror-like from the outside while the dim interior side appears transparent. At night, the effect reverses: the glass becomes transparent from the outside (easy to see in) and mirror-like from the inside. The same glass, the same coating — the appearance flips entirely based on which side has more light. This means daytime photos alone cannot reliably identify which side the coating is on.
So, in an effort to prove this, we flipped one single pane of glass from its original orientation.
Lippert's assertion was made clear in the email thread below ↓:
If that is true, the flipped pane now has the mirrored appearance visible from the inside of our camper — and it should be identifiable from photos.
We challenged Lippert to identify the flipped panel using the photos below.
They could not.
If Lippert could not identify the intentionally incorrectly installed pane, then the claim that these windows are installed correctly cannot be satisfactorily substantiated — and a more thorough investigation is warranted.
To assist with re-evaluation, we've prepared this documentation site with all window photographs organized for easy reference. Each window set can be viewed individually by clicking its card below. Each image includes a download link to obtain the original full-resolution file.
