AC AIR CONDITIONING SUNROOF HACK

[Marusho]

I have a 2019 and am an AC victim. I do intend to steel myself before the warranty is up this fall and visit the dealer to start the process of getting the tsb done, but even if that works, there is another design flaw in the truck that needs addressing to ever be able to tolerate the hot interior. I have the panoramic sunroof and it is pretty close to my brain.

I did some temperature tests because I am a numbers guy. On August 5, 2021, at 2pm, with full sun on my WHITE Ram, and with a custom foil windshield shade having been installed all day and facing west, and an outside temperature of 89, I took these measurements before starting the AC: Inside sunroof 158, rest of roof inside 132, interior 111, dash 120.

My hack: I bought on Amazon for $20 a sheet of quarter-inch radiant barrier of a decent brand. It was 4x5 feet, but actually was generously cut to 48x67. I cut a piece 33x48 to place between the offending sunroof fabric and the glass (photos below). I retracted the sunroof halfway and slipped this in, then closed the sunroof shade. NOTE: You have to stop the closing manually before it touches the excess bit of foil hanging down, or, for safety reasons (OK, it's hardly a hazard) the shade recoils. You must have some foil extending out of the sunroof area to prevent the foil from possibly getting rolled up with the fabric. My measurements allow 5" of the 48" to protrude but you could use less, or just attach it so it cannot retract with the fabric.

The next day I returned to the truck at exactly the same time of day, again with full sun, but with an outside temperature of 92, to see if the foil had made a difference. Now the sunroof was a nice 129, while the rest of the roof was 131. The interior, sadly, was commensurately hotter, being 115 with a dash temperature of 123. But the important thing was that I had dropped the temperature of the offending sunroof by 29 degrees.

This is particularly important because without this correction the sunroof never really cools down and as I said, it's pretty close to your brain. With the foil installed it was possible to lower the temperature of the sunroof fabric to a safe 90 degrees after 20 minutes of AC. The rest of the roof dropped to 105-112.

While I don't claim that this little fix will make the inside temperature as pleasant as (any other brand), it is a help. The limitation for me will always be the terminal temperature of the vents, which is 54 for the center vents, 60 for the outer and 73 for the under-dash area. These sound like survivable numbers but the tropical heat of (most any state these days) will overpower this puny performance.

I detest sunroofs and always have. So why did I order a white truck with a sunroof? I haven't had a thin, roll-up sunroof cover before and didn't experience this greenhouse effect with the rigid sunroof shade in my 4Runner. And I like to leave the sunroof shade open in winter to heat the truck. Unless you really like the heat I'd think twice about this option. If you already made this tragic mistake, the foil is cheap enough.

Too bad you can't search on AC (too short) or AIR CONDITIONING (since you get air filters and leather conditioning), so I hope somebody finds this. . . .

 

[BigHerm611]

I had my roof tinted with ceramic tint, while not taking mumbers, it definitely makes the truck cooler. I can’t feel the heat coming through the roof like I could without it. My f150 I had before my Ram, was setup the same way. Pano roof with ceramic tint. The f150 was a black truck, and in Louisiana that truck would be ice cold in 5 minutes after sitting outside all day.


Sent from my iPhone using Tapatalk

 

[ais122]

FWIW, I hate summer and wanted to block out as much heat as physically possible so got ceramic tint on my driver/passenger side (35%) then 25% crystalline on the panoramic sunroof and during this heatwave in VA I keep my AC on 73 and its freezing in the truck (21 Laramie). The best and most fuel efficient way (according to the user manual) is putting the air on auto... not manually adjusting temperature. I keep my panoramic sunroof open 24/7 and feel zero heat, plus it's all 99% UV protection (i.e. my neck and arms don't get cooked anymore). Don't forget that on idle, the AC goes to fan mode, so if you're not getting cold air, it's because you're in park. I did hours of research on "AC problems" before I bought my truck and everyone complained about the cold air while they were idle in park, but now I know why lol.

 

[User_72751]

Don't forget that on idle, the AC goes to fan mode, so if you're not getting cold air, it's because you're in park.

Can you elaborate on this "fan Mode"??

 

[ais122]

Sure. This is for the "auto" mode only as I have never used the manual settings on my truck (just following the recommendations from the factory). Basically, once you set your cabin temp, the AC will adjust as the temperature in the cabin changes. Once the temperature is stabilized (you'll know you're at the right temperature because MDS will start working as you drive - MDS will only begin to work once your truck is at the optimum cabin temp -- again, this is when you're using the "auto" setting) the truck will, for fuel efficiency, engage in a fan mode where it'll only circulate in fan mode and not really blow out cool air. As soon as it warms up the slightest, AC will kick back on again. But the point I was making is that when you are in Park or at a red light, the engine will usually go to the "standby" mode where you really won't feel any AC... its as if your AC is only blowing lukewarm air (as if your AC is busted... but it's not). As soon as you start driving again, the AC will start again and you'll feel that cold breeze. You'll know exactly what I mean when it's like 78 degrees outside, you've been driving for about 20 min with the cabin set to 72, then you go through a long drive through for a burger. As you stop and go, you'll feel the AC and fan rotate. At the end of the day, I did pay a good bit for the tints bit what it did was cut out almost ALL the heat from the sun, which made it 10000x easier for the truck to regulate the internal temperature. My MPG went up, and my arms, legs, neck, and face aren't getting burnt to about absolute f'ing crisp. The factory tint is just cosmetic and doesn't provide UV protection, which I'm always concerned about, being in the truck for so long. With the size of the panoramic roof, I really suggest everyone get this done on their RAMs. But IMO you have to go with crystalline (not ceramic) for the sunroof, it's pricy (roughly $280 for just the sunroof) but 10000% worth. Hope that helps!

 

[ais122]

Oh also, FWIW, if you have a sunroof, no tint and you just keep that shade closed, you're still going to get cooked in the cabin. Put your hand up there when the sun is out and it's shockingly hot even with a 20% factory cosmetic tint. That panoramic sunroof is enormous.

Also, the crystalline is added IN ADDITION to the factory 20%, but you can still see outside and have that "open", non-claustropjobic feel. It's dark but not that dark.

 

[SpeedyV]

Sure. This is for the "auto" mode only as I have never used the manual settings on my truck (just following the recommendations from the factory). Basically, once you set your cabin temp, the AC will adjust as the temperature in the cabin changes. Once the temperature is stabilized (you'll know you're at the right temperature because MDS will start working as you drive - MDS will only begin to work once your truck is at the optimum cabin temp -- again, this is when you're using the "auto" setting) the truck will, for fuel efficiency, engage in a fan mode where it'll only circulate in fan mode and not really blow out cool air. As soon as it warms up the slightest, AC will kick back on again. But the point I was making is that when you are in Park or at a red light, the engine will usually go to the "standby" mode where you really won't feel any AC... its as if your AC is only blowing lukewarm air (as if your AC is busted... but it's not). As soon as you start driving again, the AC will start again and you'll feel that cold breeze. You'll know exactly what I mean when it's like 78 degrees outside, you've been driving for about 20 min with the cabin set to 72, then you go through a long drive through for a burger. As you stop and go, you'll feel the AC and fan rotate. At the end of the day, I did pay a good bit for the tints bit what it did was cut out almost ALL the heat from the sun, which made it 10000x easier for the truck to regulate the internal temperature. My MPG went up, and my arms, legs, neck, and face aren't getting burnt to about absolute f'ing crisp. The factory tint is just cosmetic and doesn't provide UV protection, which I'm always concerned about, being in the truck for so long. With the size of the panoramic roof, I really suggest everyone get this done on their RAMs. But IMO you have to go with crystalline (not ceramic) for the sunroof, it's pricy (roughly $280 for just the sunroof) but 10000% worth. Hope that helps!

The A/C never goes to “fan mode” (i .e. shutting off the compressor) when in Park and set to Auto. Never. But you are correct that when start/stop is engaged (not MDS), the compressor can’t run, as it is belt-driven. So temps can warm up a bit at a light (when in Drive with stop/start engaged).

It’s good to hear you’ve had a positive experience with having your sunroof tinted. There’s a lot of debate over whether this can lead to shattered sunroofs, but it seems like the right type of film applied by a knowledgeable installer is the most important factor.

I mostly keep my cover closed during the summer months in Texas, and the cover is never more than warm to the touch. I’ve documented my A/C performance in the past, and I guess mine seems to do fine. But I’d probably open my sunroof more if it was tinted like yours.

 

[ais122]

The A/C never goes to “fan mode” (i .e. shutting off the compressor) when in Park and set to Auto. Never. But you are correct that when start/stop is engaged (not MDS), the compressor can’t run, as it is belt-driven. So temps can warm up a bit at a light (when in Drive with stop/start engaged).

It’s good to hear you’ve had a positive experience with having your sunroof tinted. There’s a lot of debate over whether this can lead to shattered sunroofs, but it seems like the right type of film applied by a knowledgeable installer is the most important factor.

I mostly keep my cover closed during the summer months in Texas, and the cover is never more than warm to the touch. I’ve documented my A/C performance in the past, and I guess mine seems to do fine. But I’d probably open my sunroof more if it was tinted like yours.

Thanks for the clarification! You are definitely more knowledgeable than me on this issue, that's clear as day. I'm still working on trying to understand a lot of the complaints on the forums but I feel like just sitting down and reading the User's Manual will address a lot of concerns. My experiences will obviously differ with other owners, but hopefully it will give insight so people know that it's unrealistic to expect the AC unit to take a truck in 100+ degree temps to 65 (with factory tint) in one commute to the office or back home... especially if you keep the cover open.

I agree with you on the professional installation. They are professionals at what they do for a reason. You get what you pay for, as is usually the case?

 

[Nick57]

I'm not experiencing these issues with my AC. I keep my shade closed when I know it's going to be super hot out to help. I have my AC set @ 72 auto. My truck easily gets to a comfy temp in 2-5 min in park. Now I do crack open my windows a couple inches to let the hot air to escape. (it's an old trick but it works great!)