Reducing heat from sunroof

[Klonko]

Though my sunroof is tinted with UV-protection, the roof sunshade still gets warmer than the other parts of the roof. Any experiences if adding a 60-80% tinted foil to the sunroof reduces temperature?

[nigelforbes]

Tinted film is extremely unlikely to prevent heat transfer. We installed it on several windows in our home and it's not effective. Part of the problem is that unless the glass is insulated laterally from the steel, the heat will transfer from the steel roof to the glass and circumvent the film. That said, reflective film will reduce heat penetration by up to 80%, in theory but that doesn't take into consideration the bridging described above.

[Klonko]

Tint foils vary much as regards heat insulation. Our new car's foils are much better than the old car's foils. There is a rubber/plastic seal around the sunroof glass. The questions remains, does adding a UV-protective foil to a UV-protected glass reduce temperature significantly, or does the UV-protection of the glass depend on direct sun rays and not function properly anymore if the sun rays are already partially blocked by an UV-protective foil?

[KhunLA]

Roof rack/cargo holder, and some even look stylish.  Handy when out & about, I think.

[brianthainess]

Picture please. 

[Bandersnatch]

Just going to post a couple of screenshots from my blog as it saves a lot of typing.

 

[HauptmannUK]

Normal clear tempered automotive glass blocks at least 50% of UVA and UVB. Your sunroof is likely factory-treated to block much more than that.

If its heat transmission you're worried about then you need to block infra-red - IR.  There's numerous films on the market so best to visit an automotive window film fitter and discuss with them. Even if you block a lot of the IR the glass panel itself will still heat up and then act as a radiator to send heat down into the car. Many sunroof installations have an interior sliding panel under the glass to reduce this heat radiation.

Overall I don't think sunroofs are a good idea in tropical climates.

[Chongalulu]

On 10/14/2022 at 11:13 AM, HauptmannUK said:

Overall I don't think sunroofs are a good idea in tropical climates.

They’re not a good idea ,full stop! Why do you need another window when you already have 4 within a few inches?Adds unnecessary complication,expense and weight at the worst point (high up) and another thing to go wrong. Generally something that superficially adds attraction but generally gets little used in practical terms .

[Tropposurfer]

Unless you apply a thermal tint layer adding a standard tint won't do anything to stop the heat in fact it will add to it due to its darker shading absorbing more of the UV etc rays.  

Putting on roof racks and a silver or white panel/plate across the racks thus shading over the sunroof will fix the problem but that plate will also still radiate some heat downwards.

 

[Stevemercer]

2 hours ago, nchuckle said:

They’re not a good idea ,full stop! Why do you need another window when you already have 4 within a few inches?Adds unnecessary complication,expense and weight at the worst point (high up) and another thing to go wrong. Generally something that superficially adds attraction but generally gets little used in practical terms .

I agee

 

It's like building a balcony that gets full sun or having a roof sitting area. Seems like a good idea, but in practice never gets used.

[MrJ2U]

2 hours ago, nchuckle said:

They’re not a good idea ,full stop! Why do you need another window when you already have 4 within a few inches?Adds unnecessary complication,expense and weight at the worst point (high up) and another thing to go wrong. Generally something that superficially adds attraction but generally gets little used in practical terms .

Definitely.  And all that intense sun on the gaskets and you'll eventually have a leak during monsoon season. 

[Damrongsak]

I dislike sun roofs.  Leaky, complex, whatever.  I inherited a Lexus with a sunroof.  The damned thing opened itself in the night.  Fortunately is wasn't raining.  A friend has a Volvo SUV and it did the same, but it rained.  Lots of damage.

 

 

[rwill]

My Everest has a sunroof.  It has 2 panels the glass one and another solid one to block the glass one.  So you can let the light in or block it.  The glass also can slide open or tilt up to let air blow in.

 

In the 3 years I have had it I have never really used it at all.  Pretty much a waste except to 'show off' to people if your into that.

[bangkok19]

Only 2 cars I've owned in my life had a sunroof.

I've never ever used them!

The old Lexus had an internal sliding screen that completely blocked the sun which (I assumed) how they all should be.

My current Merc has a black screen that still allows about 3% of light through (when closed) which is a bit warm on my melon on a 35 degree day on a long trip.

I don't like sunroofs.  I don't like paying for something I never use.

I reckon, if you had the money to order a brand new luxury car..  you would probably have to pay MORE, not to have a sunroof. 

[steve187]

i have fitted some 5mm foil backed roof insulation to my mgzs sunroof, using 8 x 25mm suckers on each section, roof still opens with no problem and the heat coming through the sunroof is reduced, they are available on lazada, but always out of stock, so i made my own.

[paulbrow]

When I first got my company car which has a sunroof (If my car there would be no sunroof) I thought since I parked in covered, albeit outdoor parking, cracking the sunroof would be a good way to vent off excess heat. And that worked perfectly well, however I ultimately decided that the quantity of mosquitoes that found that little crack wasn't worth the heat released! I can't think of a single good reason to equip a car in Thailand with a sunroof! I apologize for ignoring to OP's actual question and will comment that I have not noticed excessive heat coming from the sunroof's interior cover panel.

[Klonko]

We have now installed a good quality 80% tinted foil on the tinted sunroof glass and it makes a noticeable difference, though the temperature beneath the sunroof is still warmer. Unfortunately, deselecting the sunroof as option was not possible.