My XJ's black. As a result, it absorbs every ounce of solar heat present in Southern California. This is really annoying: I can have the A/C on at full blast but putting my hand against the headliner results in me touching fabric that's a good 30degF warmer than the interior. It also means that that heat is being conducted back into the cabin, which is not so good.
Here's an idea I had: my roof rack doesn't get used much - I think I've used it twice since I got my XJ. However, it provides a really good platform to put a thin sheet of aluminium on. This could shade most of the roof (I have the shorter roof rack, where the rails end at the b-pillar) as well as setting up cooling air flow in the shaded area, thus helping to lower the cabin temperature.
I admit that I've shamelessly stolen this idea from Land-Rovers, which have had it for years as the safari roof. And having been in ones that have this feature, it does work remarkably well. Of course, drivetrain heat would still penetrate the cabin, but even a 20degF overall reduction would be a big help, particularly if ambient temperatures are over the ton.
Obviously, this is going to introduce a number of concerns, mainly aerodynamic. And clearly, I wouldn't want the thing flying off at 70mph on the freeway. That would be really, really bad.
Does anyone have any ideas on how to do this in such a way that it wouldn't be a risk to damaging my XJ as well as other road users' vehicles? It'd be a major help to have this in the desert, so I'd like to start looking into the feasibility of doing it. I plan on asking a friend of mine who's an aeronautic engineer what he thinks about it tomorrow, but I'd really like to hear any input anyone else might have in the meantime.
Here's an idea I had: my roof rack doesn't get used much - I think I've used it twice since I got my XJ. However, it provides a really good platform to put a thin sheet of aluminium on. This could shade most of the roof (I have the shorter roof rack, where the rails end at the b-pillar) as well as setting up cooling air flow in the shaded area, thus helping to lower the cabin temperature.
I admit that I've shamelessly stolen this idea from Land-Rovers, which have had it for years as the safari roof. And having been in ones that have this feature, it does work remarkably well. Of course, drivetrain heat would still penetrate the cabin, but even a 20degF overall reduction would be a big help, particularly if ambient temperatures are over the ton.
Obviously, this is going to introduce a number of concerns, mainly aerodynamic. And clearly, I wouldn't want the thing flying off at 70mph on the freeway. That would be really, really bad.
Does anyone have any ideas on how to do this in such a way that it wouldn't be a risk to damaging my XJ as well as other road users' vehicles? It'd be a major help to have this in the desert, so I'd like to start looking into the feasibility of doing it. I plan on asking a friend of mine who's an aeronautic engineer what he thinks about it tomorrow, but I'd really like to hear any input anyone else might have in the meantime.
