Hmmmm....I have the "low profile" A/C units and shrouds on our rig and there are NO louvers cut in the covers at all and the A/C's seem to run fine. I'm assuming the designers had some idea of what they were doing and I like the lower profile.
That said, and expanding on prichardson's comment, for this mod, the problem that comes to my mind is that the back of the A/C shroud is most likely a "low pressure" area when the rig is travelling. Ever wonder why the back of your car, rig, van or SUV tends to get dirtier than the rest of it? When travelling forward, the back is a low pressure area that draws in road dirt, water, exhaust, etc. and deposits it on the surface. Even when you see vehicles travelling down the road in the rain, the low pressure area behind it tends to atomize the road spray, giving that "cloud of mist" right behind the vehicle reducing your visibility. One reason why it's nice sitting up high in the Class A...you see right over that. :) But I digress...
My concern for this mod would be that when travelling and the roof A/C units AREN'T being used, will that mesh screen he made, with the smaller holes, tend to become plugged up quickly with deposited material? I realize that with the original louvers, some of that stuff made it through to the condenser, which is why it needs to be cleaned periodically. But about half of it was left on the structure of the louvers. That structure is now removed. With this mod, I'm guessing the condenser will stay cleaner, but that grill might need to be cleaned more frequently as it's now the first line of defense against the debris sucked in by the low pressure area.
When the A/C is running, this probably won't be as much of an issue because the fan will be forcing debris out the grill.
On a lesser, more technical note, I also am not 100% his anemometer readings can be completely trusted. With the original louvers, a large part of the anemometer sensor was over a louver, not a slot. A truly accurate test, in my opinion, would have to include the airflow through the entire louver structure in a "wind tunnel" sort of set up. I'm not saying this doesn't improve air flow. It might. On the other hand, I also know that fans draw air through a screen much more efficiently than blowing air through a screen, and what he installed there is borderline to being considered a screen. Again, I'd like to see the airflow numbers on a full mock-up, not just a single reading on a selected part of the screen. I'm sure for BOTH systems, you do not get constant numbers as you move the anemometer around the path of the airflow. Such being the case, it's pretty easy to make the result LOOK much better than they actually ARE.
Actually, now that I think about it more, the aerodynamics and flow rates might change quite a bit while the rig is in motion due to the low pressure area created. In my mind, that casts even more of a doubt about the accuracy of the airflow numbers presented. Obviously this isn't an issue when parked, but at highway speeds, there might be some drastic differences in the airflow numbers.
Anyway, take all of this commentary for what you will. It's just my $0.02 worth. I'm not sold that it actually would be an improvement, and might be a detriment. As I said, my A/C covers have no louvers and I'll stick with that. :)
~Rick
