If you want to have your windows open when it's raining, use awning windows. I have awning window in the rear, and a slider on the side door, and water comes into the slider window during a rain.

 

ok thanks. I was just worried I'll forget about the awning and the slider destroys it.

 

I went with rear sliders for this reason from VWD 10" x 33" and real happy, good fit and no leaks. Purchased the awning "Broad Arrow" for the sliding door. Again real happy.
897-x-397-acrylic-dual-glazed-window-curved

 

I also have awning windows over our east/west bed. Larger slider on the door and behind driver seat. Very happy with the combination. Also, there is no issue with the slider hitting our curb side awning window when open. It easily clears it. The only time it might be an issue is if I mounted the snap on insulated window cover for the sliding door and the awning was fully open. I have had the awning open partially and the door with window cover cleared.

 

For the size, the awning windows give you 2x the ventilation of a slider. They can be opened all the way vs. at most 50% for a slider. And the rain hazard of a slider is a drawback.

It often rains a little overnight so it's nice to be able to leave the bunk windows open some without worrying about getting the bed wet with awning windows.

 

We used sliders on all of our windows in the last van build and they were ok but I think there are better options. We had the AMA slider bunk windows on both sides in the rear and AMA sliders on both the slider door and the driver side across from the slider. As I said, they were OK, but we opted for all awning windows on this build. Quality of the windows was one thing that wasn't great but that can vary. Amount of air for the size of window was also a big negative. Finally, the rain penetration was also annoying. I am sure there were other reasons I disliked them but those are enough reasons I would recommend awnings personally. The awning gives more air, there are shades and screens built into many of them, they protect from rain and also provide a little built in sun shade/awning too when they are open so it helps keep the interior a bit cooler.

We installed VanWindowsDirect TR201-AW/TL201-AW in the front area, and have 300x700 flat style arctic tern windows for the bunk area. The Broad Arrow windows also seemed like a good option but I hadn't heard of them until after I received the Arctic Tern. Not sure of their quality but just throwing it out for consideration.

The slider windows we had, got REALLY hard to slide open (could be an AMA thing) and finding a good lube took a few trials. I finally did find one but regardless of which one, they all run off and leave dirty drip trails where the water runoff is. The AMA windows also started losing their black finish.

 

All 3 of my added windows are Arctic Tern awning double panes with the new style that is less bubble like. Love them and so far zero issues. And they just released a very modest upgrade where I can replace the struts with one that let me set at any position vs. the 2 or 3 set ones. Parts are on the table to try out. But really like the company cares about their customers and continues to innovate. I've heard nothing but awful stories about CRL which their van windows seems like a niche side business they could care less about.

At steelhead fishing camp on Lake Superior and last night it got below freezing. Windshield a mess of condensation with the cover as unavoidable, but the arctic tern double panes were zero issues. That's worth a ton to me.

 

I put in CRL bunk windows. Awning on the driver side and slider on the passenger side. I did the latter for clearance with the sliding door. Turns out that with the CRL awning there is no clearance problem. I could've easily put awning bunk windows on both sides, and in hindsight wish I had.

I thought that having one slider would be a benefit in that I could leave it open while driving. In practice we never do that. It lets in too much dust (at least where we drive).

Regarding airflow, neither of the windows provides much airflow without the help of another force. Our MaxxFan is in the forward most position and even at the lowest setting (1 of 10), exhausting out, it pulls quite a bit of air thru the bunk windows. If it's hot at night we'll leave the MaxxFan on level one and both bunk windows open slightly. If it's cold the fan is off and both windows are still slightly open.

During the day, in warm weather, we leave both the sliding door and rear doors fully open (we have bug screens on both). In this case bunk windows are far too small to make any difference. If we're at a rest stop or truck stop the doors will be closed (for security), bunk windows open, CRL dual T-vent (behind driver's seat) open, and MaxxFan on whatever setting is needed to create significant airflow (rarely more than 5).

If I were doing it again I would do 2 bunk awnings and the dual t-vent behind the driver, and the fan in the forward most position. I would do more research on brands. All mine are CRL, and I haven't had any issues, but there are more choices now.

 

I put in CRL bunk windows

I considered those too but I wasn't a fan of how little they opened. How much does it actually open?

 

Lots of good recs in here. The one critical thing to consider on the passenger side is any potential interaction with the sliding door. Double check Firment based on window location and van length so that you don’t have an issue. It’s pretty common to do an awning on one side and a slider on the other. Outside of artic tern, most awning windows only open to 15 degrees so direct airflow is slightly restricted vs a slider. Precipitation is important as others have noted as well. Good luck!

 

We put in the VWD AW3310 bunk awning windows and are very pleased with them. They open about 3" out - I was concerned about door interference as they are pretty far forward, but no issues with clearance and the sliding door. Left one open the other night in the rain and no issues with water inside.

 

We opted for 2 of the VWD 3310 awning windows. We have one over the passenger side of the rear, E-W bed and the other over the galley behind the drivers seat. I liked the Arctic Tern windows better but wasn't sure they were in my ability range to install when we first started the build. The VWD awnings are really easy to install and we've had them open for several rainy nights with no problem. We also have a Maxxair fan over the bed and it does great to pull cool air up. The window build quality seems fine but nothing I'd rave about.