My Westy had a zip-out screen in the front pop-top window. (That was the only window in the pop-top on those models.) It was handy for accessing stuff stored in the roof rack.
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N8SRE
1990 E-250 Sportsmobile w/ penthouse top, converted when new by SMB Texas.
SMB West replaced my canvas in 2018. They told me at the time that zippers on the front three screens were now standard. Zippers in the rear two screens would never happen “for insurance reasons” (people falling out of bed on the middle of the night), though it would make installing the penthouse a lot easier for them.
I open my screens all the time in hot weather. Cross ventilation goes a long ways towards keeping the interior cool. Also, at least once I had to crawl over the hood and through the open front screen to get back in my van when my dog accidentally locked me out
I think I'd rarely open the screens on mine (as opposed to the windows, which I unzip all the time.) You may camp in places with fewer insects than I do. Being able to open them would be handy for maintenance, though.
BTW, out of curiosity, how much did the replacement cost you? Mine's still in pretty good shape but I know it'll come up eventually, if I own the van long enough.
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N8SRE
1990 E-250 Sportsmobile w/ penthouse top, converted when new by SMB Texas.
BTW, out of curiosity, how much did the replacement cost you?
$2400 for new canvas installed by SMB West (in 2018). Seemed like a lot at the time, but they wouldn’t sell me just the canvas, so doing it yourself is not an option, unless you want to repair and reuse the old canvas. In the end, I’m very glad I did it (as is often the case once the money has been spent and the enjoyment begins).