the highest temperature ever measured in my motorhome was 140F. That was before I painted the roof white and installed my CPU fan powered vents. The highest temperature ever recorded since then has probably been around 106F.
I must admit I laugh at people that won't go to Walmart because everything is made in China. They go somewhere else and buy exactly the same product - still made in China but they pay more (and often peel the label off to prove it wasn't made in China). Long ago I learned not to hold others up to my standard of honesty as I was always disappointed. Today as I was checking out in Lowes, the checkout operator - a sweet young thing - totally missed scanning one item, putting it straight into my bag. Now, if I'd been dishonest, I'd have capitalized on that by paying and leaving the store. I'd not have been been able to shop there without blushing ever again and I'd have been as disreputable as Lowes. I pointed it out, much to her surprise and after she'd scanned it, paid my bill and walked away with a clean conscience. The item was only a couple of dollars but my conscience is worth far more!
The goal with my ventilation is to get the interior temperature of the bus to be the same as the exterior. It can never be lower without air conditioning which is something I won't be installing.
As Lowes didn't have any 3 inch sewer pipe, I scrounged around in the detritus in the back yard and found an 8 foot length. Various people have dumped stuff on the land from old card to dead microwaves. A good hunt usually turns up with usable materials.
Having returned with the booty from Lowes (hiss, spit), I set to work. In short order I'd cut and washed several sections of sewer pipe. The plan was to do as much with solid sewer pipe as possible but to use sections of my bilge hose to connect them to the pump. One piece I glued to the pump in the hope that it'll hold. The pump will be screwed to the ceiling. The back closet is after all just a closet with a useful emergency exit entry capability. It's not somewhere I'll be using on a regular basis now that my front door lock is operational.
The one fly in my ointment is that my plumbing cement had dried in the can. That wasn't helpful! If it were not for the heat and my wanting to get on with things, I'd have done what I usually do with useless junk. I'd have taken it out the back and shot it. Remember the DOA solar panel and the dead microwave plus numerous paint spray cans that refused to disgorge their content. I gather people do the same thing with useless politicians though I have yet to hear of anybody successfully ventilating the current pro Brexit British Prime Minister. One can only hope!
After cutting the sewer pipe in 90F and gluing various bits together, I ended up with a fairly solid looking system. I didn't actually finish what I was doing, however. Time escaped on me. The problem with working in heat is it slows me right down. Indeed, the thermometer on my charge controller read 41C when I was installing things. By the time I knocked off for the day, the ventilation system looked like this.
Given that I'm blowing air out of two mosquito mesh covered vents, it should be much more efficient than before. My sole concern is whether two self drilling screws is sufficient to hang my fan or whether aluminum rivets might be a better option.
Tomorrow I have to go back to work. The weekend is coming though! Two days and I can complete my ventilation system. This should be the last word in ventilation!