Cap Vent Fan

yes sir!

 

Figured I'd update this thread with my cap fan V2.0. My original fan has been working flawlessly and does the job for the most part, but I wanted more. Let's face it, without A/C you want to move as much air as possible. For people with dogs and toppers, this is absolutely the way to go. Enough b/s, here's what it looks like so far:

$76 Ventline VP-543 12V Smoke Van Roof Air Vent , Brown

https://www.amazon.com/Ventline-VP-543-Smoke-Roof-Vent/dp/B00407CK5W

First thing I did was remove all the white plastic trim and paint that black. I didn't take any pics, but you can see from the product page they come white. Maybe that doesn't bother most of you.

Next step is straight forward, cut a big hole in the roof. I started the hole with a 1/2" drill bit, then cut the remainder with a jig saw. A standard wood blade seemed to work just fine, and I had to replace the blade once to make the full cut.



Mine was about 3/4" thick and almost looked like cardboard sandwiched between two hard layers.



After fine tuning the hole with a Dremel I cleaned up the surface and drilled pilot holes for the flange. One more cleaning, then ran a bead of RV sealant before finally screwing it down. Here it is in the up position.



Down



And the almost finished inside. I'm going to run power back to the rear and put a another switch in to control it from the rear as well as at the fan.



Here is the sealant I used:

$19 Geocel 28103 Pro Flex Black RV Flexible Sealant - 10 oz. (GC28103)

https://www.amazon.com/gp/product/B003VARIII/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

Only got about $80 in all of this and it really moved some air when I connected it to a spare battery. Install has been very easy.

 

I’m assuming it doesn’t, but would you say this keeps the shell anywhere near cool enough to keep dogs bag there in the middle of the day? I’m still having no luck finding a solution for my dogs on our trips to see family (+/- 3 hours) in the summer. A few weeks ago we made a trip and my only option was to literally take off the glass door. Even then, a thermometer I put back there stayed at around 90 degrees the whole trip. I don’t figure I can get it much cooler than that

 

I'll do a follow-up post after some testing. I've got a cheap weather station I can throw in there and monitor. It would be just as easy to have two of these for extreme conditions.

 

This isn’t about the fan, though it’s a really nice setup.

I do not have any fans and my windows are the sliders and not the hinged.


I do have two 70lb dogs.

We just got back from a 3.5k road trip through the southwest with temps in the 90’s during the day.

I bought two bags of ice each day.

One was a bag of solid ice. This I fixed on top of a water jug (for height) to let the air from the side window blow across it.

The second was a bag of loose ice chunks. This was mostly for their water bowl and then spread around the bed.

I climbed back there in 95’ temp and it was nice and cool. Dogs gladly jumped back in to avoid the heat.

 

How much current does it draw? Do you run it off your starter battery?

 

1.5 amps

 

1.5 amps is correct and yes I currently run everything off my stock starter battery. I know that’s not the best idea, but I want to replace it anyway with a larger capacity deep cycle so it won’t hurt my feelings when/if it goes. I keep a lithium jump starter in my truck so I shouldn’t get stranded.

 

Thanks! It's in my cart and on my list of things to do. 1.5 amps isn't much to ask of your vehicle battery. I wouldn't run it all day but 4-5 hours should be no issue at all.

 

I did some brief testing and came to the conclusion it decreased the temp about 50% relative to the outside temp, if I'm stating that correctly. 90-inside and 78-outside with no fans on in the full sun, fell to 84-in and 79-out, or about 5 degrees of the ~10 degrees delta. Bottom-line, it wouldn't be comfortable, but it's moving enough air to stay close to ambient temp, or tent camping equivalent, which is fine by me.

 

Appreciate the testing!

 

Neat thread.

I’ve been kickin around the idea of adding a vent to my shell. I looked at the thermometer I have in the shell the other day and it said 107*. Too hot for me

 

Being a boater and licensed Coast Guard Captain I frequently bring over ideas from the boating world. Check out the solar powered vents on the boating sites(westmarine.com). Built heavy duty to withstand the marine environment. I had a couple of these vents in my cruising sailboat. I installed on in my older Tacoma topper. Sorry, sold truck a couple of years ago - no pics.
Also recommend you checkout out how to bed something on fiberglass. You are going to have leaks eventually with that installation.

 

I have not had a single leak and believe me I've tried with a hose. I would be willing to bet that 98% of these types of vents are installed without bedding in fiberglass. Coming from a boating perspective maybe you have a point, but I'm looking at this from an RV perspective and those guys don't bed anything in fiberglass. The majority of these types of vents are installed with mastic tape and a self leveling caulk if needed. I opted to only use the caulk since I was working from a relatively flat and smooth mounting surface, and confirmed with the manufacturer I'm using their product appropriately.

The solar powered vents are a great idea, but they move about 1/10 of the air this one does. Drawing 1.5 amps is pretty insignificant, and I have a solar panel that will power it, no problem. I've ran the numbers and tested it in reality, and I can run both of my cap fans plus another fan inside the cap blowing on me all night with the stock battery. I've said it before, but I know this is not advised for the stock battery, but I have plans to swap it out for an Odyssey Group 35 AGM that will power everything for days and handle the recharges. If my power needs continue to grow, I'll consider a dual AGM battery setup and I know I'll be good to go.

 

I just decided to upgrade the window fan to this one:

$14 Thermaltake 200mm Pure 20 Series Black 200x30mm Thick Quiet High Airflow Case Fan with Anti-Vibration Mounting System Cooling CL-F015-PL20BL-A

https://www.amazon.com/gp/product/B00J0NZFIA/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Somehow it uses the same amount of current (0.2 amps) and moves double the amount of air as my previous purchase. This one is about 8" in diameter versus my old one which is 5.5". My original plan was to add another 5.5" fan, but this new fan accomplishes the same task and uses less energy so we'll give it a try first. For $17 I won't be out much. The new 8" fan is 3 decibels louder than the other one, which is likely not even noticeable by the human ear. I will say the roof vent fan I added is much noisier than these computer fans, but I popped in some cheap foam ear plugs and laid down for a bit and almost passed out last night, haha. I see some good nights of rest in my future back here.

For those interested, this is the fan I use inside the cap to have a little breeze blowing across me:

$35 RoadPro RPSC-857 12-Volt Tornado Truck Fan with Mounting Clip, Small 12v Cooling Fan, Black

https://www.amazon.com/RoadPro-RPSC...rnado+fan&qid=1561555012&s=electronics&sr=1-1

It was 79 degrees inside when I laid down last night, and with the three fans going it was quite pleasant. I had to turn the RoadPro fan inside the cap down to the lowest setting for maximum comfort.

 

When you installed that vent did you seal over the exposed honeycomb material? I know you said you laid down a bead under the vent on the outside but it's still going to absorb moisture from the atmosphere; in addition to the ambient humidity remember we give off a lot of moisture during respiration as well. If not, you might seriously consider pulling it and using some epoxy or fiberglass resin to fill it. There was a thread a while back with a fellow that put in a pipe vent style and I think he used plumber's epoxy putty maybe to seal it? I can't recall exactly and I can't find the thread right now.

That honeycomb panel is normally encapsulated in the fiberglass to keep it dry and it's a structural component to keep the roof shape and to give it some rigidity and keep it from flexing while in motion.

ETA: Found the thread in my saved threads. He used resin jelly. https://www.tacomaworld.com/threads/added-a-roof-vent-to-my-fiberglass-topper-shell.333187/

 

I had not thought of this and I'm glad you mentioned it. I'll definitely be making an adjustment. Thank you!