Reddit mentions: The best roofing vents

This all depends on how much work you want to do, how you are with basic electrical connections and how much you want to spend up front vs how much you'd rather spend in electricity. Not that I've looked into this in any way.....

If you just hook up a standard gable fan like this it will run well enough and probably cool your shed a fair amount. You can also include a thermister like this which will give it a high and low threshold for operation. These can get pretty noisy though and if you leave it running all the time you'll probably see it on your bill.

For a bit more up front you can go with a full solar gable fan. Some models also allow connection to your 120v system so you can run them at night or during low sun conditions. These are great for situations like yours (or like my detached garage) where there isn't electrical yet or where you don't necessarily want to pay to have a fan run 10+ hours a day.

Vehicles run on the same output as solar panels (for the sake of this discussion) so you could easily cobble something together for less than $100 that would push as much air as one of those larger gable fans but also charge your cordless batteries, run low voltage lights, etc. You can also DIY a solar kit. I can get into the product details if you want, but overall you'd need:

• solar panel
  
• charge controller
  
• low voltage wiring
  
• speed/temp controller
  
• 12v DC fan like this one.
  
  If the fan is too noisy or moving too much air (in extreme cases, depressurization can be an issue) you can control fan speed with something like this and I'm sure there are 12v temp controllers as well.

https://www.amazon.com/Lippert-Components-389381-White-Siphon/dp/B01CZQ9Y6M/

That will create suction on the end of the hose if it's in the wind. Ideally, on the roof. I suppose you could try mounting it under the floor, reversed. No idea if that will help.

Otherwise you may have to do something to upgrade your fan situation. The tiny computer fan that's in there just can't compete with the other pressures. A 12 cm fan with higher capacity might be able to do the job but fitting it onto the hose would take some fabrication work.

You'll just have to keep your windows closed when you drive so the pressure in the van isn't dramatically lower than it is outside.

Other people have had this same issue when they have all their other ventilation closed, and turn their Maxxair or Fantastic fan to warp speed. The huge fan and all those cubic feet per minute of air just completely overwhelm the tiny little fan in the toilet and it doesn't have a prayer of keeping the air flowing the right way.

Not pictured, some weather stripping foam under the plywood in hopes of damping some vibration. Also I forgot to take pictures of wiring into the outlet in the crawl space.

The fan is a CX1500 "Cool Attic Power Gable Ventilator Fan"

The tools/materials I ended up needing:

• 1 10mm wrench
  
• 1 11mm wrench (Used for mounting the brackets)
  
• Drill
  
• Jigsaw
  
• Screws
  
• Hammer
  
• Nails
  
• Sealant (since its not an automatically closing one I sprayed some sealant on the wood to protect it)
  
• SOG Multi Tool
  
• The fan itself
  
• 24" square 3/8ths plywood (could have been a bit more in the vertical really)
  
• Wire to tie into the home power supply.
  
• Wire nuts.
  
• Weather stipping, self adhesive.
  
  I prepared the plywood first using the fan to draw a guide for the jigsaw. Drilled out a starter hole and followed the line with the saw. Also learned that I am bad at following lines.
  
  I had the 2x4 cut into 2' sections at Lowe's to save me some effort.
  
  Up in the crawl space/attic I nailed the 2x4 sections up, nothing special there and sprayed some sealant I had around. I also filled in some gaps in the gable vent (not pictured) with some foam backer rod I had extra of.
  
  Next went up the plywood with the cutout, I attached that with screws using the drill, much easier than swinging a hammer around up there. In hindsight, I should have picked up some longer screws and done the 2x4s with that too.
  
  Brought up the fan, mounted the brackets and mounted it to the plywood with screws. Had to bend it back a bit and adjust because there isn't a terribly large amount of clearance between the blades and the mounting bolts. If you buy one of these take note of that.
  
  I screwed the thermostat box to the brace in the path of the fan, wired in one end of the electrical cable following the instructions in the box - very straight forward. The load on the fan is fairly low, you can get away with 14-2.
  
  With everything else done, I killed the power and opened up the outlet up in the crawl space just across from the air conditioner blower. Didn't take any pictures of that, but basically just tied it into the black, white and ground wires from the house and closed up the outlet box. I removed the outlet to do it because I've never used it, nor have service techs. They just run an extension cord from in the house.
  
  Brought up the power and the fan worked. All in all if I take out the stop for breakfast, probably took me 2 hours. Hopefully it helps bring down the temps up there and make my summer bills a bit better.
  
  
  Edit - that thing I'm wearing in the picture is a Frogg Togg Chilly Dana, bandana. Really did help keep me cooler and acted as a sweatband.
  
  

I definitely recommend covers as well. I've had plenty of rainy stuffy days where I couldn't open a window and was glad to have vent covers. Raises your roof line a bit though(broke one on a tree once). Really easy to install a replacement if it happens. Only cost about $20 each and don't require any sealing, they hover just above the roof.

https://www.amazon.com/Camco-Cleaning-Aerodynamic-Included-40431/dp/B000BUQODG

Actually it is this video. (In my area, going through the side gable is not up to code.)

This was the kit I bought which made things easy. I wrapped the vent pipe in insulation which I bought at Home Depot.

I watched the video a few times then went to work. Pretty easy.

This is really nice looking.

I know you used treated wood, but it will get wet and swell with any moisture. I'd suggest pulling that axle and putting a really good enamel paint down on the underside.

Also, people are asking about cross venting for heat. Why not put a couple of these on the sides? http://www.amazon.com/Maurice-Franklin-Louver-2-5-Aluminum-Louver/dp/B00AFESMDS/?ie=UTF8&qid=1408463010&sr=8-6&keywords=eave+vent+covers

You could easily add a 12v solar cell just wire it directly to two 3" computer fans (one on either side). Have a couple lower ones on her side and then a couple upper ones in the back with the fans.

These would install quickly and not damage your aesthetic.

I bought a "cheap" setup on amazon for my greenhouse. ~$175 while the expensive units are about $300. Its not nearly powerful as i wanted but makes my plants dance so i continue to use them

ECO-WORTHY Solar Power Attic Gable Fan with 65-Watt 18-Volt Efficient Brushless DC Motor and 25-Watt 18V Solar Panel https://www.amazon.com/dp/B01MQRU3B1/ref=cm_sw_r_cp_apip_jF34WLG9u8hmY

Edit: something else i learned during my search, the roof mounted ones are for boats and RVs

Would this work for you?

Not to mention the amount of lint cleaning you have to do, it's a fire hazard, energy user and will wear out your dryer pretty fast. I hope you're using metal duct.

I have a similar issue where a periscope wouldn't work, but I used 4" flexible metal duct. I looped it up and over the gas line and then out the side wall.

Otherwise, is it possible to re-locate the vent hole?

Nice work. I did something similar with the same toolbox. If you run into overheating issues, you may find that another hole will help with airflow. I used these louvers.

Most are a standard size. You can safely buy one from Amazon...

Replacement vent

And this is what I put over my vent:

Vent cover

You don't have to worry about rain getting in, and theoretically, you can drive with the vent open.

Curious to see how much if any air from the hot exhaust migrates into the intake. Pink ribbon test held at various distances between the two holes when grills are/aren't attached? It looks like there is room to enlarge the intake hole higher and if there isn't any air migration, to the right. 100 degree intake might indicate some commingling so maybe not the right. Most of your big gains in performance may have already been made.

Another exhaust vent style.

Benzomatic TS8000 with the large camping propane tanks and if you really want to do it right, add a searzall.

Kenji's steak advice (Step 10A) is to use the torch WHILE finishing on your castiron - Which i find helps a LOT.

Have you been in the attic to see where its coming from?

Might be from a roof vent that is leaking. Most will last about the life of the roof but could have been damaged during install, squirrels, etc...
Very easy fix with something like these...

https://smile.amazon.com/Vent-Seal-Plus-Skirt/dp/B004LDYILO
https://smile.amazon.com/Oatey-Rain-Collar-No-Calk-Flashings/dp/B001AZ46O0
https://smile.amazon.com/PermaBoot-5531-3-Inch-Repair-Black/dp/B0047WL9SE



Take some pictures and post.

I did just that for a GPU rig, though it was fairly gerryrigged. My basic shopping list:

• Suncast BMS1250 Shed Tool Vertical, 22 cu. ft.
  
• Suncast Shelf for Suncast Shed Models BMS1250 and BMS2000
  
• Duraflo 620808 Gable Vent, 8-Inch X 8-Inch times 2
  
• Holmes Dual Blade Twin Window Fan, White
  
  Assemble the shed and install the shelf, cut two holes in the front doors at the shelf level for the gable vents and one big hole in the back at shelf level for the window fan, and install/wedge items in holes accordingly. Cutting the holes was a pain, I thought a Dremel would work well but it's slow and loud as hell so I ended up using a drywall saw that worked surprisingly well. I ran a cord for a power strip out the back under the fans.
  
  Mine sits at the back of a covered patio that's about 8-10 feet deep, so it's not directly exposed to rain or any significant elements. You might be able to make it work if you've got some overhang and you can put the back of the cabinet up close to a wall where water won't hit the fans too much. I also glued some dust filter material to the inside of the gable vents to help filter dust out, and I blow the setup out every now and then.

That's going to be rough. Will the HOA approve dryer vents on the front of the house? Similar to this here

I know you said NO vents, but it's a dryer vent... :)

It shouldn't since your p-traps should keep any gasses out of the RV from the grey tank.

I'd look for the anti-siphon valves. They're usually under a sink, they usually look like this.

You do know that vent covers are like $20 and would easily fix your problem?

You need something like this on the exterior.

https://www.amazon.com/dp/B001AH5J8A/ref=psdc_13397451_t3_B004Q0A5F0

I used this for a similar setup. Maybe it will work for you too

Dryer Vent Tite Fit, 90 Degree 18" to 30" https://www.amazon.com/dp/B000KKKGJ0/ref=cm_sw_r_cp_apap_iGQNfuudYJhBI

I like this one.

https://www.amazon.com/Quick-Vent-Safe-with-RFID/dp/B00P9QM9YA

Condensation happens when air comes in contact with something below the dew point. As long as your PC is above outside air (which it should be) you have no issues there. However bugs/pollution/snow/rain droplets. You could get a dryer exhaust duct and filter. The filter will stop most bugs and a U shape would hopefully prevent anything else from reaching your computer. As an added benefit you'll be able to have your computer further away from the window.

Everything I've read advises against pressure washing roofs. Only soft washes are ok. If it's energy savings you're looking for, I might suggest some more insulation in the attic, and one of those pink panther insulation covers for your attic stairs. That has done a lot for my home.

You can find enclosure exhaust ports with a hood on Amazon. Like this guy:

https://www.amazon.com/BUD-Industries-IPV-1116-IP32-Vent/dp/B00L3QU294/ref=mp_s_a_1_3?keywords=project+enclosure+vent&qid=1564685836&s=gateway&sr=8-3

http://i.imgur.com/1lJvL.jpg

Adjustable slide vent... I've been in those situation

Home depot; menards carry 3"-4" reducers

http://www.amazon.com/gp/aw/cr/B000KKKGJ0/ref=aw_d_crstars_miscellaneous

My only recommendation at this point would be to get some of these.

Just these ones https://www.amazon.com/dp/B016T42AIA/ref=cm_sw_r_cp_api_xsG2Ab1H0X116

Not OP, but:

torch

tank (can be had much cheaper at any home supply or hardware store)

Searzall