Roof vents are a key part of ventilation for nearly anyone who lives in a vehicle. Roof vents aren't required, but are very beneficial for most vehicles and living situations. Fortunately, they're not too difficult to add if your vehicle doesn't have them already. Smaller vehicles like cars and SUVs can get by with window vents or other solutions.
Features
More expensive fans have features that some will find worthwhile:
- thermostat to control fan
- more fan speeds
- rain detection and auto-close
- remote
Roof vent size
The industry standard for RV roof vents is 14"x14"[1] and can be as simple/inexpensive or fancy/expensive as one wants. See also #non-standard vents below.
Roof vent placement
There several and sometimes conflicting factors affecting vent placement:
- for effective cross-ventilation throughout the length of the van one would put the fan at the opposite end of the fresh air intake. For example, if the front windows were to be cracked for inlet then the exhaust fan could be placed at the rear. Front-mounted fans would provide cross-ventilation if there were a window or passive vent at the rear.
- for direct breeze at night the vent might be placed in the sleeping area.[2]
- for protection from rainfall at night (no cover, or manually operated fans), the fan might be placed away from the sleeping area
- for cooking exhaust the vent would be placed over the cooking area.
Some vans have flat (or nearly flat) areas to facilitate mounting fans.
- The mounting pad on a Sprinter near the front and also the mid/rear, dependent on body length.
- The Chevy Express has a mounting pad in the rear.[3] Older Chevys may have one, too.[4]
If no entirely flat spot is available, one can cut through the corrugations and either use an adapter to seal the gaps or build up the low areas with butyl tape, etc.
Those looking to maximize solar panel space may be able to mount low-rise vents under raised solar panels. In the summer, the airflow may help cool the solar panels which increases their power output. If the panel over the vent is large enough and the vent has a raised edge to keep water out, you may be able to have a vent with no external cover, which is instead closed on the inside.
If you have a van with solid rear doors, or a van with a lot of space above the door windows, there are wall-mounted vent fans available.
Installation
- Cut rounded corners rather than leaving right angles to prevent stress fractures in the corners. If you've already used a drill to make holes in the four corners you can leave a portion of the drill hole as a tiny radius.
- tape a bag around the perimeter inside the fan area to catch falling debris when drilling/cutting.
- Steel shavings that result from the cut must be removed since they will rust quickly.
Rain proofing
OEM vents are very simple and will let rain in if left open. There are several ways to deal with this issue:
Be diligent about closing the vents manually. Easier said than done, especially if you are away from your vehicle when rain begins.
Install a vent cover; this will allow for ventilation during bad weather. It also has a bonus function of decreasing sun and weather damage to the actual vent. Be sure your chosen vent is has enough room for complete movement of the vent's lid. Application notes:
- Fantastic recommends only their Ultra Breeze covers to prevent airflow restriction.[5]
- MaxxAir recommends their 95% flow FanMate cover for high powered fans.[6]
Select a vent with a rain-sensing function that will close the vent automatically, like the Fantastic Vent 807351. The manufacturer explains: "When dome (lid) is open and moisture contacts the sensor, the dome closes and turns fan blade motor off if it is running. When the rain sensor dries, dome reopens and fan blade motor runs if fan was running when dome closed."[7]
If the vent closes/opens on its own without rain the sensor may be dirty. It can be cleaned with a cloth and alcohol.[8] A malfunctioning thermostat can also cause unexpected opening.[9]
Select a vent with an integral cover, like the MaxxFan 0007000K.
Airflow direction
Since hot air rises, you may get best results in summer by using the fan to blow air out of the camper. If you have an air intake under your vehicle you may be able to pull in relatively cool air.
In winter you may want to run the vent on the lowest setting pulling air into the camper. This will preserve your warm air at the roof, contribute to circulation of air, and help control humidity.
Power consumption
Fans will use various levels of power at their different speed settings. For example, a 10-speed MaxxAir consumes between 0.1A at lowest speed to almost 3A at full speed[10]. The base 3-speed Fantastic model reportedly consumes 1A, 2A, and 3A respectively.[11]
Non-standard vents
Although 14x14" vents are standard in the camper world, there are other (usually smaller) options. The smaller vents often have greatly-reduced flow, as measured in CFM. Some of the smaller ones give cubic feet measurements, but are given for an hour. Example: 900 cubic ft/hour == only 15 CFM.
Mushroom vents
Mushroom vents are small mushroom-shaped vents which can be used as roof vents or, depending on the design, mounted on the walls or even under your vehicle living space for ventilation. Mushroom vents are typically mounted in 5" to 6.25" holes. They may be always-open or openable, powered or passive. Solar powered versions exist.
Wind-powered vents
Wind-powered vents, or Flettner-style vents, use cross-breezes (5-10mph+[12]) to spin the vent fan, pulling air through the vent. With no breeze, it acts as a passive vent. These are typically used as roof vents.
Roof vents gallery
See more in the Roof vents category. For image credits, open image and click More Details.
Resources
| Search Amazon | Search Amazon for related products. | |
| Search forums and groups | Search van life discussion groups for "roof vents" | |
| Search related sites | Search van life sites for "roof vents" | |
| Search NomadLife.wiki | Search other pages on this wiki for "roof vents" |
Some or all of the content on this page was originally sourced from this page on RVWiki
- ↑ http://www.arizonarvpartscenter.com/standard-14-x-14-rv-vent-lids-s/468.htm
- ↑ Or one might just use a portable fan for this.
- ↑ https://www.sportsmobileforum.com/forums/f24/installing-roof-fan-in-ford-e350-2725-2.html#post41985
- ↑ https://www.fordtransitusaforum.com/threads/location-for-maxxair-fan.25209/post-322786
- ↑ http://www.fantasticvent.com/fan-tastic-vent-s-faq.html
- ↑ http://www.airxcel.com/maxxair/products/covers/maxxair-2
- ↑ http://rv52.com/wp-content/uploads/2012/05/Fantastic-Vent-RV-Vent-Users-Manual-Operating-Instructions-model_6600.pdf
- ↑ http://www.fantasticvent.com/fan-tastic-vent-s-faq.html
- ↑ http://www.irv2.com/forums/f258/fantastic-vent-fan-168102.html
- ↑ https://i.redd.it/ii18f5vmm9l01.jpg
- ↑ https://www.cheaprvliving.com/forums/showthread.php?tid=24153&pid=296762#pid296762
- ↑ https://www.flettner.co.uk/flettner-frequently-asked-questions/
