THE SCIENCE OF KEEPING COOL: UNDERSTANDING RV VENTILATION
9/6/2024
by Thomas Godwin
A stagnant, stuffy environment with poor RV ventilation is no way to live. On hot summer days, it can reach unbearable levels. Add in the family dog releasing air from both ends, or the aftershocks of a trip to Taco Bell, and suddenly, piling out of the RV to sleep in the rain sounds like an enticing option.
Cool is comfortable and clean, fresh air even more so. Some RVers get a little unlucky in this regard, with vents that are small or otherwise underwhelming in operation. It can be challenging, especially if you’re in the southwest or the southeast in the middle of July.
A properly ventilated RV improves your attitude and comfort. It’s also good for you mentally and physically. Fortunately, we won’t leave you hanging in that dead, stagnant air. This little write-up will cover the basics, along with types of vent systems, maintenance, troubleshooting, and optimization. If you want to avoid a blanket party without the blankets, stick around and read on!
BASICS OF RV VENTILATION SYSTEMS
No, it’s not an RV in this example, but the concepts are the same!
RV ventilation happens on a micro scale compared to ventilation in a traditional home. Big Class A motorhomes mitigate this somewhat, but the point remains the same. Changes happen faster, and when your RV’s ventilation is poor, it will not go unnoticed for a long time.
In a nutshell, heat rises, and RV vents allow that warm air to circulate up and out. There are manual vents and automatic vents, but the only change is in how they operate and how well they operate. Some come with a fan to expedite the process, and some do not.
NATURAL VENTILATION
An unpowered RV ventilation system is as much about what you do to create airflow in your RV as it is about what the RV offers to accommodate it. You’ve probably experienced natural airflow currents before. When you leave a window or a door open in a building, you’ll notice that other doors inside the building slam shut.
Opening the vent in your RV roof is not enough on its own. Opening a window along with the vent, however, is like closing the circuit in an electrical system. You effectively create a pathway for air to travel, pushing the hot air up and out through the vent.
Windows, roof vents, doors, or anything else that exposes the interior to the exterior are natural ventilation points.
MECHANICAL VENTILATION
As you can imagine, mechanical ventilation is, well, mechanical. There are all kinds of mechanical RV ventilation systems out there, and every brand will tell you theirs is the best.
The benefit of having a fan is that it hastens the process of circulation, pulling the hot air out and letting the cooler air in. After all, a more comfortable living environment is the goal.
Natural ventilation systems are better for boondockers and those who like to go off the grid for a while since they require less power. When you have plenty of juice or prefer shore power, however, it’s hard to beat the optimized airflow of a mechanical system.
Air conditioners, roof vents, swamp coolers (evaporative coolers), or whatever you can throw together with some ice, PVC pipe, portable fans, and a Styrofoam cooler are all forms of mechanized ventilation. Throw in exhaust fans and intake vents, and that just about covers all of them.
A regular old box fan sitting in the doorway counts as well, so feel free. RV ventilation is not a singular effort, so get creative!
The technology is all over the place. There are vent fans with rain sensors, as mentioned above, and remote controls to activate them. There are even vent fans you can tie into a smart home system and operate with your lovely voice. It’s always fun telling Alexa what to do.
Whatever your persuasion, there’s something on the market to accommodate you. If you want to get downright bougie with it, what are you waiting for?
HOW RV VENTILATION SYSTEMS WORK
The process of RV ventilation is relatively cut and dry. A lot of it revolves around air pressure. Air pressure actually has a preference, and that preference is to remain the same, no matter where it’s at. When all of your doors and windows are closed, the air pressure in your RV is usually lower than the air pressure outside.
PRINCIPLES OF AIRFLOW
When you open a door, the air rushes in to equalize the interior and exterior. This inflow process is amplified if you have an outflow (vent or another open egress point). These pressure changes are why your interior doors in a residential home have a tendency to slam shut when you open an exterior door.
A powered or mechanical roof vent is both an inflow and outflow—like two open doors or windows. This is true even when all of your windows and doors are shut and the fan is running. There is no such thing as a completely sealed RV with zero inflow whatsoever. If that were the case, RVs would become suffocation chambers, and they probably wouldn’t sell as well 😂.
Of course, hot air rises and cool air settles, explaining the world’s most baffling mystery—why hot air balloons travel up. We’re kidding. When inflow and outflow are rolling right along, that hot air is expelled through your vents, allowing the cool air to fill the room. The better your transfer efficiency with your RV ventilation, the faster and more effective your cooling system will be.
ROLE OF INSULATION
Heat doesn’t just come in through an open window or door. Heat transference occurs through other materials, such as your RV’s walls and windows. This energy is a “radiating” energy type, not to be confused with radiation. A nuclear RV is not a thing…yet.
Insulation reduces this heat transference and subsequent heat-radiating effect within the RV. In the process, it improves airflow by reducing the amount of heat the vent has to transfer from within to without.
OPTIMIZING VENTILATION FOR MAXIMUM COOLING EFFICIENCY
Now, every RV comes with some level of inflow and outflow efficiency, even if it’s just in the form of windows. The key to comfortable living is figuring out ways to optimize it.
NATURAL VENTILATION STRATEGIES
Let’s say you have a natural roof vent with no power or fan. What do you think is the better option: opening a window in the same room as the vent or opening a window/door as far away from the vent as possible? The answer is the latter. Of course, you can open all of your windows, but that wouldn’t necessarily be the solution you think it is.
The more windows that are open, the better able the outside air is to equalize pressure with the inside air. A window or two on the opposite side of the RV, away from the vent, will help create better airflow. Think of it in terms of a wind tunnel. You have to have the tunnel to create one. Remove the tunnel, and the air pressure equalizes, settling down.
Alone, a vent may not be enough in terms of outflow. You may need to open another window on the other side of the RV to create a more effective cross breeze.
MECHANICAL VENTILATION STRATEGIES
Unfortunately, mechanical ventilation systems won’t take away all of the work. There are still ways to maximize it. Besides, if you’re in South Florida in July or August, you’ll want to do everything possible to maximize airflow and cooling.
First and foremost, you need the right roof fan, which is indeed one of those instances where you get what you pay for. The Maxxair MAXXFAN Deluxe generally gets a lot of hype, but Maxxair also gets a lot of criticism. Be sure to do your research before you dive into a purchase.
Use your exhaust fans to help remove hot air and reduce the strain on your RV ventilation system as a whole. They’re there for a reason, and even if you have a really small one, some pull is better than nothing at all. This is especially true if working in conjunction with other outflow options.
If the weather is particularly nasty and opening the door or windows is not an option, portable fans are worth their weight in gold, especially if you already sleep with one. Fortunately, these things come in all shapes and sizes. There’s everything from a warehouse fan down to a portable, battery-powered fan-mist device.
Some of the smaller fans that plug into USB ports put out a surprising amount of air, especially for something like a little reading nook. You can run one for nearly an entire day on nothing more than a 30,000 mAh portable charger.
INSULATION AND SEALING
You probably read the term “preventative maintenance” quite often here at Do It Yourself RV. The importance of preventative maintenance cannot be overstated.
In the summer, install reflective film on your windows to minimize heat transference and give your insulation a well-deserved break. Thermal curtains and blinds are also good ideas. Weatherstripping, an RV vent cover, and fans minimize what the insulation can’t take care of.
Window shades and awnings are always helpful, and remember to park in the shade throughout the summer months and in sunlight throughout the winter months.
Establish an inside and outside routine, checking your walls and exterior for cracks, leaks, or any broken seals. These can develop into serious issues, especially if water from the rain or moisture from the air has unfettered access to your insulation. If you find them, seal them. Don’t wait around to do it some other time.
MAINTENANCE TIPS FOR VENTILATION SYSTEMS
Again, with preventative maintenance. It never gets old! Maintenance is vital to keep that airflow going, even if you have a simpler, natural RV ventilation system. You don’t have to tackle these things each and every day. If that were the case, no one would bother owning an RV for all the extra work.
However, you need to establish a general routine for cleaning your vent system. It’s better to just make a day of it—covering your vent system and performing a full inside-out inspection as well. Most RV vents are generally accessible, and you can use an air compression can to blow off the blades.
Clean and wipe everything else down, avoiding dust buildup whenever possible. While you’re cleaning, check everything over for any signs of damage or signs that something needs to be replaced soon.
You don’t have to do much to adjust your ventilation system from summer to fall to winter, but you will have to make adjustments to the things you do to assist it. You obviously don’t want a highly efficient inflow and outflow in the middle of a north Minnesota or Alaska winter.
TROUBLESHOOTING COMMON VENTILATION PROBLEMS
Nothing good lasts forever, and eventually, things will wear down over time. No matter how well you clean a mechanical fan, there’s no such thing as an infinite motor. Some things happen due to negligence or faulty craftsmanship, and others due to time.
POOR AIRFLOW
RVs are infamous for not having highly efficient airflow systems right off the buyer’s lot. Nevertheless, the first thing you need to do is look for blockages. If you create a cross breeze flow with one side of the RV to the vent, the vent may not be enough.
Sometimes, this means upgrading your RV ventilation system to a mechanical system from a natural or a better mechanical variation with more pulling power. Adding additional vents is helpful as well. Consider adding RV vent covers. Many RVers say that simply adding a vent cover makes a huge difference.
For humid climates, dehumidifiers are the way to go. Unfortunately, the moment you open a door or a window will undo everything the dehumidifier does. It’s best to use the dehumidifier at night when you’re sleeping. Humid air is much more irritating when you breathe it in as you sleep.
Portable fans combined with dehumidifiers help dry the air as well. Just be careful at night. If you leave a portable fan blowing directly on you, you might wake up feeling like you breathed in the entire Sahara Desert.
CONCLUSION
RV ventilation systems are far more important than you realize, especially when dealing with the cold and hot extremes of the seasons. They work even better if you can stay on the move, traveling to locations that are best, depending on the time of the year. Head to southern states in the winter and northern states in the summer.
Preventative maintenance is key; even if you are planning on upgrading, you need to make the best of what you have until you reach that point. Speaking of points, the point is to have the most relaxing and comfortable time in your RV. An efficient RV ventilation system will help with that.
Living and/or camping in an RV is supposed to be fun and relaxing, not moments of being reduced to a puddle of sweat on the floor or an ice cube in the corner. Upgrade or improve your RV vent system and enjoy the R&R. You’ve earned it!
If you would like to reserve a stay with us and enjoy the Williamston, Greenville, Washington and Eastern NC area please give us a call 252-943-1699 or visit our website: Treeside RV Park
To reserve a spot, give us a call 252-943-1699