Dear Dave,
How do the mosquitoes keep getting into the cabin of my RV? I tried sealing the chassis air filter, but it did not help. Could they be getting in the air conditioner or furnace ductwork? I can’t find any significant gaps anywhere. —Bill, 2016 Itasca Navion
Dear Bill,
The mosquito war has been raging for decades, and I would say even longer than there have been RVs! I doubt they are getting in through the roof air conditioner or furnace, as these should be completely sealed from outside air. The furnace has an intake vent that draws in outside air and passes through the burner assembly to exhaust fumes but never goes through the interior vents. These draw interior air by the blower fan, which then passes the air over the top of the burner, which heats the air and then blows it into the living area through the vents.
The roof air conditioner draws interior air through the air return, through the evaporator coils, and then back into the living area. It also draws outside air through the vents in the cover to help cool the hot refrigerant coils then exhaust that back outside. None of this air is supposed to enter the rig. However, if you have a gap in the evaporator covering it is possible mosquitoes could get inside. It would also mean your air conditioner is not running efficiently, as cool air would escape rather than all of it coming back into the rig.
Here is the front end of a Coleman model with the evaporator cover off. You would need to get on the roof, take off the external shroud, and look at the metal cover to see if there were any gaps and seal them up with HVAC tape.
Potential mosquito intrusion points
Your Navion has either one or two slides, depending on the floorplan. I would take a close look at the seal around these. Winnebago uses a two-sided bulb seal with a flap or squeegee in the middle, which is one of the best seals, in my opinion. However, there is seldom a 100% seal around the entire opening. Run the rooms out and look at the lower corners to see if there is daylight. Since a mosquito can crawl its way through a hole half the size of it’s body, it doesn’t take much of a gap. Also, check all your windows for gaps in the screens, as well as the door.
Try these popular deterrents
Wind
Mosquitoes are lightweight and any amount of wind will blow them around and hamper their ability to fly, so run a fan to keep them from your area. However, this most likely won’t keep them from coming inside.
Insect repellent
There are several good sprays that you could use on the seals around the slide rooms, screens, and doors. Some have DEET, while others are all natural.
Natural scents
Mosquitoes do not like citronella, peppermint, spearmint, and other mint scents. Some RVers have used lavender, catnip, cedar, and even garlic.
Smoke
A campfire with a little bit of smoke is a great deterrent if you like the smell of smoke lingering for a long time. Unfortunately, no matter where I sit around the campfire, the smoke follows me!
Use Thermacell
I ran into a product years ago that is one of the best mosquito deterrents I have found. Thermacell is available in a portable belt pack version for hiking, a lantern for around the campsite, or the Thermacell Patio Shield available on Amazon here.
The butane cartridge heats the pads and there is very little heat and no smell and works well.
Stay clear of water
Mosquitoes breed in water and wet areas, so find a spot for your RV away from lakes, ponds, rivers, and especially stagnant pools of water, if possible. The farther away, the fewer critters you will encounter.
Reduce carbon dioxide (CO2)
Our bodies give off CO2, and that attracts mosquitoes. Proper ventilation, as well as wearing proper clothing, will reduce the smell of CO2. Wash your face and arms periodically. An old school option is two teaspoons of vanilla extract with a cup of water in a spray bottle, which is almost as fun as a video game!
Camp in cooler weather
Mosquitoes are inactive in temperatures below 50 degrees. Maybe it’s not the most ideal camping conditions, but worth the note.
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Thank you, Dave!
After battling indoor mosquitoes for 3 summers, I finally discovered where they were getting in in my Winnebago Minnie Plus travel trailer… All of the crank out windows had almost imperceptible narrow gaps around the black window frames, where they were screwed into the surrounding frame. Not being handy, I just took strips of black electrical tape and applied them around each window. You can’t see the tape, and no more mosquitoes!
Check the wheel wells. On my Winnebago Micro Mini trailer, there was a gap where the wheel cover had pulled away.
I’d also check exhaust fans and the vent over the stove.
One other thing to think about with motorhomes is the dash HVAC. If that is left in the fresh air position that may be a possible entry point. It could even be a breeding ground for mosquitoes since it’s almost always got plenty of moisture ( perfect breeding ground) for mosquitoes. One mosquito laying hundreds on eggs in the HVAC ducts could cause an invasion. Close the door to the outside.
I don’t totally believe the stay clear of water answer. My permanent campsite is next to a swamp. I don’t have a lot of mosquitoes. Up where my mother lives there isn’t any bodies of water and her and my cousins property was inundated with mosquitoes. I use to have to spray her whole yard to try and get ride of them. Citronella candles don’t seem to work very well.
I have been using the Thermacell for several years. It even kept the mosquitoes and black flies away in the northern Maine woods this spring!