Why We Finally Bought an RV Dehumidifier After Our Florida Disaster
We pulled the mattress off the platform in our bedroom one morning in June and found black spots spreading across the wood underneath. The smell hit us before we even saw it — that musty, damp odor that means you have already lost the fight.
We had been parked in central Florida for two months. Humid, sure, but we run the AC. We crack the vents. We thought we were fine.
We were not fine. The mold had spread under the mattress, along the platform edges, and into the corner where the wall meets the floor. We spent three days scrubbing it with vinegar and bleach, pulled out the mattress to air it in the sun, and ran two fans nonstop to dry everything out. The whole time, we kept asking ourselves how we missed it.
Here is what we missed: two people and a dog living in a sealed box put out more than half a gallon of water vapor into the air every single day by breathing and sweating. Add in showers, cooking, and the refrigerator running, and you are pushing close to a gallon of moisture into your RV daily. In a house, that moisture escapes through walls, attics, and leaky windows. In an RV, it condenses on cold surfaces — windows, walls, and anything pressed against the floor.
We thought running the AC would handle it. Air conditioning does pull some moisture out, but only when it is running. At night, when the temperature drops and the AC cycles off, the humidity spikes. That is when condensation forms under mattresses, behind cabinets, and inside storage compartments. By morning, everything feels dry again, so you never notice the problem building.
The mattress platform was the worst spot because we had no airflow under there. Condensation formed every night, the wood stayed damp, and mold moved in. We have since learned that even with a dehumidifier running, you need ventilation under the mattress — we now use a polymer mat that lifts the mattress off the platform and lets air circulate. Without that, no dehumidifier in the world will stop condensation in a dead air space.
The mold cleanup cost us about two hundred dollars in cleaning supplies, a new mattress cover, and a lot of scrubbing. The RV dehumidifier we bought after that cost less than the cleanup. We should have bought it two months earlier.
The Two RV Dehumidifier Models That Actually Saved Our RV
We run an Ivation 13-pint desiccant unit when we are plugged into shore power. It sits on the floor near the bedroom, drains continuously into the gray tank through a hose we rigged up, and we set it to maintain 45 percent humidity. The first week we ran it in Virginia during a cold snap, we could not believe how much water came out — easily two gallons a day. The unit puts out a little heat, which actually helps in winter, and it runs almost silent. We have left it on for three straight months during a humid summer stay in Florida, and it never froze up or quit.
When we are boondocking without hookups, we use a 12-volt unit that pulls maybe a pint a day. It is not enough to handle serious humidity, but it keeps the worst condensation off the windows and stops that clammy feeling you get in the morning. We empty the tank every other day. It works for short trips, but if we are dry camping for more than a week in humid weather, we accept that we are going to deal with some moisture.
We tested five other models over two years. A cheap compressor unit from Amazon froze up every time the temperature dropped below fifty degrees and quit working entirely. A household dehumidifier we tried ran loud enough to wake us up at night and vibrated so much we thought something was broken. Two other 12-volt units died within six months. Skip them.
Why 12V and Electric RV Dehumidifier Options Aren’t Really Competitors
People ask us all the time which one is better, and the question does not make sense. They solve completely different problems.
A plug-in electric dehumidifier for RV use pulls serious moisture out of the air when you are parked with hookups. It runs all day, drains continuously, and actually keeps your rig dry. A 12-volt unit sips power and pulls maybe a pint of water on a good day. It is a backup for boondocking, not a solution for humid climates.
If you are asking which one to buy, the real question is whether you camp with hookups or off-grid. If you spend most of your time plugged in, buy the electric unit. If you boondock for weeks at a time, buy the 12-volt and accept that it will not keep up with heavy humidity. We own both because we do both.
How We Actually Keep Our RV Dry During Three-Month Humid Stays
We spent last summer parked in coastal Georgia from May through July. The humidity outside hit ninety percent most mornings, and inside the rig it climbed to seventy percent within an hour of waking up if we did not run the dehumidifier.
Our routine started every morning the same way. We cracked the roof vents in the bedroom and bathroom as soon as we woke up, even if it was already hot outside. The air exchange mattered more than keeping it cool. We ran the Ivation unit nonstop, checked the humidity level on a cheap digital hygrometer we stuck to the wall, and adjusted the setting if it climbed above fifty percent.
Showers were the worst. After one of us showered, the bathroom humidity spiked to eighty percent even with the vent fan running. We started leaving the bathroom door open and pointing a small fan toward the shower to push the moisture out into the main living area where the dehumidifier could grab it. It looked ridiculous, but it worked.
At night, we learned to crack a window in the bedroom even though it let in bugs and noise. Without that fresh air exchange, condensation formed on the inside of the windows by morning. We also stopped closing the bedroom door at night — the dehumidifier was in the living area, and closing the door trapped humid air in the bedroom with no way to pull it out.
The biggest adjustment was monitoring the tank even though we had it draining continuously. Twice the drain hose kinked and the tank filled up, which shut the unit off automatically. We did not notice for half a day, and by the time we caught it, the humidity had climbed back to sixty-five percent and everything felt damp again. Now we check the hose every few days and make sure water is actually draining.
We also stopped storing anything directly against exterior walls. Condensation forms on the inside of RV walls when the temperature outside drops at night, and anything pressed against those walls stays damp. We lost a stack of towels to mildew before we figured that out. Now we keep a few inches of clearance everywhere.
The whole system only works if you stay on top of it. We got lazy one week in late June, turned the dehumidifier off to save a few dollars on the electric bill, and within three days we had condensation on the windows again. Humidity does not take a break because you do. We learned similar lessons about staying consistent with our RV maintenance routines, and moisture control needs that same daily attention.
The Mistakes That Cost Us Money (And How We Fixed Them)
The first expensive mistake was buying a compressor-based dehumidifier for winter camping. We were in the Smoky Mountains in February, temperatures were dropping into the thirties at night, and the unit froze solid. The coils iced over, it stopped pulling any moisture, and we woke up to condensation dripping down the windows. Compressor units do not work below forty degrees. Desiccant models keep running down to freezing. We sold the compressor unit for half what we paid and bought the Ivation desiccant model. That one mistake cost us about seventy-five dollars.
The second mistake was ignoring the humidity level and running the dehumidifier on high all the time. We thought more power meant dryer air, but we were actually pulling too much moisture out. The wood trim in the rig started cracking, and we noticed the cabinet doors were not closing as smoothly. We bought a hygrometer, started monitoring the levels, and learned that thirty to fifty percent is the safe range. Below thirty, wood dries out and splits. Above fifty, mold starts growing. We now keep it right around forty-five percent, which is what the EPA recommends for indoor air quality.
The third mistake was assuming the RV dehumidifier would handle everything and ignoring ventilation. We kept the RV sealed up tight, ran the unit constantly, and still had condensation forming in the bedroom. It took us two weeks to realize the dehumidifier was only pulling moisture from the air in the living area. The bedroom door was closed, and humid air was trapped back there with nowhere to go. We started leaving doors open, running a small fan to circulate air, and cracking vents even when it felt counterintuitive. Dehumidifiers do not work in isolated pockets of dead air.
The last mistake was not draining it continuously from the start. We emptied the tank manually for the first month, which meant getting up every day to dump it. One morning we slept in, the tank filled up, the unit shut off, and by the time we noticed, the humidity had spiked back up. We rigged a drain hose to the gray tank after that and never looked back. If your dehumidifier has a drain option, use it. Emptying tanks gets old fast.
Before Your Next Humid-Climate Trip, Do This One Thing
Pull your mattress off the platform and check the wood underneath. Right now, before you leave.
If you see any dark spots, smell anything musty, or notice the wood feels damp, you already have a humidity problem and you do not know it yet. Clean it, dry it completely, and get a ventilation mat under that mattress before you park anywhere humid for more than a few days. We use a polymer mat that cost about thirty dollars and lifts the mattress enough to let air circulate. Without it, even the best RV dehumidifier will not stop condensation from forming in that dead space.
While the mattress is off, check the corners where the walls meet the floor. Look inside cabinets along exterior walls. Open storage compartments you have not touched in a month. Mold grows in the dark, and you will not see it until it has already spread.
If everything looks dry, you are ahead of where we were. Set up your RV dehumidifier now, test it, make sure it drains properly, and figure out where it needs to sit to pull air from the whole rig. Do not wait until you are parked in Florida in July and the humidity is already out of control.
We ignored the problem until we had black mold under our mattress and a three-day cleanup job ahead of us. You do not have to make the same mistake we did.
