Yes, you can run an RV dehumidifier with the air conditioner when indoor humidity stays high. However, you usually do not need both if your RV AC already keeps relative humidity around 40% to 55%. Running both can remove moisture faster, but the dehumidifier also uses electricity and releases some heat inside the RV.
The best setup depends on the weather, your RV’s humidity level, and available electrical power. Below, I’ll show you when to run both, when the AC alone is enough, and how to manage humidity without overloading your RV electrical system.
Key Takeaways
- You can run an RV AC and dehumidifier simultaneously.
- Try your air conditioner alone before adding a dehumidifier.
- Consider running both when humidity stays above 55% to 60%.
- A dehumidifier removes moisture but also adds some indoor heat.
- Running both does not automatically reduce AC electricity use.
- Watch your total electrical load carefully on 30-amp service.
- Use a hygrometer instead of judging humidity by how the RV feels.
- A built-in AC Dry mode may replace a separate dehumidifier.
Should You Run an RV Dehumidifier With the Air Conditioner?
You should run an RV dehumidifier with the air conditioner when the AC keeps the RV cool but the air still feels damp or your humidity meter remains above about 55% to 60%.
This situation is especially common during hot, humid weather. You may experience it while camping in Florida, along the Gulf Coast, near the ocean, or during long periods of summer rain.
Your RV air conditioner already removes moisture while cooling. Because of that, I would not automatically switch on both appliances every time the AC runs.
Start with the AC.
Give the RV enough time to cool down and stabilize. Then check your indoor relative humidity with a digital hygrometer.
If the reading settles somewhere around 40% to 55%, your AC is probably doing enough.
If humidity stays near or above 60%, adding a dehumidifier can provide extra moisture control.
There is one important point I want you to remember.
A dehumidifier does not simply take over the moisture-removal job and allow your air conditioner to use all its energy for cooling. A compressor dehumidifier produces some heat while operating.
That extra heat stays inside your RV.
So, while running both can make the air feel much drier and more comfortable, your AC may still need to remove some of the heat created by the dehumidifier.
The real benefit is better humidity control, not guaranteed lower electricity consumption.
How Does an RV Air Conditioner Remove Humidity?
Your RV air conditioner does more than lower the temperature. Whenever humid indoor air passes across the cold evaporator coil, some moisture condenses into water and drains away from the RV.
Cooling and Dehumidification Happen Together
Warm indoor air contains water vapor.
When your RV air conditioner pulls that air across its cold evaporator coil, the temperature of the air drops. If the coil becomes colder than the air’s dew point, moisture condenses on the coil.
That water eventually drains outside.
This is why you may notice water dripping from your rooftop AC during humid summer weather. In many cases, that dripping water simply shows that the system is removing moisture as designed.
The longer the compressor runs, the more opportunity the AC has to remove humidity.
Why the AC May Not Remove Enough Moisture
Sometimes your RV becomes cool before enough moisture has been removed.
This commonly happens when:
- The AC compressor runs in short cycles.
- Outdoor temperatures are mild but humidity is high.
- Your RV cools down very quickly.
- Doors are opened frequently.
- Several people are staying inside the RV.
- You cook frequently inside.
- Hot showers release moisture into the RV.
- Wet towels or clothing are drying indoors.
- Humid outside air leaks through gaps.
- You are camping in a very humid climate.
Nighttime can be particularly tricky.
The outside temperature may fall enough that the AC rarely needs to run. However, the humidity can remain high.
That is when a separate dehumidifier can become much more useful.
What Happens When You Run the AC and Dehumidifier Together?
Running both appliances gives your RV two separate systems removing moisture. That can lower humidity faster, but it also increases electrical demand and introduces some additional indoor heat.
The AC Removes Heat and Moisture
Your air conditioner removes sensible heat from the RV while also collecting moisture on the evaporator coil.
That makes it particularly effective during hot, humid weather because you need cooling and moisture removal at the same time.
If the AC runs for reasonably long cycles, you may not need another appliance at all.
The Dehumidifier Removes Moisture but Adds Some Heat
A typical compressor dehumidifier also uses a cold coil to condense moisture.
However, unlike your RV air conditioner, the dehumidifier does not send heat outside.
It cools the air enough to collect moisture and then passes that dried air across a warmer coil before returning it to the room.
As a result, the air leaving the dehumidifier usually feels slightly warmer.
In cool or mild weather, that small amount of extra heat may not bother you.
During very hot weather, your RV air conditioner may need to remove that additional heat.
Does a Dehumidifier Make the RV AC Work Less?
Sometimes it can make the RV feel more comfortable without requiring you to lower the thermostat as much.
Dry air generally feels more comfortable than humid air at the same temperature.
For example, you may feel comfortable at 76°F with moderate humidity but uncomfortable at the same temperature when the RV feels sticky and damp.
However, I would not say that adding a dehumidifier always makes your air conditioner work less.
The dehumidifier consumes electricity and releases heat.
Think of it primarily as a humidity-control tool, rather than an energy-saving upgrade for your AC.
When Should You Run Both at the Same Time?
The easiest way to decide is to look at temperature and humidity together. Your hygrometer can tell you much more than simply touching the walls or judging whether the RV feels sticky.
| RV Condition | Indoor Humidity | Best Choice | Why |
| Hot and moderately humid | 40%–55% | AC alone | The AC is already controlling heat and moisture |
| Hot and very humid | Above 55%–60% | AC + dehumidifier | Additional moisture removal may help |
| Warm but not hot | Above 60% | Dehumidifier | AC may cool the RV unnecessarily |
| Cool nighttime weather | Humidity rising | Dehumidifier | AC may not run long enough |
| After cooking or showering | Temporary humidity spike | Exhaust fan first | Remove moisture near its source |
| AC has Dry mode | Elevated humidity | Try Dry mode first | A separate appliance may not be necessary |
| Boondocking | Elevated humidity | Use cautiously | Both appliances can consume substantial power |
The table gives you a starting point, but your RV may behave differently.
Occupancy, insulation, outdoor weather, AC size, air leakage, and moisture sources all affect the result.
What Humidity Level Should You Maintain Inside an RV?
For normal warm-weather RV living, I recommend trying to keep indoor relative humidity around 40% to 55% whenever practical.
Do not panic if the number briefly climbs higher after showering or cooking.
Short humidity spikes are normal.
The bigger concern is humidity that remains around or above 60% for long periods.
Persistent high humidity can contribute to:
- Window condensation
- Damp mattresses
- Moisture behind cushions
- Musty odors
- Mold growth
- Damp cabinets
- Moisture damage around cold surfaces
During cold-weather camping, you may need to keep humidity even lower because cold windows and exterior walls can collect condensation more easily.
A small digital hygrometer is one of the simplest tools you can keep inside your RV.
Instead of guessing, you can look at the number and make a decision.
How Do You Know the RV AC Alone Isn’t Enough?
You do not need to add another appliance simply because the weather feels humid. Look for measurable or repeated signs that the AC is not controlling moisture adequately.
- Humidity remains above about 55% to 60%.
- Windows stay fogged or wet.
- Walls feel damp or clammy.
- Bedding feels slightly moist.
- Closets develop a musty smell.
- Moisture appears behind cushions.
- The mattress feels damp underneath.
- Humidity climbs quickly after the AC stops.
- The RV feels sticky even though it is cool.
- Condensation keeps returning overnight.
If you notice one of these signs, check your hygrometer before making changes.
The actual humidity reading is more reliable than comfort alone.
Can You Run an RV Dehumidifier and AC on 30-Amp Service?
You can often run an RV air conditioner and dehumidifier together on 30-amp service, but you need to watch the total load. A 30-amp RV has approximately 3,600 watts of maximum available 120-volt power.
Calculate Your Actual AC and Dehumidifier Load
Do not assume every rooftop AC or dehumidifier consumes the same amount of electricity.
Check the equipment labels or owner’s manuals.
You can estimate amperage using:
Watts ÷ Volts = Amps
For example, if your dehumidifier draws 500 watts:
500 ÷ 120 = about 4.2 amps
Your rooftop AC may consume well over 10 amps while operating, depending on its size and design.
Starting the compressor can also cause a short surge above its normal running current.
Running the AC and a small dehumidifier may therefore be manageable.
Problems usually appear when several high-draw appliances operate simultaneously.
Watch Other High-Draw RV Appliances
Be especially careful when using:
- Microwave ovens
- Electric water heaters
- Induction cooktops
- Hair dryers
- Electric space heaters
- Coffee makers
- Toasters
- Second rooftop air conditioners
You may have enough capacity for your AC and dehumidifier but trip the breaker when somebody turns on the microwave.
Load management matters more than simply asking whether two appliances can operate together.
What About a 50-Amp RV?
A 50-amp RV has much more available electrical capacity.
Unlike 30-amp service, a typical 50-amp RV connection provides two 120-volt legs, giving you up to approximately 12,000 watts of total available power.
That makes simultaneous AC and dehumidifier operation much easier.
However, individual branch circuits still have their own breaker limits.
You should never overload a specific outlet or circuit simply because the RV has 50-amp shore power.
What About Running Both on a Generator or Battery Power?
You need to be more selective when using a generator, inverter, or battery bank because both compressor appliances can consume a considerable amount of power.
With a generator, check its continuous output rating, not only the large peak-watt number printed on the housing.
Your generator needs enough capacity to support the normal running load and handle the AC compressor starting surge.
A soft-start device can reduce AC startup demand on compatible systems, but it does not eliminate normal running power consumption.
Battery-powered operation deserves even more attention.
An RV rooftop AC can drain a modest battery bank quickly. Adding a compressor dehumidifier increases that demand further.
How long your batteries will last depends on:
- Battery capacity
- Battery chemistry
- Inverter efficiency
- AC power draw
- Dehumidifier power draw
- Outdoor temperature
- Thermostat setting
- Compressor cycling frequency
- Solar charging input
For that reason, shore power is usually the easiest situation for running both appliances for long periods.
When boondocking, I would first reduce moisture at its source before automatically running two compressor appliances.
What If Your RV Air Conditioner Has a Dry Mode?
Before you buy or switch on another dehumidifier, check your air conditioner controls. Some newer RV climate systems include a dedicated humidity-control setting.
Look for settings labeled:
- Dry
- Dehumidify
- Dehumidification
- Humidity Control
Dry mode normally changes how the AC compressor and fan operate so the system can remove moisture without aggressively lowering the indoor temperature.
This can be very useful at night or during rainy weather.
Try the built-in mode first.
Then monitor your hygrometer.
If it keeps the RV somewhere around 40% to 55% RH, you probably do not need to run another compressor appliance at the same time.
If humidity remains elevated, a separate dehumidifier may still help.
How to Run an RV Dehumidifier With the AC Efficiently
You do not need to run both appliances at maximum settings all day. A simple humidity-based routine can control moisture while keeping electrical use reasonable.
- Place a digital hygrometer in your main living area.
- Run the RV air conditioner normally first.
- Allow the temperature and humidity to stabilize.
- Check whether RH remains above roughly 55% to 60%.
- Turn on the dehumidifier if additional moisture removal is needed.
- Set the dehumidifier around 45% to 55%.
- Keep windows and exterior doors closed while cooling.
- Use bathroom exhaust ventilation while showering.
- Use the range vent while producing cooking steam.
- Avoid drying wet clothing inside whenever possible.
- Keep AC filters clean.
- Keep return-air and supply vents unobstructed.
- Check your electrical load before using another large appliance.
- Set up safe continuous drainage if your dehumidifier supports it.
- Recheck the hygrometer instead of leaving both appliances running automatically.
Once the RV reaches a stable humidity level, the dehumidifier should cycle off if you are using an automatic humidity setting.
That is more efficient than selecting continuous operation unnecessarily.
Where Should You Put the Dehumidifier Inside the RV?
Place your dehumidifier where it can pull air freely from the main RV living space.
The floor or another stable, level surface often works well.
Avoid pushing the unit tightly against furniture, curtains, walls, or cabinets. Both the intake and exhaust need proper airflow.
Follow the clearance instructions provided for your specific model.
A central location can work better than hiding the dehumidifier inside a closed bathroom because air from the rest of the RV needs to reach it.
Also think about drainage.
If you plan to use a hose, choose a location where you can route it safely without creating a tripping hazard.
Never leave the dehumidifier loose while driving.
Portable appliances should be secured before traveling.
How Should You Drain an RV Dehumidifier?
Most portable dehumidifiers either collect water in an internal bucket or allow continuous drainage through a hose. Your best option depends on how often you use the unit.
Using the Collection Bucket
The built-in bucket is convenient when you only need occasional moisture control.
When the bucket fills, most modern dehumidifiers stop automatically.
The disadvantage appears in extremely humid weather.
Inside a small RV, a capable dehumidifier may collect water surprisingly quickly. You might need to empty the bucket several times per day.
Check it regularly until you understand how quickly your particular setup fills.
Using Continuous Drainage
Continuous drainage can be much more convenient during extended humid weather.
If your dehumidifier supports gravity drainage, route the hose according to the manufacturer’s instructions.
Make sure:
- The hose remains securely connected.
- Water can flow downhill.
- The hose is not kinked.
- The drain point cannot overflow.
- The hose cannot become a tripping hazard.
Some RV owners route the hose into a shower pan or suitable drain.
That can work, but remember where the water goes.
If it enters your RV plumbing system, it may eventually increase the amount of water in your gray tank.
Keep an eye on tank capacity when you are not connected to a sewer hookup.
Should You Leave Windows and Roof Vents Open?
Generally, keep windows and unnecessary roof vents closed while your AC and dehumidifier are trying to condition humid outdoor air.
Otherwise, both appliances keep treating new humid air entering the RV.
However, there is an important exception.
You should still remove moisture at its source.
When showering, use your bathroom exhaust fan.
When boiling water or cooking something that produces lots of steam, use a properly vented range fan if your RV has one.
Once the moisture-producing activity ends, close unnecessary openings again.
That approach is different from leaving a window cracked all day while trying to dehumidify the RV.
Short-term source ventilation helps.
Continuous uncontrolled humid-air entry usually does not.
When Is a Dehumidifier Unnecessary?
A separate dehumidifier may offer little benefit if your RV air conditioner is already controlling moisture successfully.
- Indoor RH stays around 40% to 55%.
- Windows remain dry.
- Bedding does not feel damp.
- No musty smell develops.
- You are camping in a dry climate.
- Your AC runs long enough to remove moisture.
- Built-in Dry mode maintains comfortable humidity.
- You are trying to conserve generator fuel.
- You are trying to conserve battery power.
Do not feel that you must run a dehumidifier simply because you own one.
Let the hygrometer make the decision.
If humidity is already controlled, another appliance is mostly adding electricity use and heat.
When Should You Use the Dehumidifier Without the AC?
There are plenty of times when running only the dehumidifier makes more sense.
Consider using the dehumidifier alone when:
- The RV feels humid but not hot.
- Nighttime temperatures are comfortable.
- Rainy weather raises indoor humidity.
- Your AC barely runs because the thermostat is satisfied.
- You want moisture control without making the RV colder.
- Humidity remains high after showering or cooking.
- You are dealing with moisture during suitable storage conditions.
This is one of the biggest advantages of having a separate dehumidifier.
Your humidity problem does not always happen at the same time as your cooling problem.
Can High Humidity Mean Something Is Wrong With the RV?
High outdoor humidity can certainly make the inside of an RV damp, but persistent moisture should not always be blamed on the weather. If the humidity stays unusually high despite dehumidification, look for another moisture source.
Check for Plumbing or Exterior Water Leaks
Inspect common water-entry points around:
- Roof seams
- Windows
- Doors
- Slide-out seals
- Plumbing fittings
- Water heater connections
- Shower plumbing
- Toilet connections
- Under-sink areas
Feel around flooring, cabinet corners, and exterior walls.
A small hidden leak can keep releasing moisture faster than your AC or dehumidifier can remove it.
Check the RV Air Conditioner
If the AC used to control humidity well but suddenly stops doing so, check the system.
Common things worth inspecting include:
- Dirty air filters
- Restricted return airflow
- Blocked supply vents
- Frozen evaporator coils
- Poor condensate drainage
- Very short compressor cycles
If you notice unusual AC behavior, address that issue before assuming you need a larger dehumidifier.
Look for Hidden Moisture Sources
Your everyday RV routine can also produce surprising amounts of moisture.
Common sources include:
- Wet bath towels
- Indoor clothes drying
- Shower steam
- Boiling water
- Cooking
- Wet camping equipment
- Damp shoes
- Several sleeping occupants
- Moist mattresses
- Wet pet gear
Start with the easiest moisture sources first.
Removing water before it enters the indoor air is usually more efficient than removing it later with another appliance.
RV AC Alone vs. Dehumidifier Alone vs. Both
Each setup solves a slightly different problem. The right choice depends on whether you primarily need cooling, moisture removal, or both.
| Setup | Removes Humidity | Cools RV | Adds Indoor Heat | Power Demand | Best Use |
| RV AC only | Yes | Yes | No | High | Hot weather with manageable humidity |
| Dehumidifier only | Yes | No | Slightly | Low to moderate | Humid but mild weather |
| AC + dehumidifier | Strong moisture control | Yes | Slightly from dehumidifier | Highest | Very hot and humid conditions |
| AC Dry mode | Yes | Limited cooling | No separate appliance heat | Varies | Humid conditions without heavy cooling needs |
If you’re unsure where to start, use the AC first during hot weather.
Then add the dehumidifier only when your humidity reading shows that you need extra moisture removal.
Final Verdict
So, should you run an RV dehumidifier with the air conditioner?
Yes, when your RV remains too humid after the air conditioner has been running.
I would start with the AC by itself and monitor the indoor humidity. If your hygrometer settles around 40% to 55%, you probably do not need anything else.
If humidity remains close to or above 60%, adding a dehumidifier can help protect your RV from condensation, damp bedding, musty odors, and long-term moisture problems.
Just remember that the dehumidifier adds electrical load and releases some heat inside.
On 30-amp service, manage your other appliances carefully. If your AC has a Dry mode, try that before running a second compressor appliance.
The goal is not to keep every appliance running.
The goal is simply to keep your RV cool, dry, and comfortable with the least complicated setup that works.
Related FAQs
Does an RV Air Conditioner Dehumidify the Air?
Yes. An RV air conditioner removes moisture when humid indoor air passes across its cold evaporator coil and water vapor condenses. The moisture then drains away while the cooled air returns inside.
Does a Dehumidifier Help an RV AC Cool Better?
A dehumidifier can make your RV feel more comfortable because lower humidity reduces that sticky feeling, but it does not necessarily reduce AC power use. The dehumidifier also produces some heat that the AC may need to remove.
Can I Run a Dehumidifier and RV AC on 30-Amps?
You can often run both on 30-amp service if their combined electrical load stays within your available capacity. Avoid operating several other high-draw appliances, such as the microwave or electric water heater, at the same time.
What Humidity Should I Set My RV Dehumidifier To?
A setting around 45% to 55% relative humidity works well for most warm-weather RV conditions. You generally want to avoid prolonged indoor humidity around or above 60%.
Should I Run My RV Dehumidifier All Night?
You can run it overnight if humidity requires it, the unit is safely positioned, drainage is handled correctly, and your electrical supply can support it. An automatic humidity setting is usually better than continuous operation.
Will a Dehumidifier Make My RV Hotter?
Yes, slightly. Compressor dehumidifiers release some heat into the surrounding room while operating, so you may notice warmer discharge air coming from the unit.
Is a Dehumidifier Necessary If My RV AC Has a Dry Mode?
Not always. Try your AC’s Dry or Dehumidification mode first and watch your hygrometer. If it maintains comfortable humidity, running another appliance may be unnecessary.
Should I Use a Dehumidifier in an RV in Florida?
A dehumidifier can be very helpful in Florida because outdoor humidity is often high. If your AC keeps the RV cool but indoor humidity remains elevated, running both can provide better moisture control.
Is 60% Humidity Too High for an RV?
Sixty percent is near the upper limit you generally want inside an RV. Brief spikes are usually manageable, but humidity that remains around or above 60% can increase condensation and moisture problems.
Where Should I Put a Dehumidifier in My RV?
Place it on a stable, level surface in an open part of the RV where air can move freely around the intake and exhaust. Follow the clearance requirements provided by the dehumidifier manufacturer.
Should RV Windows Be Closed When Running a Dehumidifier?
Generally, yes. Keeping windows closed prevents humid outside air from continuously entering the RV. You can still briefly use exhaust ventilation while showering or cooking to remove moisture directly at its source.
Kevin Thompson documents RV travel lessons, planning tips, and gear reviews drawn from hands-on use. His writing is practical, direct, and easy to follow. Readers rely on his notes to make smarter RV buying and travel decisions.
