Dehumidifiers shouldn’t be used when temperatures are below 60°F or when relative humidity falls under 50%. They should also be turned off at night time and during cleaning, and installation or replacement of filters. Dehumidifiers can also be switched off for the winter if you live in a cold, dry area.
Dehumidifiers are essential in hot and humid areas or in parts of a house where it’s naturally more humid, like a basement. But there are times when it’s important to turn off your dehumidifier.
In this article, we explain when and why you should switch off your dehumidifier.
8 Reasons To Turn Off Your Dehumidifier
The average lifespan of a dehumidifier is 5 to 10 years. But for a dehumidifier to last that long, it needs to be looked after.
And that includes turning off your dehumidifier when it shouldn’t be running. Here’s when you should turn your dehumidifier off:
1. Winter
The efficiency of a dehumidifier is proportional to humidity and warm temperature. This means they are best suited to summers when the temperature and humidity levels are higher.
In winter, the average relative humidity is 30%-40%, and using a dehumidifier would decrease it further and make the air ‘dry’. In fact, according to Energy Star, the optimum relative humidity is 30-50% – the natural humidity level during Winter.
The coils of a dehumidifier are prone to frost in winters and should not be operated in temperatures below 60° F.
Low temperatures can cause the system to freeze, and the defrost system usually with the in doesn’t work properly when there’s an influx of extremely cold air. The moisture that the dehumidifier removes from the air freezes on the cooling coils after condensing, which not only stops it working properly, but can also damage it.
It’s always best to turn your dehumidifier off in winter to prevent damage. Unless of course you live in the tropics, in which case your temperature and humidity levels might be still be high enough to run one safely.
Another exception are basement dehumidifiers, if it’s warm and humid enough – then keep them running.
2. Night Time
Humidity at night is lower than during the day. If the humidity drops to less than 30% to 50% at night, it’s better to switch off the dehumidifier and only run the system in the daytime.
Humidity levels are higher during the day because the warmer daytime air can hold more moisture, so it’s only natural to use a dehumidifier. But at nighttime the moisture in the air is already lower and your room usually doesn’t a dehumidifier.
This will depend on where you live. Instead of turning your dehumidifier off every night, just check the humidity. If your humidity is less than 50% turn it off, if it’s above then keep using it!
And even if you do experience hot and humid nights, it’s ideal if you can shut it off for at least two hours a day to let it cool.
3. Relative Humidity (RH) Below 30% Range
Humidity levels below the 30% range can be uncomfortable. The air can turn severely dry, causing irritation and itching.
Low relative humidity can also happen if the condenser of your humidifier is faulty, which puts it into overdrive.
When this happens, immediately turn the dehumidifier off to prevent further dehumidification, and check if you have set an extremely low level of RH on humidistat or if the local humidity has dropped.
4. Dehumidifier Making Weird Noises
While your dehumidifier will probably make a characteristic starting noise, any weird sounds coming out of it are not normal.
A dehumidifier is usually noisy because of loose or damaged parts, especially the fan, but also screws and brackets. The compressor acting up can also make a lot of noise.
If you ever hear an unusual sound coming out of your dehumidifier, turn it off immediately as letting it run can cause more damage. Find out the cause of the sound, fix it and then turn it back on.
Plentiful Air has a troubleshooting guide for noisy dehumidifiers available here.
5. Dehumidifier Releasing Cold or Hot Air
The dry air that comes out of a dehumidifier is warm, but it’s not so warm that it makes a difference to the temperature of the room. It should also never feel hot or cold.
If your dehumidifier is blowing cold or hot air turn it off immediately.
Cold air can be a result of freezing coils or a technical problem preventing the system from going into defrost mode.
You can find more information on why your dehumidifier is blowing cold air here.
While hot air can be caused by low refrigerant, a burnt capacitor or corroded coils.
Either option is not good, so make sure your dehumidifier is off while you figure out the problem.
5. Replacing the Filter
A dehumidifier must be switched off before replacing its filter. Okay, this might seem like an obvious reason to turn off your dehumidifier, but you’d be surprised!
Most dehumidifiers come with air filters that collect large bits of dirt, mold, and other contaminants from the air before it takes the moisture from it.
The filter needs to be changed at least every 12 months, but it’s best to check your user manual as some recommend changing them sooner.
Always turn off your dehumidifier when replacing the filter.
6. Cleaning
It’s generally recommended to clean your dehumidifier once every week, by separating all the parts and cleaning them individually.
While usually, a clean, dry brush is enough for coils and filters, you need a damp cloth to clear off any hardened debris. To clean the bucket and reservoir, you’ll need detergent and demineralized water.
The dehumidifier should not only be turned off, but unplugged before disassembling and cleaning it.
Once dry, reassemble the system and only then turn it on.
7. Installation
A dehumidifier is an electronic device, so leaving it on during installation or service is a safety hazard. Any fault in wiring can cause a short circuit, it’ better to plug it into the socket only after installation is complete.
Related Questions
Can I Leave My Dehumidifier on 24/7?
A dehumidifier should not be left on 24/7 as it can overload the unit and cause it to malfunction. Since humidity levels at daytime are usually above 50%, it’s better to run the humidifier during the day and then unplug it at night.
The working capacity of a dehumidifier varies depending on its size, type, and manufacturing. Generally, all the appliances can extract enough moisture to bring the humidity levels to 50-55%. Based on this, it’s generally recommended to run the dehumidifier for 12 hours and turn it off afterward.
Even if you experience hot and humid nights, it is better to shut the system off for at least two hours a day to let it cool. Otherwise, leaving dehumidifiers on all the time can overload, and it can start to malfunction. Especially smaller units.
Ultimately, how long you should leave the dehumidifier on depends on its size, features, type, extraction capacity, power consumption, etc. But ideally, it’s best not run it for more than 12 hours in a single session.
Should I Turn Off My Dehumidifier at Night?
Dehumidifiers should be turned off at night if the relative humidity falls to 50% or below.
Generally, in summers, the temperature stays hot during day time and falls to a comfortable extent at night.
Dehumidifiers work best in warm temperatures, and when used at night, they won’t work efficiently if the nighttime temperature is quite low.
Does a Dehumidifier Automatically Shut Off?
Dehumidifiers automatically turn off when the room reaches the set humidity level or when the water tank is full (depending on the model).
You can set the relative humidity level in the dehumidifier as per your comfort. The humidistat senses the relative humidity, and once the room air reaches that level, it will shut off. This is done to prevent further dehumidifying.
This holds true for water reservoirs as well. The moisture removed from the air collects in the reservoir. Once they are full, the dehumidifier turns off automatically to avoid spillage.
To keep the system running, you should empty the reservoir at least once a day or have a drain system, so water can drain out continuously.
When Should I Turn Off My Basement Dehumidifier?
As basements are generally warm, humid, and prone to mold development, closely monitor the temperature and turn the dehumidifier off only when the temperature drops below 60°F.
Dehumidifiers keep the air adequately dry and, in the process, prevent the build-up of mold and bacteria in basements. Wet environments and damp surfaces are breeding grounds for molds and bacteria, which can damage both your health and your home.
Dehumidifiers reduce the humidity in the room and can save it from damage.
Basements are devoid of sunlight and are warm and humid, so they have a higher chance of mold. You should turn your basement dehumidifier off only when the temperature falls below 60°F, or the relative humidity is under 30 to 50%.
If the basement feels exceptionally wet, you may even need to run the appliance all day long.
This stands for winters as well because in-house heating systems keep the basement warm in cold temperatures, and to prevent mold and mildew, you might still need a dehumidifier.
Conclusion
We hope this article helps you understand when it is imperative to turn your dehumidifier off. Dehumidifiers are important appliances as they can help keep humidity under control, especially during summers and in areas like basements, which are susceptible to mold. At the same time, only use it when needed and switch it off when it’s running unnecessarily.
