Though you may not be aware of it, the amount of moisture in your apartment’s air has a big impact on how you feel and your overall health. A more humid environment will feel hotter. But how does AC affect the humidity in your home’s air? And, can you use your portable AC as a dehumidifier?
Does portable AC dry the air?
Yes, portable AC does dry the air. Moisture in the condenses when it comes into contact with your portable AC’s cooling element – the condenser coil.
You’ll get condensation whenever you put an icy object in a hot space. Buy a cold Starbucks drink on a hot day; little droplets of water will form outside the cup. That’s because the moisture in the air cools down when it touches the cup and goes from water vapor to just plain water.
The same thing happens inside any air conditioning unit. Air conditioners have a cooling element called a condenser coil that contains very cold liquid refrigerant. Water droplets form on the coil as the fan blows hot indoor air over the condenser coil
A portable air conditioner is designed to deal with these water droplets. Your unit will have a pump that moves water to a drip tray (aka condensate trap) that will fill steadily over time. You have to empty this tray periodically.
All the water that forms in your portable AC’s drip tray is water that’s no longer in the air. This might not be a problem if you live in a humid part of the country but otherwise, you should be conscious of some potential health risks of dry air.
Health benefits/risks of AC dehumidification
Beyond the benefits of cooler indoor temperatures, you should be aware that there are some health risks and benefits that come from less humid indoor air. First, the risks of AC dehumidifying your home:
- Skin irritation: Dry indoor air can be a pain for those with sensitive skin. With less moisture in the air, your skin will dry out more quickly and can become rough and itchy. You’ll want to be aware of this risk if you have a skin condition like eczema, which can get much worse after long periods in air-conditioned spaces.
- Itchy eyes: Air conditioning has a similar effect on your eyes. Lower moisture in the air will cause your eyes to dry out more quickly, leading to itchiness. Consider using eyedrops to mitigate this discomfort.
- Cough/respiratory irritation: Another area of the body where dry air can cause health problems is the throat and chest. Dry air can exacerbate any coughs or lung discomfort you’re experiencing.
But it’s not all bad. Depending on who you are and your personal health situation, there can be a lot of upsides to living in drier indoor spaces. Here are some health benefits of air conditioning:
- Lower risk of mold: This is a big benefit of using air conditioning. Mold loves hot, wet spaces so reducing air moisture is a great way to make it harder for mold to grow. Leaving mold unattended could cause respiratory problems as mold spores get into your lungs when you breathe them in.
- Less heat-related risks: This one is quite obvious but you’re less likely to suffer from heat stroke or dehydration when you’re in a cooler environment. Drier air is likely to increase your risk of dehydration but not as much as sweating through your clothes all day.
Portable AC vs Dehumidifier: Which works better?
A portable AC and dehumidifier work in exactly the same way to dehumidify the air in your home. As a result, neither is better than the other at dehumidification. The only difference is the type of model.
You should expect to pay more for a portable AC given it has the ability to actually cool your home. It wouldn’t make sense to pay for a portable AC if you only plan to use it as a dehumidifier.
A dehumidifier has a hot side and a cold side just like a portable AC. The cold side causes moisture in the air to form water condenses and form water droplets, which are then collected in a drip tray. This is exactly how a portable AC works.
The only difference between a dehumidifier and a portable AC is that the portable AC has the capacity to go much colder. The cooling element in a dehumidifier doesn’t need to be freezing cold to get moisture to condense – it just needs to be below the water’s dew point at the current level of humidity.
But a portable AC in dehumidification mode will reduce its fan speed and increase the temperature of its cooling element to operate in the same way as a dehumidifier. The goal is to increase the amount of time air is in contact with the cooling element so that water droplets can form.
Do I need to vent my portable AC in dehumidifier mode?
No, you don’t need to vent your portable AC in dehumidifier mode. The only exception to this is if your portable AC uses vapor cooling to help keep its compressor cold.
The purpose of venting a portable AC during air conditioning is to get rid of the excess heat produced during the process. That excess heat is not a problem if your only goal is to dehumidify your space. The consequence of not venting your portable AC would be that your home’s temperature stays the same.
Some types of portable ACs use vapor cooling to help make the process of compression more efficient. Basically, your portable AC uses the water in the condensate tray to cool down hot pipes. But this process produces evaporation that would counteract the dehumidifying benefits of air conditioning.
You should be able to find out whether your portable AC uses vapor cooling by checking the manufacturer’s guidelines. If it does, there’s a good chance that your device will stop vapor cooling during the dehumidification process.
How to set your portable AC to dehumidifier mode?
You can set your portable AC to dehumidifier mode in a few easy steps. First, find the dehumidifier mode in your portable AC’s settings either on your remote or the unit’s controls. Second, set your desired humidity level. Finally, make sure you empty the water tank before it fills up.
Mark is a journalist who has written about home products for two years. He holds a masters degree with distinction from the London School of Economics and an undergraduate degree from the University of Edinburgh.