Does Air Conditioning Dehumidify? The Comfort From Dual Function AC

Air Conditioning, Dehumidifiers

Summer in the US is fast approaching and we can already feel the beginning of the warmer seasons. Sources say it will be “sizzling” this 2023 with as high as over 110 degrees in specific locations in the country. Many households are already getting their air conditioners ready to fight the summer heat with processed cool air.

But more than the heat, many people are anxious about how humid it will be in their homes. The high humidity level is the number one challenger for comfortable indoor living, not just in America but in plenty of homes worldwide.

Can your air conditioning save you from this enemy humidity? Does air conditioning dehumidify? Besides cooling, does your air conditioner remove the excess moisture from the air?  

Let us take a look at how the air conditioner provides more than just cooler air but dehumidifying convenience as well.

does air conditioning dehumidify

Can Air Conditioning Dehumidify Your Home?

YES, the air conditioner dehumidifies your home, as well as cools the air. 

As the AC is turned on, it draws the warm air from the room and passes it over the cold coils. The heat and the moisture are separated from the air. The air now free from heat and humidity will be blown back into the room. This cooling process will continue until the room temperature measured by the thermostat matches your preferred setting of comfort.

The dual function of AC to cool the air and dehumidify makes it an ideal device for maintaining comfort indoors in hot and humid weather. 

Although air conditioners can achieve a small amount of dehumidification while operating in cooling mode, their main function is to lower the temperature. Pairing a dehumidifier with your air conditioner can give you maximum relief in extremely damp climates.

The Relationship Between Temperature and Relative Humidity

Many mistakes heat for what makes them unbearably uncomfortable. The harsh truth is it is not JUST the heat that makes you sweaty and irritable but its friend, the humidity.

When water is exposed to heat, it evaporates. Humidity is simply water in the form of gas. You can also refer to humidity as water vapor or moisture in the air. 

Now, there are two classifications of humidity: absolute humidity and relative humidity. Absolute humidity pertains to the amount of water vapor in the atmosphere regardless of the temperature. A subtype of absolute humidity is specific humidity or the moisture in a specific unit of weight of air.

The second classification is relative humidity. It refers to absolute humidity but is RELATIVE to the air’s temperature. You may be more familiar with relative humidity as it is more widely used in weather news or forecasts expressed in percentage. (Example: 45% humidity during the summer or 25% humidity in the winter.)

Why do weather forecasts focus more on relative humidity than absolute? Because the former plays a much bigger role in what we perceive as “comfortable”.

You see, relative humidity is tricky because as you feel hot, your body naturally produces sweat. But in a place where the relative humidity is high–meaning, there is already too much water vapor present in the air–your sweat can no longer evaporate. And when your sweat cannot leave your skin, your body cannot cool itself off and you feel rather icky.

So the temperature might just be 105 degrees but it feels like 122 degrees or higher because the humidity aggravates the hot feeling. 

How Heat and Amount of Moisture Impact Indoor Air Quality

Levels of heat and humidity not only affect how cool or warm we feel inside our homes but greatly impact indoor air quality.

Indoor air quality refers to the status or condition of air in enclosed spaces such as residences, offices, and public areas that relate to the health and comfort of the occupants.

It is quite obvious that the comfort of occupants suffers when there’s too much humidity in a home. Not only do you feel hot and sticky, but it can reach a point where you feel drowsy and lethargic. In worst cases, one can even experience hyperthermia where the body overheats because it cannot get rid of its heat properly.

Another way the indoor air quality of a home declines when the water vapor is excessively high is through the growth of biological contaminants indoors. These include mold, mildew, dust mites, bacteria, viruses, cockroaches, and other insects. They thrive and propagate in damp or humid places around the house. 

Allergies, irritation, asthma, and even infection can be induced because of these indoor pollutants. Such health risks make humidity a top priority in managing home comfort.

Do Air Conditioners Dehumidify?

To answer the question, “Do air conditioners dehumidify?”, we have to trace back the rich history of modern HVAC. 

The modern air conditioner designed by Willis Carrier has been around since 1902, but the earliest version of this cooling invention came as early as 1848. But back then, it was called the “ice-making machine”.

Carrier’s contemporary version which came a few years later does not have cooling as its primary function. While working in a publishing company, he was tasked to solve the problem of magazine pages wrinkling because of excess moisture in the air. 

To remedy this issue, Carrier invented a system that can control humidity using cooling coils with cold water. He also found that the reverse process of heating water can increase humidity. Thus, he became known as the “Father of Air Conditioning”.

So truly, dehumidification is at the heart of the air conditioning process. It is no surprise then that until today, advanced designs of AC still involve using the cooling substance refrigerant to manage the humidity levels of your home.

The dehumidification process starts when the cooling also initiates. The thermostat makes a reading of the current temperature in your home and compares it with the desired setting you input into the device. When there is a discrepancy between the thermostat setting and the temperature reading, the air conditioner begins to operate.

When the AC is turned on, it draws the warm air from the room and passes it over a series of cold coils. Each coil contains refrigerant which absorbs the heat and condenses the moisture from the air. The heat and the moisture then separate from the air. 

The air now free from heat and humidity will be blown back into the room. This cooling process will continue until the room temperature measured by the thermostat matches your preferred setting of comfort.

Factors Affecting the Dehumidifying Power of Air Conditioners

While a singular unit of air conditioner does the job of virtually two devices, several factors impact the dehumidification capabilities of air conditioning that we need to consider. These include AC size and capacity, temperature and fan settings, and climate and local environment.

Air Conditioner Size and Capacity

Air conditioners come in varied sizes and power or capacity. These should match perfectly with the measurements of the room it is supposed to cool. Otherwise, having too small or too big a unit may impact how effectively your AC dehumidifies.

If the air conditioner is too small, it will fail to cool a sizeable room. It will also work twice as hard to remove the humidity. Because it is constantly running just to meet the thermostat requirement, your utility bill may run high but without the comfort you expect.

On the other extreme, if the AC unit is too big for the space, it will quickly lower the temperature of the room but too quickly that it fails to remove the excess moisture. This unfortunate scenario is called short-cycling, where the air conditioner fails to complete a cycle and shuts off before it can dehumidify your home properly.

Temperature and Fan Settings

Warm air can hold more moisture than cool air. That is why it feels more humid and uncomfortable in hot weather conditions than in cold ones. Setting your AC to cooling mode can help reduce the humidity.

You can also set the fan setting to “Auto” instead of “On”. This will prevent the excess water vapor to be blown back into your home but instead, stay within the mechanism to be collected. The collected condensation will also drain the right way instead of being cycled back into the air.

Climate and Environment

The last thing that may limit the dehumidifying performance of your air conditioner is the local climate and humidity levels in your area. 

States such as Florida, Georgia, Alabama, and Mississippi are some of the most humid locations in the country. Places close to bodies of water such as lakes and oceans tend to be more humid because there is an abundant supply of water that evaporates into the air when the temperature rises. 

If you live in such areas, air conditioning may not be enough to manage the humidity inside your home. In this case, a dehumidifier may come in handy.

What is a dehumidifier and how is it different from an air conditioner?

The Difference Between Air Conditioners and Dehumidifiers

While the air conditioner has a dual function of lowering the temperature and removing excess moisture from the air, the dehumidifier has the sole work of dehumidifying the space without cooling the air.

So if you need both cooling AND removing the humidity, the AC is the best device for you as it can address two of your comfort needs. But if you are more concerned with the high levels of water vapor in your indoor environment but do not need cooling as much, you may want to go for a dehumidifier.

There are also some situations where the air conditioner, despite its best efforts, cannot control the uniquely high amount of moisture in the air. Its cooling efficiency may also be compromised because of the intense heat combined with extraordinary humidity levels.

In this case, you may want to pair your dehumidifier with your AC and run them at the same time. The dedicated dehumidification ability of the dehumidifier will lift some of the pressure from air conditioning and prevent it from early wear and tear. The combined use of these two home devices will also give you the optimum comfort you need in the hot and damp climate.

Optimize the Dehumidification Power of Your Air Conditioning

Air conditioners do serve a dual purpose essential to comfortable and healthy indoor living. But there are further ways you can help your unit perform its functions effectively.

Properly Size Your AC Unit

As discussed earlier, properly sizing your air conditioner versus the size of your home is critical for managing humidity. 

An accurately-sized air conditioner for the space will run efficiently, not too cold or too warm, and most importantly not at all humid. This will help you save on your energy consumption and avoid moisture-related problems.

There are sizing tips available online and you may be tempted to do it yourself. But sizing your air conditioner against the measurements of your home can be tricky and will have long-lasting effects if you make a mistake. To be certain you are properly sizing your unit, ask the services of an HVAC professional to do the measuring for you. 

Choose a High-Quality Contractor

Speaking of an HVAC professional, it is very vital to employ the services of a high-quality contractor upon installation of your air conditioner. A lot of repair issues arise from hiring a substandard contractor to install your AC because they do shortcuts and ignore industry standards.

Don’t fall victim to these scams that offer cheap installation but short-change you with their services. It is best to find a trustworthy technician who will perform the installation, do the sizing, and keep up with the annual maintenance schedule of your air conditioner. This way, you will always keep your home pleasantly cool and the humidity in check.

Use A Programmable or Smart Thermostat

Older designs of thermostats are manual and can only read the temperature but not the humidity level. But modern versions of this device can help you manage the moisture level in your home with the convenience of programming it well in advance or through the use of a  smartphone.

A smart thermostat can give you the current reading of your home’s temperature and humidity level. This will enable you to manage your AC without actually being at home or having to manually update your thermostat device.

With these technological solutions, you are well on your way to a comfortable, cool but dry environment right at your very home.

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