High humidity is just one of those things you always have to deal with when living in Florida, and it’s not something you really ever fully get used to no matter how long you live here. The hot, muggy weather is why most homes in Florida have central air conditioning: any house would quickly become extremely uncomfortable without it. While air conditioning works to remove heat from the home, it also has an effect on the humidity level in the building. At the same time, high indoor humidity also has a major impact on how well an air conditioning system works and how much energy it costs to keep a home cool and comfortable. In this article, we’ll show you why this is and what options you have for keeping your home less humid and helping make your air conditioning system more effective and more energy efficient.

The Impact of High Humidity on an AC System

It’s a simple fact that high indoor humidity has a major impact on an air conditioning system. The reason primarily has to do with the condensation that naturally occurs when an air conditioning system runs. Air conditioners cool by drawing heat out of the air and capturing it using cold refrigerant. Heat energy in the air always naturally flows into and is absorbed by any objects or surfaces that are at a lower temperature than the air. When warm, moist air comes into contact with any cooler surfaces, some of the moisture or water vapor in the air also condenses into liquid water on the surface.

No matter what the humidity level is in a building, some moisture will always condense on the evaporator coil, as the system runs since it is much colder than the air. This effect is precisely how air conditioning functions to slowly lower the humidity level in the building. The problem with high indoor humidity is that it leads to much more moisture condensing and much more water forming on the evaporator coil.

Water is a poor conductor of heat compared to air. When there is lots of water on the evaporator coil and it constantly stays quite wet, the water essentially shields or insulates the evaporator coil. This means the water creates a barrier between the coil and the warm air moving across it, which reduces the amount of heat the refrigerant can capture from the air. As a result, the AC system cools more slowly and works less effectively since it isn’t able to remove as much heat as it would if the humidity level was lower and the evaporator coil was drier. This is part of the reason why air conditioning costs are much higher and why AC systems have a shorter lifespan in cooler climates like Florida compared to drier climates.

Understanding the Effect Humidity Has on How You Perceive Temperature

Relative humidity is a measurement of how much moisture the air holds as a percentage of the maximum amount of moisture it could potentially hold. As the air temperature increases, the relative humidity decreases since warmer air can hold much more moisture than colder air. In Florida, it is common for the relative humidity to be around 60% during the hottest part of the day and then rise as high as 90% in the evening once the temperature starts to drop. However, the actual moisture content in the air doesn’t really change all that much. It’s just that the air feels more humid when the temperature is cooler since the air is closer to being fully saturated (i.e. holding as much moisture as it possibly can).

Relative humidity has a direct impact on how our bodies sense temperature and how hot you feel at any given time regardless of the air temperature. The reason has to do with the fact that our bodies sweat as a means of cooling down. When you sweat, evaporation wicks the moisture away from your body so that you feel cooler. The problem with high relative humidity is that it greatly slows down the rate at which your sweat evaporates since the air is already quite saturated and can’t hold much additional moisture. This is why you feel much hotter on an extremely humid 90-degree day than you do on a 90-degree day that is much drier and has a lower relative humidity. Similarly, even if your house always stays at 70 degrees, it will feel much warmer than that when the relative humidity inside is higher.

One major issue with high indoor humidity is that it leads many people to crank their AC up much further since their home feels much hotter than it really is. This further increases the strain on the air conditioning system since it will need to work harder and run longer to cool the home to a lower temperature, which in turn leads to rising energy costs.

How to Overcome the Impact Humidity Has on Your AC and Your Comfort

Air conditioning systems also work more effectively when the relative indoor humidity is under 60%. The problem is that on much more humid days, it can often be impossible for an AC system alone to keep the humidity level under 60%. This is why in humid places like Florida, you often also need to have some type of dehumidifier to prevent the humidity level in your home from being too high.

While portable dehumidifiers can help, they really aren’t an adequate solution in our climate. Instead, you’re always better off to install a whole-home dehumidifier. This type of unit actually works quite similarly to an air conditioner, as it has an evaporator coil and uses cold refrigerant to remove moisture from the air through condensation.

Installing a whole-home dehumidifier is a great solution that will help make your home feel cooler and more comfortable by keeping the relative humidity level lower. It will also greatly improve the effectiveness of your air conditioning system and allow it to work more energy efficiently and suffer less strain. This is because a dehumidifier will remove lots of moisture from the air so less condensation forms on the evaporator coil and the refrigerant can more effectively capture heat. This type of unit also slightly cools the air, which means that AC won’t have to run as long or work as hard since the air coming into it contains less heat.

Without a dehumidifier, many AC systems end up running almost constantly on any hot, humid days. Running a dehumidifier will obviously use additional energy. However, your overall energy costs will almost always be lower since the dehumidifier will make it so that your AC is more effective and doesn’t run nearly as much.

At J&W Heating and Air + Plumbing, we’ve been providing expert air conditioning and heating solutions to customers in the Jacksonville area since 1966. We specialize in the full range of HVAC installation, maintenance and repair services, and our team is ready to handle all of your home comfort needs. If you constantly have to deal with high indoor humidity in the summer, we can also help you upgrade your home with a whole-home dehumidifier. For more information on our range of air conditioning, heating and indoor air quality services or to schedule an appointment, contact us today.

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