How Does a Humidistat Work with Air Conditioning | Expert Guide


Articles, products, and services offered on this site are for informational purposes only. We are part of the Amazon Services LLC Associates Program, an affiliate advertising program. is compensated for sales resulting from links on our website.

Please review our disclaimer before acting based on anything you read or see.

Well! We all know that water is the essence of life, indeed. But it is a fact that “excess of everything is harmful.” The same goes for water. Yes, if the water is in excess in the environment, it gets humid, and humidity can damage and create a mess around home or business. However, as mostly, science has come to our rescue and presented us with an electronic machine called Humidistat. Yes, a humidistat helps regulate the moisture level to prevent mold, corrosion, health risks, and many more. In this discussion, we will give you essential tips for how does a humidistat work with air conditioning?

What is Humidistat?

  • A humidistat can be defined as the humidity control system that operates in the home heating or cooling device and controls a specific humidity level in the house by automatically adjusting the excessive humidity levels known as a humidistat. The humidistat transfer signals to the humidifier to prevent the water supply from turning on or off in the central air conditioning system once you attain the desired humidity level. 
  • Setting humidistat maintains a comfort level in your house and prevents corrosion and mildew issues in humid areas.
  • If humidity exists to no small extent inside your home, there is an increased risk of fungi, bacteria viruses, mildew, and dust mite infections. Other issues include the peeling of wallpaper and paints, window trims, furniture damage, and collected condensation on windows due to the excessive humidity levels. 
  • However, typically if the humidity level is below 68%, the mold and mildew cannot grow at this level. Moreover, excess moisture is not suitable for recreational vehicles. That is why the dry kits for RVs, storing boats, and automobiles are suggested, where there is no option available.
  • Humidistat is also known as hygrostat and is analogous to the thermostat, which means humidistat thermostat combination, which helps attain comfortable temperature and moisture damage solutions. 
  • Humidistat is not only a part of the humidity control system in houses. However, it is also necessary for other electric appliances like refrigerators, climate control warehouses or greenhouses, and microwave ovens. 
  • Check the freon in a home air conditioner regularly.

Working of a Humidistat in Air Conditioners

Your central air conditioning systems regulate the indoor environment in especially in two ways.

  • It cools your homes by regulating the humidity level and removing an excess amount of moisture in the air inside your homes.
  • It heats your homes with the heating coil by working in contrast to a heat pump type unit.
  • Air conditions of every type have a built-in thermostat to control these type of functions, and in some air conditions, there is a humidistat is also there; if you want to get the best results, you should set the humidity level on Humidistat up to 58%
  • When your air conditioner is working warm in your homes, the interior air passes through a metal coil, which is cold and thus makes it air cool.
  • When air passes through the coil, moisture present in the air also makes the cold coil condense, drips into a pan, and is drained out of the interior.
  • The removal of moisture depends on the size of the air conditioner as well. This means that the air conditioner’s correct size will help remove the proper amount of moisture, as it cools the inside air to keep the outside environment comfortable.
  • To attain the comfort level of humidity, you can set your Humidistat up to 60%.
  • If you are a seasonal resident of that area, you can save energy and money if you set your air conditioner at a high-temperature level when you are away from it.
  • Humidistat in Air Conditioners might affect due to lack of caring and the main problem is Geckos. Always keep them out from your AC.
How Does a Humidistat Work with Air Conditioning
Statistics Shows that
  • Majority of people like the indoor temperature range between 74 to 76 degrees for their air conditioners, which can maintain your humidity level below 60 %, which comes in your comfort zone.
  • But when your air conditioner is working less efficiently, there can be a possibility that there is more humidity content inside your home and leads to mold formation.
  • The specific humidity level at which mold can quickly form is below 30% and above 60%; if you are living in tropical and humid areas and have Humidistat in your home appliances, you can quickly deal with the issue of mold formation and can identify.
  • When Humidistat starts working in your air conditioning systems, it will operate at average temperature, thus cools and removes moisture in the indoor environment in a better way.
  • When no people live in your homes, the temperature inside the room will rise and fall outside the house, and your thermostat will maintain the proper humidity level.
  • The reason is that the people perspiring the moisture level, showers are being taken, and exterior doors are open, so humidity level will automatically rise but slowly.
  • Alternatively, the humidity level will not fall with the exterior environment and increase to the danger zone, unlike the temperature.
  • If you set the interior temperature at 80 degrees, your home will be in a dangerous zone suitable for mold growth.
One Study shows that;

Craig Muccio of the Florida Power and Light suggests a suitable setting of 58% when Humidistat can be off 10 %. However, mildew and mold should not form where a humidity range is below 68%.

  • When the Humidistat is attached to the system, it should set on suitable reading when you notice the interior humidity level increases to the extent that mold formation is easy. Humidistats should be off at the level of 10 to 20 % in a routine.
  • In most cases, professionals recommended humidistat settings for the device’s primary regulation, and the thermostat operates the secondary function for air conditions.
  • When you are in the home, you should set the thermostat set to on position, so it should not override when it reaches a particular humidity level.
  • On the other hand, when you are away, you can set the thermostat faster than the normal at which you feel comfortable.
  • Suppose you have a problem with humidity level readings, especially in cool climates. In that case, you should provide warm moisture to some extent into the air, and if it is cold outside, thus leads to condensation formation on the walls.
  • In the warm climatic areas, the problem of inaccurate humidity readings comes when you set it to the level of 60% and do not permit the HAVC system to operate until it can achieve the level of 60% humidity.
  • It works well if you don’t forget that the system should be off as possible up to 20%, which provides up to 80 % humidity.

Adjustment of Humidistat

It is essential to note the humidistat fan settings precisely like if the outdoor temperature is near 10 F, set the Humidistat at 20 %, and if the weather is near 0 F, set it to 25 %. If the outdoor temperature is 10 F, set it to 30 %, and if the outdoor temperature is 20 F, set it to 35 %. It is best to make a humidistat setting chart to make it okay for working.


  • It works with both cooling and heating systems.
  • There is no need for refilling buckets of water and easy to maintain.
  • No adjustment of the thermostat is required, as it is a function of the Humidistat.
  • It saves your electricity costs; reducing energy costs will significantly differ in the savings level could not be attained at 20%.
  • It is helpful for the ill effects due to higher humidity levels.
  • Dry air can cause respiratory problems, chapped lips, dry skin, sore throat, and allergy problems, and you can easily avoid these problems by Humidistat.
  • The alternate metal conductors can predict the quantity of electrical resistance by taking into account the relative Humidistat.
Air conditioner humidity setting

How Does a Humidistat Work with Air Conditioning: FAQs

How is humidity controlled with AC System?

The majority of HAVC systems are capable of regulating moister levels. The HAVC System has an evaporator coil that condenses water vapour from the air, similar to the condensation outside the glass. The liquid condenses the air and thus makes your home less humid.

What should my Humidistat be set at in summer?

The humidistat setting in summer should be between 35 to 45 % in summer.

How do I know if my Humidistat is working?

Turn Humidistat to a shallow setting or to off. The millimeter should register no voltage and then turn the Humidistat to a high level, like at 80 percent. When you hear a click sound, the millimeter should write about 24 volts if it works properly.


To end the topic of how Humidistat works with air conditioningit is evident from the above information that Humidistat plays a vital role in regulating your homes’ humidity levels. But also, they can do more harm than good. For this purpose, the majority of HAVC companies have recommended thermostats and regulators. So if you want to let them work properly and more efficiently, you should know all the available devices’ ins and outs with much care and interest.

Comments are closed.