Heating & Cooling

Does ecobee Use Your AC to Dehumidify? (Explained)

ecobee home thermostat lg

An ecobee Thermostat is a critical component in the automation of heating and cooling in the house. It controls the AC to provide your everyday air conditioning needs. Among the things that people usually ask about ecobee is its ability to control the AC for dehumidification. 

The ecobee can use the AC to dehumidify your house. It has an AC Overcool Max feature that facilitates the dehumidification process. To use it, you will need to activate the setting on the Thermostat’s menu. You can also connect your ecobee to a dehumidifier.

When using an ecobee Thermostat, there are loads of benefits that you are bound to achieve. Among the key ones is controlling your AC to dehumidify the house. But you must understand how to set it to achieve the desired outcome in air conditioning. 

We’ll explain everything about dehumidification using Ecobee and other critical perspectives in temperature controls. Take a look. 

Can you Control Humidity with Ecobee?

You can control humidity using ecobee. However, you need to have an ecobee with the latest features for humidity control. Hence, if your Ecobee Thermostat is outdated, it’s time you replace it. Otherwise, it will not give you the advantage of accessing humidity control and other smart features. 

The Ecobee can manage humidity levels primarily through two means. First, it can be connected to dehumidifiers. The component is successful in the management of humidity. However, with an Ecobee, you can do it even without a dehumidifier and still control the temperatures. 

How to Control Humidity with ecobee

An Ecobee thermostat features a built-in sensor that detects the changes in the surroundings and fixes the humidity accordingly. The sensor measures factors such as occupancy, house temperature, and humidity. 

Hence, control of humidity by the thermostat is facilitated by the sensors, which first detect the changes. In return, the thermostat evokes the action of the AC, which controls the humidity to the required levels. 

You might find that the Ecobee’s humidity reading is quite different from that of other humidity detecting devices in your home. The solution to the issue is a calibration of the Ecobee via a small, straightforward process. It should ideally take you less than 30 minutes to complete.

An ecobee is compatible with almost all HVAC systems. With an air conditioner, it’s possible to dehumidify the house. Therefore, the AC eliminates the necessity of a dehumidifier in humidity monitoring. The thermostat facilitates this process by enabling you to control the AC and bring humidity to the right levels. 

Most Ecobee models are compatible with dehumidifiers. However, as we will highlight later, some, such as the Ecobee lite, do not support dehumidifiers. Hence, the only way to achieve humidity control using them is temperature regulation via the AC.

Humidity levels go low as the AC pumps cool air into the room. Therefore, even without connection to a humidifier, Ecobee will lower humidity by lowering the temperatures, automatically enabling dehumidification.

How Do I Set my AC to Dehumidify?

The ecobee thermostats have an AC Overcool feature which is significant in humidity control. One of the key advantages of the feature is that you do not necessarily need to have a dehumidifier. 

Nonetheless, it’s noteworthy that this does not mean that you do not need a dehumidifier. If you’ve got one, it will work with the thermostat to control humidity better than using a dehumidifier alone. 

The feature ensures that you can achieve further dehumidifying after achieving the comfort setting of the AC. In addition to enabling cooling, it will also try to control the humidity of the house. Hence, after setting the over-cool threshold, cooling can continue until you achieve the desired humidity levels. 

Setting up the AC to dehumidify is also straightforward as you will do everything from the Ecobee’s menu. Here are the steps: 

  • First, click on the ‘Main Menu’ and select ‘Installation Settings’ from the ‘Settings’ button. Next, click on ‘Thresholds’ and select ‘AC Overcool Max.’
  • Select the level of over-cool that you would want to achieve by inputting the actual degrees that you would want the temperature to go lower by. You will have now enabled the Ecobee to lower the room temperatures in a bid also to dehumidify. 
  • Next, go to the dehumidify menu by first clicking on the ‘Main Menu.’ Select ‘Systems’ and enable dehumidification by clicking ‘Dehumidify Using AC.’ You will be prompted to choose your desired humidity level from the pop-up menu. 

How Does ecobee Dehumidify Using AC Work?

Remember that the overarching purpose of the above-discussed settings is to control humidity. Hence, if the overcooling feature can achieve the desired dehumidification, then the AC will shut off. 

However, if humidity remains high even after the overcooling threshold has been reached, cooling will continue until the set humidity level is attained. 

Also, note that an air conditioner is designed to control the house’s humidity during the cooling phase naturally. Hence, when you set the AC in cooling mode for an extended time, it will also dehumidify the air. 

Additionally, when the overcooling temperature limit is realized, the thermostat will stop the action of the blower fan for 5 minutes. If the fan remains on, it may evaporate the moisture in the AC back into the house. Consequently, the humidity inside the house will increase. 

Therefore, the Ecobee thermostat shuts off the fan to ensure that no action in the AC will revert the dehumidifying process. 

How to Best Control Humidity Levels with ecobee Lite?

Achieving humidity control even while using Ecobee Lite is possible. However, you need some modifications and accompaniments to the Ecobee Lite to make it fit for humidity control. While it won’t support a humidifier or dehumidifier, you can still use it to control the AC. Nonetheless, you will have to connect it to external sensors. 

You might find that the price of the Ecobee models in the market is beyond your reach and thus opt for a cheaper version. For instance, Ecobee 3 will be less expensive than Ecobee 3 lite. However, the lite property means that some key features of the other model are absent.  

Among the things you’re going to miss out on when using lite is that it lacks an inbuilt Amazon Alexa. Still, you can control the thermostat using other Alexa devices. It also does not have an inbuilt smart sensor. However, it supports external sensors. 

Lastly, it will not effectively control humidity like the other Ecobee versions since it does not support humidifiers or dehumidifiers. However, you can still use it to control the AC. We earlier highlighted that an AC is significant in humidity control. 

Thus even without humidifier and dehumidifier support, it’ll still control humidity via the AC. 

What are the advantages of ecobee Lite?

We have highlighted the key shortfalls of Ecobee lite. But does that mean that there are no upsides to the Ecobee model? There are several advantages of using the lite version; hence you should not be worried about settling for it. 

Here are some of them: 

  • It has a simple build-in schedule. Thus, you won’t take too much time to understand how to use the device’s various features. 
  • You can also effortlessly override the existing schedule by using the ‘Quick Change’ option on the menu. Thus, you will not need to navigate through the menu to enter a new setting. 
  • It also works effectively with common automation systems such as Amazon Alexa. 
  • Like other Ecobee versions, the Ecobee lite menu is accessible from the device itself, app, or website. Thus, you can control the device even when you are not in the house from your mobile device. 
  • You also don’t necessarily have to use a C-wire while using the lite version, as it will still function without it. 

Using Remote Sensors with Ecobee Lite

An Ecobee 3 lite thermostat will be compatible with room sensors, which is essential in humidity control. It lacks an inbuilt sensor and thus needs an external sensor for the detection of the surrounding temperatures. 

Ecobee 3 and Ecobee 4 have inbuilt sensors, which in addition to measuring temperature and occupy, they’ll also detect humidity. For the light version, humidity detection is not possible; hence you’ll have to connect it to a remote sensor. 

The remote sensors will be in three primary states:

  1. Monitoring Mode. During this phase, the Ecobee Lite will only be checking the space and not taking part in temperature control.
  2. Control Participating Mode. The remote sensor is actively involved in temperature control during this phase when you activate the ‘Comfort Setting’ on your Ecobee.
  3. Control, Non-Participating Mode. It is actively involved in the Ecobee’s temperature control but in a different ‘Comfort Setting.’

Does Turning on AC reduce Humidity?

Turning on the AC will significantly be controlling the humidity levels in your house. To achieve this, you need to set the AC on cooling mode. An Ecobee thermostat is great in detecting temperature changes in the house and switching on the AC when the air heats up beyond a particular level. 

Nonetheless, you must ensure that your AC is in working condition to enable humidity control. Here are the key things that you need to do to improve the performance of your AC: 

Clean the Evaporator Coil 

An HVAC evaporator coil is bound to collect dirt and dust from the surrounding. Note that the particulate matter will hamper its functionality, especially in heat regulation. Also, remember that temperature control is also directly linked to humidity control. 

Thus, regular cleaning of the evaporator coils will go a long way in improving their effectiveness in temperature control. You also need to ensure that the air filters are clean. The filters’ primary role is to clean the air that gets into the AC unit. Accumulation of dirt on its surface will inhibit air filtration. 

Dirt on the air filters will also be blown to the house by the blower fan. You’ll thus be inhaling dusty hair, which is unhealthy. When choosing air filters, you must also consider factors such as the level of filtration that you want to achieve. Also, if you have allergies, install air filters that trap allergens like pollen. 

Adjust the Fan Speed

Ideally, the optimum fan speed for reducing humidity in the house is 350 CFM per ton. Since most fans can run faster than that, many people may be compelled to set it up at higher speeds. However, it will only damage the attempts to bring the humidity levels down. 

At low fan speeds, the indoor evaporator coil will cool faster. Hence, it will be effective in moisture removal and lowering the room’s temperatures. The best choice for lowering the temperatures in the house is an air conditioner whose speed can be controlled. 

Install a Thermal Expansion Valve

Thermal expansion valves (TXV) help maximize the operation of the evaporator coil. When the evaporator coil is in top condition, it’ll be easier and faster to cool the air and dehumidify the house. 

Check the Refrigerant Levels

The refrigerant is very pertinent in the working of the evaporator coil. If the levels of the refrigerant go lower than the optimal, the evaporator coils will freeze. It will, as a result, inhibit effective temperature control. 

Also, note that repairing the evaporator coils will be in the offing if the refrigerant levels are low. Thus, you must always ensure that the refrigerant is at the required limits. Otherwise, your AC will struggle, and you will also be prompted to spend on repairs. 

Use the Right HVAC Size

It might seem like a largely sized HVAC is better in humidity control as it will cool the room in short cycles. However, this is not the case. A smaller HVAC is more effective as lowering the humidity needs extensive running of the AC. 

Therefore, you’ll find that a large HVAC will be too fast to lower the room’s temperatures but struggles to lower the humidity. If you have had a case where the Ecobee indicates that the temperatures are low, but in reality, the humidity is still high, your HVAC is larger than necessary.  

Install Dehumidifiers 

An AC may sometimes fail you in temperature regulation, especially if it is poorly sized. Having a dehumidifier in the house will go a long way in bailing the AC out in such a case. A dehumidifier is designed to lower the humidity and thus will perfect make up for the AC’s failings. 

Final Thoughts

Ecobee will use the AC to dehumidify during the cooling cycles. However, you will need to activate the overcooling feature on the Ecobee first. It is easy to set up using the steps that we have highlighted above. 

You can still lower the humidity even without a dehumidifier as long as your AC is working. As the AC cools the air, it also absorbs moisture from the surrounding. For optimal dehumidifying, it’s imperative to have a dehumidifier and the AC in top condition. 

We have explained how to ensure that the AC is ready to dehumidify. Each of the tips is important in the operation of the HVAC. Hence, apply them, and your AC will successfully dehumidify your house to the required level. 


Hubert Miles | Licensed Home Inspector, CMI, CPI

Hubert Miles is a licensed home inspector (RBI# 2556) with more than two decades of experience in inspection and construction. Since 2008, he has been serving South Carolina through his company, Patriot Home Inspections LLC. As a Certified Master Inspector, Hubert is dedicated to providing his expertise in home inspections, repairs, maintenance, and DIY projects.