Where To Place Dehumidifier In Basement

It’s easy to know when you need a dehumidifier. The signs will be apparent, from excess condensation on the walls to damaged wallpaper and fogging mirrors.

Sometimes you may even see mold and rot in your home. However, it would help if you never waited until rot occurs because rotting can compromise the home’s structural integrity.

It’s also relatively easy to shop for a dehumidifier. As long as you know the size of your home, all you need to do is pick a matching dehumidifier size. The same applies when shopping for a smaller dehumidifier for a single room. All you need to know is the size of the room. With that in mind, you can easily shop for a properly-sized dehumidifier.

Unfortunately, placement isn’t usually as straightforward. Granted, a dehumidifier will work regardless of the positioning. However, to get maximum value from the appliance, you need to get the placement spot on. But, of course, that’s easier said than done.

We look at placement options for basement dehumidifiers and highlight tips to help you get the most from the appliance.

Why Do You Need a Dehumidifier in the Basement?

Perhaps we should start with why you should have a dehumidifier in the first place. Sometimes people wonder why it’s necessary, especially if you don’t use the basement much.

The main reason is that relative humidity isn’t uniform in multi-story buildings – with basements often the worst affected. In addition, it can be confusing because upstairs is also usually more humid than downstairs due to the stack effect. 

The stack effect dictates that warm air will always rise and take its place at the floor level by colder air. As such, the upper floors are always warmer. Elementary physics tells us that warmer air holds more moisture than cold air. Thus the warmer air upstairs also means that upper floors are typically more humid.

The difference is usually 10% to 15%. So, if the relative humidity downstairs is 35%, expect upstairs to be 45% to 50%.

The stack effect applies to basements too. However, basements are a little unique in that they are also exposed to significant moisture leaks due to:

  1. Ground moisture: The soil around the basement contains a lot of moisture. The moisture volume is even higher in the summer when the air inside the soil traps more humidity. This moisture can leak into the basement through suction and the stack effect.
  2. Lack of ventilation: It’s great that more people are beginning to see the need to ventilate the basement. However, the majority of basements still lack ventilation or are improperly ventilated. Poor ventilation exuberates humidity issues by trapping moisture within the basement.
  3. Household appliances: In many homes and residential apartments, most moisture-producing appliances, including washers and heaters, are found in the basement. This further adds to the moisture issues in the basement.  

Remember that basement moisture issues can quickly spread to the main house. The moisture itself can creep into the first floor through capillary action and the stack effect. Worse still, the results of excess humidity, such as mold and foul odors, can also migrate or diffuse into the upper floors.

Placement Tips for Effective Dehumidification

Where you place the dehumidifier determines whether you’ll effectively extract moisture from the basement. Consider the following professional placement tips and ideas;

Size of the room 

Let’s begin with an obvious one. The size of the basement will directly impact where you place the dehumidifier. But, again, the reasoning is straightforward, i.e., smaller rooms are easier to dehumidify while larger areas take a little more effort to dehumidify evenly.

Therefore, for smaller basements, your placement options aren’t restricted very much. However, in a large area, which most basements are, it’s best to position the dehumidifier centrally so that the unit can reach every corner of the area with ease.

Auto or manual drain?

Dehumidifiers condense moisture to form liquid water collected in a special tank inside the dehumidifier unit. But, this water has to go somewhere so that the unit can condense even more moisture. As a result, nearly all dehumidifiers require that you manually empty the tank when it’s filled or have an auto-drain system to empty the unit continuously. Some even have pumps to facilitate continuous drainage.

The drainage method will also affect where you place the dehumidifier. For example, continuous drain systems are best located close enough to the sink or window, depending on the length of the drain pump.

Cord length

All dehumidifiers are electrical appliances. They depend on electricity to run a motor that drives the water removal process. As such, your dehumidifier will connect to an electrical outlet via an electrical cord. The length of the cord directly influences the location of the appliance.

The good news is that you can make this a non-issue by purchasing a longer cord separately. Just make sure to get the correct type of cord. A lower-rated electrical cord can melt, causing an unnecessary fire risk.

Air circulation 

A dehumidifier, like all other HVAC appliances, works best when there’s good air circulation. This doesn’t necessarily mean windy conditions. However, air should circulate within the basement freely. It’s the only way to ensure even the cool, dry air coming from the return vents. Uninterrupted circulation also facilitates the intake of stale air.

To this end, it’s best to place the dehumidifier in an obstruction-free area. Make sure the area is at least three feet away from large furniture or other appliances.

Away from vents and windows 

Vents and windows are entry points for outside air. During the summer, warm, moisture-laden air enters through these points. In the basement, this may also apply to the door leading upstairs.

Placing the dehumidifier in the direct path of outside air can alter the appliance’s performance. How? By interfering with the humidistat readings. Dehumidifiers, just like humidifiers, rely on built-in or wall-mounted humidistats to track humidity levels in the area. For example, suppose you place the dehumidifier directly in front of the window. In that case, the sensors may detect higher (and misleading) temperature and humidity readings, causing the dehumidifier to run faster or slower depending on the conditions outside.

It means that if there’s a breeze across the dehumidifier, the sensor may detect lower temperature and lower moisture removal rates even when it’s swelteringly hot and humid in the basement.

Other Tips and Tricks

Generally, if you can keep the five tips above in mind during dehumidifier placement, you should be able to achieve excellent moisture removal rates and experience optimal indoor air quality.

However, we must also recommend that you keep the dehumidifier away from direct sunlight as direct exposure to heat can alter humidistat readings. On the same note, keep the appliance away from dust and smoke. Excessive smoke and dirt can cause faster filter clogging and degradation. It means you’ll need to replace the filter faster. No one wants that.

You must also always place the dehumidifier away from electrical outlets, on a flat surface, and at least a few feet off the ground. Why? Because the dehumidifier collects water and this water can spill even before the tank is full. So, keep the unit away from electrical outlets and extensions on a raised, flat surface to protect yourself from the risk of electric shocks and your floor from water damage.