What Is A Dehumidifier


Have you ever had that feeling that you are heating up, the air you are breathing is heavy and very warm? You are in the comfort of your own home but you are not comfortable?

Or even your allergies are flaring up because the air is too moist. That usually means the space you are in has excess humidity. You may have to get a dehumidifier to fix that problem.

A dehumidifier removes excess moisture from the air in your house. A dehumidifier will improve breathing. If you or a member of your family are asthma sufferers or have allergies you’ll breathe better.

A dehumidifier improves health and comfort. It removes musty odor, and prevents mildew from developing by removing water from the air. 

Dehumidifiers work for both household or commercial purposes. [1]

Let’s dig a little deeper into dehumidifiers to see if this is what you need.

Humidity & It's Effects
Humidity & It's Effects

Humidity And Its Effects

What is humidity, and why does indoor humidity matter?

Humidity is the concentration of water vapor in the air, this can either be too low or too high. In this case, I am focusing on the high levels that leave you feeling hot and sluggish.

When the humidity in your home or office is too high, it makes things unpleasant, but it can also damage property. In my case, it was my entire shoe collection. High levels of humidity create excess moisture and condensation. This can lead to mold or rot. [2]

Why do indoor environments have humidity?

Several factors determine the presence of humidity and its levels in indoor environments. Two major contributors to humidity indoors are moisture and efficiency of ventilation.

You may live in a place that has wet spaces. For example, my basement as a child had this strong musty smell that I only made sense of years later.

Ventilation is a comfort factor. Air changes allow moisture to evaporate. 

Moisture and limited ventilation can lead to high amounts of humidity indoors.

Warm air will dry objects. Think of a hair dryer. So, by turning up the heating in a room, the levels of relative humidity will fall. But this is not always a possible option. It means having the heating cranked up, leading to eye-watering energy costs.

Indoor Humidity

Tasks like washing, laundry, bathing, cooking, and even breathing create a humid environment. By minimizing the moisture content and letting it escape, we can reduce humidity.

Adequate ventilation helps reduce humidity. Ventilation is hard to achieve in rooms with no windows like the basement or bathrooms.

Signs you need a dehumidifier

When humidity levels remain high for extended periods, there are some signs one can see. Once relative humidity hovers above 60%, mold spots and mildew will start to grow.

High moisture levels can cause rot, property damage, affect living spaces and health. It is at this point you should start considering getting a dehumidifier.

Signs of high humidity in your home include:

  • Visible water stains on the walls or ceilings 
  • Rooms with high humidity, inadequate ventilation or no ventilation 
  • When you see condensation on windows in certain areas, such as kitchens and bathrooms 
  • The presence of mold spores growing on the walls and other areas, such as the bathtub or shower 
  • Must or mildew smells 
  • If you live in a place that smells damp – like an apartment building.
Side Effects Of Excessive Humidity
Side Effects Of Excessive Humidity

Side-Effects Of Excessive Humidity

What are the side effects of humidity?

Mold growth and mildew growth

Microscopic fungi are all around us. They find the perfect conditions in our homes’ damp parts to settle on surfaces and grow. Next thing, you have fuzzy hairy things growing everywhere.

Mildew refers to the white or grey coating on surfaces. Usually, you find it on shower curtains, windowsills, or tiles. The color of the mold is black or dark green.

Mold can penetrate deeper into construction materials. Mold can also cause allergies, health issues, and asthma.

Suppose you don’t interrupt the mold growth immediately. The fungus digests and destroys materials it lives on. This is what happened with my shoes.

This may mean that you have to throw away things such as soft furnishings, books, carpets, or soft toys.

Mold can also damage the structural integrity of buildings. In extreme cases, it compromises ceilings, walls, and more.

Furniture, boards, and furnishings rotting

High humidity; meaning, excess moisture damages wood. It produces stains and growth or causes more extreme decay. We had a year when we had a burst pipe in the den. After cleaning up the mess, we didn’t address the dampness left behind.

This had a knock-on effect affecting all furniture near our den walls. We found out water had done some permanent harm.

Our hardwood floors, window frames, and furniture were damaged. These are the types of problems you can experience when excess moisture goes on for a long time.

Walls and brickwork weakened

Our home’s walls may have vapor barriers. Barriers are there to prevent moist air from entering. But these are never ideal.

Moisture tends to condense in foundation materials, crawl rooms, and basements. This usually happens when the weather is warmer, leading to structural problems. 

Materials expand or contract whenever the moisture content in them is fluctuating. High humidity may also lead to cracks, which could need costly repairs. This is the last thing you need to deal with as a property owner, as repair bills can go up the roof. [3]

The ideal humidity for an indoor environment

I have done some research to find out the ideal humidity we should maintain in most indoor spaces.

Humidity of 70% or higher can cause severe damage. The Building Science Corporation and the Health and Safety Executive recommends relative humidity indoors be 40- 60% thresholds.

Dehumidifier Benefits
Dehumidifier Benefits

Dehumidifier Needs And Benefits

When do you need a dehumidifier?

If you are suffering from allergies related to dampness, you may need a dehumidifier. If you value your comfort, like to sleep well, and feel at ease, you may need a dehumidifier.

What does a dehumidifier do?

A dehumidifier sucks in air from your room, takes the moisture out of it, and then blows it back out into the room again. Pretty much the same way a vacuum cleaner works. Instead of sucking up dust, it collects the moisture. Water then drips through into a collection tank. [4]

Benefits of dehumidifiers

1. Preventing Mold

I can testify that any homeowner’s worst nightmare is mold.  Mold destroys surfaces by causing natural materials to break down. If left unchecked, it spreads.

Mold can become hazardous, placing the health of your entire household at risk. As I have pointed out, the perfect breeding ground for mold to thrive in damp air above 50+ percent humidity.

A dehumidifier will reduce the excess moisture while preventing new mold growth. If anyone in your home suffers from asthma attacks or mold is developing, you need a dehumidifier.

2. Air Quality Improvement

The air quality in your home depends on the number of pollutants you inhale and humidity. The most powerful way to rid the air of hazardous compounds is an air purifier. 

A dehumidifier also plays an essential role in improving your indoor air moisture. Consider a combination air purifier dehumidifier.

3. Helps Remove Dust Mites

Dehumidifiers also remove dust mites in the air. Dust mites might be responsible for why you’ve been wheezing so much lately. Household dust mites are the common causes causing a flare-up of allergies and asthma.

Mites thrive in wet, humid climates. Dehumidifiers help maintain the best level of humidity in your home. In turn, reducing the atmosphere in which dust mites survive.

4. Protects Your Home

Dehumidifiers help protect from the damage to the structural integrity of your home. Over time, the wood in your house, including support beams, can warp, crack or break due to excess moisture. Metal fittings are likely to start rusting.

A dehumidifier is a simple way to stop the gradual degradation of your home. This appliance provides a healthy living atmosphere for your family. [5]

Dehumidifiers for allergies

Mildew will cause the same symptoms as outdoor pollen if you suffer from allergies. There are also mold allergies. This is where a dehumidifier works, drawing out moisture in your air.

Dehumidifiers keep your humidity under control, preventing mildew from forming. I use my dehumidifier to maintain the humidity level between 45 and 50 percent. Dehumidifiers remove and prevent mold indoors. [6]

Dehumidifiers for asthma

 A dehumidifier can run year-round or only during a specific season. I live in an area that is humid in summer, and removing excess moisture improves asthma symptoms.
When there’s moisture in the air, I found that it gets heavier and challenging for my children to breathe . People who have asthma can find high-humidity environments difficult.
The effort to breathe in and out of the lungs is easier when you use a dehumidifier. The air is cooler and more pleasant, and the mugginess disappears. [7]

Impact of dehumidifiers on environment

Dehumidifiers alter the air in our homes. They also create a cooler, pleasant environment. When I cut down on mold and dust particles; I also got rid of silverfish, cockroaches, and spiders.
Dehumidifier Types
Dehumidifier Types

Types Of Dehumidifiers

Classifying dehumidifiers into four groups [8]

There are four types of dehumidifiers

1. Heat Pump Dehumidifier.

This type consists of a fan, heat pump, and heat exchange coils to remove moisture from the air. The fan forces the air past the heat exchange coils, which are extremely cold. And moisture present in the air condenses into liquid water and collects in a reservoir.
2. Dehumidifying Ventilator.

This humidifier is more straightforward as it works by using an exhaust fan to expel air outside. It uses a sensor triggered by either a timer or closing the door, and the exhaust fan kicks in.  This type of dehumidifier is most often used in crawl spaces, basements, and attics.

3. Chemical Absorbent Dehumidifier.

It is also known as a desiccant dehumidifier. It consists of hydrophilic materials. Silica gel draws water from the atmosphere. Most residential absorbent units contain single-use desiccant-type cartridges, gel, and powder.

4. Homemade dehumidifier.

For those of you that are hands-on, there are many ways to fabricate and build your dehumidifier. While I don’t recommend it as a permanent solution, it might help in the short term. Charcoal, road salt, and de-icing salt are often used to make homemade dehumidifiers.

Types of dehumidifiers

The dehumidifiers I will be looking at work in one of two ways, refrigeration and absorption. Below we will look at how they go around removing water from the air in different ways.

Refrigeration dehumidifiers

These are the most popular kinds of dehumidifiers as they are refrigeration based. They are very efficient. These extract moisture from the air by condensing it on a metal plate. This process cools the air.

Working of refrigeration humidifiers

This dehumidifier uses pretty much the exact mechanism as your home refrigerator. A cold metal plate on which moisture from the air condenses cools the air that comes in contact.

A fan draws the room air over to the cool metal plate(s), and the moisture condenses as it comes in contact with the plate. The condensed water droplets that form drip into a water tank in the dehumidifier.

When the relative humidity in the room goes down to normal levels, the unit will then turn to standby.

Refrigerant dehumidifiers are most effective at typical room temperatures. But I have noticed that their performance declines when conditions are cooler. This decline is due to ice crystals forming on the metal cooling plates (coils).

I have noted that once the temperature falls below 65°F/18°C, there is a fall in efficiency. After this point, you need a higher-performing unit which tends to push up the price.

So if you need a dehumidifier to use in a room with low temperatures, this may not be the best option to pick.

Adsorption dehumidifiers

An adsorption dehumidifier uses a desiccant to absorb water from the air. A desiccant is a water-absorbing compound such as silica gel.

Working of adsorption dehumidifiers

A wheel composed of the desiccant turns through the incoming air stream. Incoming air absorbs moisture using the desiccant. A proportion of the wheel passes through a stream of warm air during the rotating period. It “reactivates” the desiccant moving away from the moisture.

Condensed water collects in a storage tank or drains out via a drainage hose. The water collected is measured in pints. This dehumidifier unit is generally smaller and lighter than refrigerant type.

Adsorption dehumidifier can function at much lower temperatures than a refrigerant unit. For those of us who live in cold areas, this is the ideal unit to have.

If your conditions are like mine, you might want to consider this type of dehumidifier. I must note that adsorption dehumidifiers are high energy users.

You are usually consuming 600-800 watts of energy per hour. The technology is becoming more reliable. Manufacturers are working on improving energy efficiency. [9]

Where Can A Dehumidifier Be Used
Where Can A Dehumidifier Be Used

Where Can A Dehumidifier Be Used?

Dehumidifier needs and uses are wide-ranging. They are dependent on your needs, climate conditions, and type of building or room. The requirements differ across the board. From office blocks, industrial installations and residential use.

A wide range of situations include:

Excessive body perspiration build-up. Sweat cannot evaporate in moisture-saturated air due to the sheer numbers of occupancy.

Condensation dripping from cold-water pipes in industrial units

Warping and sticking of furniture and doors

Mold and mildew build-up on fabrics, books, and furnishings in an apartment

Infestation of clothes by moths, fleas, cockroaches, woodlice, millipedes, and dust mites. These insects thrive in damp conditions.

Damp locations examples include:

  • Basements,
  • Crawl Spaces,
  • Kitchens,
  • Dens,
  • Bedrooms,
  • Bathrooms,
  • Indoor Pool Areas,
  • Warehouses,
  • Workshops.

I always recommend placing a dehumidifier on the floor in a room. It has to have the lowest temperature (the coldest floor) in the house. This can be either upstairs or downstairs. So getting a portable dehumidifiers would be best if it needs to be moved.

The kitchen, laundry room, bathrooms tend to contain the most water. These areas are high-level humidity locations in most homes.

Ensure that you place your unit in an area with the best possible airflow.  The dehumidifier should be able to quickly draw in the air and expel the hot, dry air with ease. Make sure there are no obstacles that could obstruct airflow.

Some dehumidifiers’ are noisy. Be sure to place them away from areas that need silence, such as office spaces and bedrooms.

Use of dehumidifiers in offices

Using dehumidifiers in offices relies on many variables. Consider the room’s size and how many dehumidifiers you need. If only one dehumidifier is required, the best location is a central place.

There are more factors, such as room height and airflow. You may not be able to wall mount your dehumidifier in a room that has a low ceiling, so you might need to get a stand for it.

I always recommend floor placement or under a table in most cases. I placed my dehumidifiers on a plastic crate so it’s easier for water to drain way into the hose. Be sure to place the dehumidifier away from the wall. Consider the manufacturer’s recommended distance to prevent the machine from “choking.”

Pick a spot that helps with airflow. Position the unit away from direct flow from an air conditioner or heater. Every dehumidifier has different wall spacing guidelines. So when in doubt, always check the owner’s manual.

Final thoughts

Humidity issues in your home can be a real nightmare.  Your health and comfort are affected. Your safe and clean property is also a concern. Sometimes humidity only occurs during some months of the year or it can be all year round.

I recommend getting a dehumidifier for its health and comfort benefits. Dehumidifiers make a world of difference. Keep yourself “at ease”. Save yourself a lot of money on medical bills and home repairs. Protect your valuables and loved ones.