How to Dehumidify a Room

The enemy of most clothes, leather goods and generally anything that can be at risk of mildew or mold forming is high humidity in the house. High humidity causes a room or the whole house to have a clammy damp atmosphere which is generally bad for your health and the health of your family.

We are lucky that there are ways of decreasing or eliminating humidity in a house, especially near rivers and the sea. Any dwellings close by water sources are a cause for high humidity, which can invade the house. Air circulation is one method, and good circulation is recommended; however, installing a dehumidifier is a more effective way to dehumidify the whole house.

How To Dehumidify A Room?

While some relatively low-cost methods to dehumidify a room, some methods take a little more effort to achieve good results. A lot depends on the size and also the percentage of relative humidity measured. Somewhere between 30% – 50% relative humidity (RH) is satisfactory, especially for a bedroom. Anything over that is unhealthy.

Looking at various methods, we have a few tried and tested ways that can effectively dehumidify a room.

Rock Salt

A hygroscopic material is needed to absorb water or, in this case, dampness. Such a natural element is rock salt. While rock salt is very soluble in water, it is also a good absorption material as well. It is found in dried-up seabeds, such as the Great Salt Lake in Utah; however, we are talking about mined rock salt, which is specially prepared. It’s a natural salt which is a non-toxic substance from which crystals are extracted. This is the rock salt we can buy from many places, and it is an affordable product.

It is easy to make a rock salt dehumidifier, especially if you are a DIY person. You will need two stackable containers, so read on, and we’ll show you how to do it.

Drill, Drill, Drill

Start drilling holes in the top of the top container and possibly some round the sides.

Add the Salt

Now place the top container into the bottom one; add the salt. Any amount will do, and there is no set amount, but about a quarter of the container will suffice.

Place Strategically

Place the containers, now your homemade dehumidifier, in a place where it can collect water, especially a damp spot. If you happen to have a fan, direct some extra air at the containers to help the process. Now the result is quite amazing. The moist air being trapped or blown at the top container will pass through the salt. This will absorb any moisture and deposit it in the bottom container.

There are pros and cons to this homemade dehumidifier


It’s affordable

Readily available

Easy DIY exercise


Only useful for short term use as the salt in the containers will need replacing, and the bottom container will need to be emptied.


DampRid is a readily available product that can effectively remove moisture from a small space. It will happily remove moisture from the bedroom, a greenhouse or an RV. This product uses calcium chloride, which will remove moisture from the air. Once it absorbs moisture, it will solidify into a block. These crystals are whitish in color and pick up a rusty-looking tinge over a period.

DampRid is an affordable product at around $10. Many homeowners like to use this method as it is a user-friendly product that leaves no deposit.


Similar in most respects to DampRid, Dri-Z-Air is a similar product one can buy. Basically, calcium chloride crystals are non-toxic and are an effective moisture remover by absorption. Dri-Z-Air comes in bags as crystals, unlike hanging absorption and hanging type sachets. Dri-Z-Air does offer a recycled plastic pot complete with a 13-ounce bag of crystals to begin with. Similar to our homemade moisture remover, Dri-Z-Air comes in a double container, a top and a bottom section. The same idea applies to this arrangement. The bottom part collects the water that is absorbed by the crystals in the top. These crystals will gradually disappear as they absorb moisture, and once they have all gone, it will be time to buy some more. You can also make your own container of plastic similar to our first mentioned DIY container. Here’s how to do this:

Take a plastic colander or substantial strainer and line it with an ABS or vinyl soft sheet or screening. Place the crystals in there and a plastic bowl underneath to catch the now dissolving crystals.

Dri-Z-Air is easy to use and also easy to dispose of the liquefied product. Simply pour it down a toilet or drain. As the crystals are non-toxic, they are quite safe as the resultant liquid is simply brine and can harm the environment or drain.


It is non-toxic


Easy to use as described


It does require refilling once the crystals have gone.

Standard Baking Soda

If you have an emergency, simply open up the pantry and take a tin of baking out. Yes, this is also a good moisture absorber and is usually right there in the kitchen or pantry.

This product is affordable. Take a bowl, pour some baking soda in it, and place it in a damp place to absorb the moisture. This is a good trick, especially if you have a situation where mold or mildew is forming, which can be very destructive to clothes and shoes. Don’t forget to stir it around occasionally, as this ensures it collects all the moisture.

Take Note

Baking Powder is not as effective as rock salt or calcium chloride, but it will suffice when needed. This is especially true for smaller areas such as cupboards or clothes storage areas where there is dampness. You can place many containers around these areas, especially near damp patches on walls that will harm the contents of your cupboard.

Another really good thing about baking powder is that it will absorb odors. Where you have dampness, you will find a musty smell, and the baking soda will take care of this as well.


Most likely in your kitchen pantry already


It is also non-toxic


It will only work for smaller areas

It is not a dehumidifier

A Dehumidifier Unit

Should you, unfortunately, have a damp home, the best way to effectively extract the dampness from the air is with a dehumidifier unit. A dehumidifier unit will consist of a small fan and a coil of tubing in which a refrigerant is circulated employing a compressor. Any moisture in the air drawn by the fan will condense on the tubes, dripping the moisture into the container below. All you have to do is empty the container now and then.

Unlike the natural methods that can be used, as previously mentioned, this dehumidifier requires power. It needs to be plugged into your utility socket to power the compressor and the fan. A larger area in the house can be effectively dehumidified.


It is designed to dehumidify a room

Very effective in larger rooms

You can control the humidity


It uses a significant amount of electricity


Should you have a ceiling fan in the room, you will find they are effective air distributors. A standing fan will have the same effect. However, a reversible ceiling fan will blow and circulate the air much faster. Air is drawn up and replaced with cooler air that is drawn from underneath. This makes for an excellent air circulator, thereby acting as a dehumidifier. Used together with a commercial unit, you will be able to dehumidify a room quickly.


Easy to use

Improves the air circulation within a room


Fans can be noisy

Uses electricity

Air Conditioning

Air conditioners will dehumidify a room while cooling it at the same time. It also draws air over a cooled coil, expelling the dry air into the room. The difference here is that the dehumidifier will expel the warm air into the room while an air conditioner will disperse it outside. This is why most units are fitted in a window or through the wall. This option usually has to be installed by a serviceman. It can effectively help to dehumidify the room.

Some air conditioner units are equipped with a dehumidifier option, it removes the necessity of running both units simultaneously.


Very effective at dehumidifying a room

Adds a cooling function as well


Uses a significant amount of electricity.

Space Heater

While humidity is most common in summer, we can see humidity in winter months as well. For example, cooking, boiling water, etc., can add to the humidity in a home. A space heater is an excellent source of dry heat and will remove a lot of moisture.


Effective during the winter months

The added warmth is provided by a space heater


They can be difficult to use around small children

They consume electricity which is added to your power bill

What causes humidity in a home

One of the main reasons for humidity in a home is a lack of clean circulating air. There are also many other factors to be considered. Here is a list of some of these.

During winter, windows are usually closed or barely open. Thus, no fresh air is circulating. It is important to have a breeze blowing through the house to exchange the bad, stale air for a fresh outdoor breeze.

Normal household appliances are also a problem, such as washers. These can cause moisture to escape into the house, especially the type that heats the water. The best remedy here is a small fan near a window to bring in some much-needed clean air. A great idea is to measure the humidity in your house with a hygrometer.

Water Damage

Old plumbing is often seen with small leaks and leaks within the house walls. This is definitely a cause of dampness. So, if any leaks are present, the first choice is to have them fixed. Mold and mildew form on walls with leaky pipes, which also permeates the air. It is best to call in your professional plumber for a solution to this problem.

Indoor Greenery

Those lovely plants which adorn windowsills and lounges for decorative purposes also give off a certain amount of humidity. All plants require water and are in warm conditions, especially with winter heaters going.

A solution here is to move these plants outside or to a balcony. Make sure they are sheltered from harsh winter conditions. NASA recommends that a plant can be placed every 100 square feet. Take note that certain plants absorb and release chemicals and other pollutants together with certain VOC’s. It may be an idea to rethink the humidity present in the house regarding indoor plants.


A fireplace is a welcome addition to a home and is a cheap way to warm the whole house. Fires, of course, require firewood. This wood, normally stored indoors, absorbs moisture, and then gives it off when warm. You might consider storing your firewood outside but protected from those snowy days, as this is when a fire is welcome.

Signs of Humidity in the House

A certain amount of RH is not always bad. Very dry air is also a cause of some problems such as dry throats and other small medical problems. You need a balance of humidity to enjoy a comfortable environment.


When gazing out of a window on a chilly morning, you may find condensation is forming on the glass, which runs down to the beading. If there is any water on the beading, it is a sure sign of too much humidity in the house.

High humidity inside will cause mold or mildew, which forms on walls, ceilings, and even within your cupboards. It is best to call in a professional for a report to assess the degree of moisture. He will do some tests using an instrument to measure the amount of humidity present. Mold on walls is the last thing anyone wants. It will not always clean off, which necessitates re-painting.

Musty Odor

If high humidity is present in the house, it can cause a musty odor, especially in basements and garages. A musty odor is possibly a forerunner of mold. So carefully check that there is no odor present.


High humidity will cause dampness which can affect your health, especially if you suffer from asthma. Respiratory issues can also suffer, such as coughing or wheezing. The recommended humidity level is around 60%. Check

your humidity level; it is good to know what it is.

How to measure Humidity

As mentioned above, there are several signs to note and check, and it is worthwhile to measure the humidity. The best way to measure the humidity is with a hygrometer. There are several options at your local hardware store that can be obtained to do this. There is also a thermometer in this instrument, which is handy to have as well. All you need to do is place the tool in a room and leave it for a while. It will show you the RH.

Air conditional engineers and ceiling installers use a whirling hygrometer which is a similar instrument with a handle. One thermometer bulb has a wick feeding into a small water container while the other is in free air (a basic wet/dry bulb device). The difference between these readings is computed, and a card supplied with the instrument shows these computed figures. This is a quick and easy way to measure different rooms. Simply follow the instructions.

Reasons to Control Humidity

As mentioned earlier, the effects of high humidity can be a source of ill health, besides being uncomfortable. Here are a few reasons as to why you should control the humidity level.

An increase in pollutants, germs, microbes, etc., set up infections of high humidity. Some organisms or microorganisms thrive in warm and humid air, spreading these conditions quickly. Therefore, keeping the humidity low will stop these organisms from multiplying.

Dust Mites

If you are prone to asthma and have itchy skin, it is probably due to dust mites. These are generally found in mattresses, pillows, duvets, and bedspreads. These pests thrive in high humidity and warm conditions. So, it is recommended to keep the humidity in bedrooms between 50-60 %. This will stop the triggering of asthma and allergies.


Mold caused by dampness can affect your health. We are all different. These conditions could affect some people and not others. Keeping the RH between 30%-60% will oust any mold. Running a dehumidifier or a rock salt bucket, as we mentioned earlier, will control the humidity. There are other ways of controlling humidity as well, such as changing your daily activities.

Try some of these:

A quick shower: Long showers with hot water producing steamy air will increase the humidity. So, try a quick shower that’s not so hot instead.

Ventilate the kitchen: Cooking is always a cause of water vapor. As pots boil, steam is produced and creates damp air. Try ventilating the kitchen and use a kitchen extractor fan. These are available at your local hardware store and are reasonably priced.

Create a Balance

Breathing healthy air provides a healthy atmosphere and a healthy living environment. You can improve the environment by keeping the humidity balanced.

As we have mentioned above, there are many ways to dehumidify a room. Natural ways such as rock salt and baking soda are great for small areas, while larger areas will require the use of an air conditioner or dehumidifier.

An excess of moisture in the house is shown in many ways, such as via mold and mildew. Excess moisture triggers health issues, such as asthma. Good, enjoyable living conditions are essential to keeping healthy. Keep a balanced humidity level indoors in summer as well as winter.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.