It’s March, spring is just around the corner and many individuals are in the spring cleaning mode.  One of the places you should not overlook is your crawl space.  Many of these crawl spaces are dirt and are located in the humid southeastern United States and do not have a crawl space dehumidifier or vapor barrier.  It is not uncommon in the southeast to see crawl space humidity levels at 50% to 90%.

For several decades, American homes have been built over dirt crawl spaces because it was simple and cheap.  Unfortunately, many of these dirt crawl spaces were vented based on the faulty assumption that these vents would allow moisture to escape from the crawl space.  In fact, many outdated state codes still require this.  We now know that these vents actually increase the relative humidity level.  The natural upward air movement draws air from the crawl space vents up into the living space of the home.  Did you know that up to 40% of the air you breathe in your home was once in the crawl space?

Vented dirt crawl spaces create a ticking time bomb of potential problems.  The bare soil contains high levels of humidity that natural airflow patterns move upwards into your home.  This is referred to as the "Stack Effect".  This means that not only are mold spores and allergens entering your living space, but that moisture is entering the entire floor framing system under the house, paving the way for damaging wood rot.  This can result in expensive structural repairs to girders, floor joists and sill plates.

The long-term solution to these problems is not to put band-aids on the symptoms, but to focus on eliminating the source(s) of moisture.  Immediately fix any groundwater, plumbing or other obvious leaks.  Make sure gutters and downspouts are clear and drain away from the foundation of the house.  Remember, the longer you ignore moisture problems in your crawl space, the more expensive the repairs will be.  You will have to find a contractor or qualified handyman to crawl under your house and replace boards amidst all the wiring, plumbing, duct work and bridging present in the crawl space.

To protect your home and your health you should put down a vapor barrier and install a crawl space dehumidifier.  Although there are certain steps to follow, you don’t necessarily need to be Bob Villa to install a vapor barrier and dehumidifier in your crawl space.  You’re biggest risk is doing nothing.

Here’s the answer.  Air in your crawlspace is always more humid than the air in the house.  And this is because cool ground temperature keeps the crawlspace colder than the air in your house.  Because of this temperature difference, your home’s living areas can feel dry, while below, crawlspace humidity runs rampid.

Here are a couple terms to know:

1. Dew Point = Temperature at which water vapor condenses
2. Relative Humidity (R.H.) = % of moisture present in relation to of moisture the air can hold.

In other words, relative humidity is the percent of water in the air.  When R.H. hits 100%, water will condense, rain or snow.  Dew Point is the temperature when this happens. Here are a few scenarios to show what happens in your home and crawlspace during typical weather conditions.

NOTE: Crawlspace R.H. (relative humidity) should try be 40% or less in order to keep Dew Point around 10-15 degrees below the crawlspace temperature.  EPA recommends 40% – 50% R.H.  This will control dust mite and mold populations.  A crawlspace dehumidifier should always be used during humid or rainy weather.  Humidity in the living area above, can be as high as 50% or 60%, based on comfort.

As the winter air enters, the humidity drops slightly within the crawlspace.  Notice relative humidity is 62%, beyond what the EPA considers acceptable.  As the air migrates upward, it warms greatly and relative humidity drops drastically.  The house feels dry, but the crawlspace still requires dehumidification.  To control dust mite populations, it is recommended that the crawlspace be kept at 40% R.H. all year long.  Unfortunately, most dehumidifiers will not work at a 45° temperature.  Though, our Dri-CrawlSpace^® dehumidifiers will run just fine all the way down to 33°.

Still winter time, but here we have a cold rainy day.  It will still feel dry indoors, but notice as the outside air enters the crawlspace, relative humidity only drops to 70%.  During this type of weather, your crawlspace dehumidifier should be running.  Be sure to choose a Dri-CrawlSpace^® Dehumidifier because it is one of the few that can operate in temperatures this low.

This is the type of weather where mold really thrives, especially if it were to rain.  It’s too cold to run the air conditioner, so high humidity goes unchecked.  If it were raining, relative humidity outside would be 100%.  This would raise the dew point to 55°.  With the crawlspace at 58°, humidity would rise to a whopping 89%.  All your cold water pipes and exterior walls would be dripping wet.

Here’s a nice warm day with comfortable 50% humidity. But because it is so warm, dew point is also going to be warm.  Any surfaces below 60° will form condensation.  Look how high the relative humidity gets as the air cools to 65° in the crawlspace.  At 83% relative humidity, your crawlspace is sure to grow a good amount of mold, as well as make a fine home for spiders, termites, cockroaches and other pests.

The mild summer night is the worse case scenario for allergies. As temperatures near the dew point, dust mites and mold will multiply and run rampid throughout your home.  Notice how quickly food goes bad in this weather.  Also, if you notice more bugs in your home,  these are indications of high humidity.  A good crawlspace dehumidifer like the Dri-CrawlSpace^® can keep up with these humid conditions and make your home comfortable while taking some strain off your air conditioner.

For more information on crawlspace dehumidification, sign up for a FREE REPORT that reveals 7 Things You Should Know Before Buying Any Crawlspace Dehumidifier.

Mold is ubiquitous in our natural environment. There are over 100,000 different types of mold, with only a handful being dangerous. In fact, there are some molds that have proven beneficial, such as penicillin. Although most of us have dealt with mold in our lives as mostly a nuisance, further examination revels that mold in your home can have serious health consequences for you and your family.

Biological airborne contaminants such as mold, pollen spores and dust mites are classified as "bioaerosols". These bioaerosols are extremely tiny living organisms suspended in the air. Bioaerosols can cause many health problems; from the severe, like bacteria and viruses that cause infection, to mild cases of allergies. Bioaerosols may also cause allergic reactions in the respiratory tract or on the skin. Common allergic reactions include: rashes, difficulty breathing, tightness in the chest, watery eyes and running noses. Mold related illnesses could result from both high level/short-term exposures and low level/long-term exposures.

Another health problem brought about by mold is hypersensitivity pneumonitis. This disease causes the air sacs of the lungs to become inflamed when certain mold spores are inhaled by individuals who are sensitive or allergic to the spores. Mold spores can deposit on the lining of the nose and cause hay fever symptoms. They can also reach the lungs, causing breathing difficulties for those with asthma. Some mold spores are able to grow for years after they are produced. The allergens in and on them remain allergenic for years, whether the spores are alive or not. Among the most harmful types of indoor molds are stachybotrys, alternaria, mucor, chaetomium, cladosporium and fusarium.

How your health is affected by mold is dependant on the amount of exposure and your individual susceptibility. People most vulnerable are those with allergies, asthmatics, the elderly, infants and children, those with existing respiratory problems and individuals with weakened immune systems. Controlling the moisture in your environment is the key to successful mold remediation.

Even through mold is a nasty substance to have invade your home, you can usually see it or smell it when it becomes problematic. This is not the case with an even more disgusting pest, the dust mite. Dust mites are microscopic organisms that feed on human and animal dander and are the most common allergen found in indoor air. Dust mites are found in carpets, mattresses, sheets, pillows and upholstered furniture. They feed on dander, which is skin and hair particles shed by humans and animals. We provide dust mites quite a feast as the average person sheds nearly 7 million skin cells per minute.

Dust mites belong to the same arachnid family as spiders. They thrive when the humidity is between 70-80% and the temperature between 75-80 degrees. Dust mites cannot survive if the humidity is below 40%. Even though you can’t see dust mites, there can be as many as 30,000 of these minute creatures in one ounce of dust. As disgusting as it seems, the average bed may house over 1.5 million dust mites! Dust mites themselves are not allergenic, but their waste products and disintegrating body parts cause problems. Research shows that feces deposited on our skin by dust mites may make the skin more susceptible to allergens and irritants. The mites shed enzymes in their feces that are used to break down the human skin cells they feed on. These emitted molecules can cause dramatic allergic reactions in some people. Dust mites are among the most common causes of asthma.

Whether the problem in your home is mold, mildew, dust mites, or all three, the underlying reason they exist is excessive moisture somewhere in your home. Besides preventing allergen issues, excessive moisture can also aggravate arthritis and rheumatism conditions. Moisture control can be achieved by constructing a vapor barrier in your crawlspace and by using a quality crawl space dehumidifier. Our expert dehumidifier team at OscarAir, Inc. has developed what we consider to be the best value available in crawlspace dehumidification.  Go to our Home page and find out why no other unit on the market can match its value.