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Dehumidification Systems (Standard) | Dehumidification Systems (Advanced) | Air Scrubbers | Fans

Dehumidification System (Standard)

When people complain about humidity, for the most part they’re talking about relative humidity. Depending on temperature, air can hold a fixed amount of water vapor; relative humidity is the ratio of actual vapor in the air to this fixed amount. For example, at a temperature of 68 degrees Fahrenheit (20 degrees Celsius), one cubic meter (35 cubic feet) of air can hold about 18 grams (.6 ounces) of water. This would be a state of saturation, otherwise known as 100 percent relative humidity. When humidity is high in your home this can have negative affects on walls, stored items, your hair, etc. Although humid air is not bad to breath, it does promote Mold Growth and walls/furniture can warp and peel from the humid air. The trick is to find a happy medium between humid and dry air. Some dehumidifier systems have meters built into them which turn them on and off regulating humidity. Enviroduct encourages you to let us inspect your home of mold or dangerously high humid areas(typically basements). With todays technological advances humidity is very easy to control in your home. Enviroduct is capable of installing standard dehumidification systems to advanced systems which are capable of pulling more moisture out of the air and can handle larger areas.


The recommended average relative humidity level is between 35% and 45%. This range will provide the best comfort for your family, while helping to protect your musical instruments, drywall, wooden furniture and other belongings or materials from the damaging effects of dryness or excessive moisture.

As relative humidity levels actually fluctuate depending on climate and air temperature, I’ve provided an average range to make it simpler to follow. How a home handles humidity depends on many factors including design, construction, vapor retarders and how airtight the building is.


What Happens When Humidity is Too High?

When there is too much moisture in your home, moist air gets trapped in corners, basements and other closed areas. This is often very noticeable in bathrooms when moisture gathers in corners and creates mildew that is difficult to remove. Condensation can also accumulate in windows, causing water to drip down the window and wooden frames to rot. This moisture provides a perfect breeding ground for bacteria

Here are a few reasons to help you in considering whether dehumidification is needed in your home or not.


Condensation on the interior glass, water beading on a window or the presence of what looks like a fog or vapor on the glass are typical signs that there is too much moisture in the room.  This often happens when a humidifier is too large for the room and puts out too much humidity.  A build-up of moisture on a window sill can eventually rot wooden casings and that wetness will allow mold to grow.  Mold will look like a black or dark grunge on the bottom window trim, or in the track of a patio door.



Because steam rises, bathroom moisture problems are often found on ceilings or up in the corners of the walls.  Bathrooms that do not have efficient fans to divert steam and humidity to the outdoors, most often have some problems with mold.  Mold can grow on wall,

ceiling, under/around the toilet or behind the bath or shower surround.  A leaky toilet or plumbing can also cause moisture problems. Excess moisture can cause black mold to grow, which can in turn cause serious health issues.  You don’t have to see the mold for it to affect you; it just has to be present somewhere.

So why not give us a call so one of our experts can use some of our sophisticated tools to determine if your health can be effected by too much having to much moisture inside your home which can easily be controlled.


The presence of a musty odor in basements, crawl spaces, entrances and garages signals the presence of mold and mildew. Moisture could have been one-time event or a recurring problem. Possible causes range from improper window/door seals, construction sealing issues to wet basement areas from high ground water seepage, which can be a natural occurrence in your particular locale or by inadequate weeping tile installation around the home.


If Spring ground water dampness has become a recurring problem or you have purchased a home that has white or grayish water level marks in the basement, you need a dehumidifier on hand to remove the extra moisture should these events occur. It would also be a good idea to investigate why your basement is prone to water which may be from inadequate wipeing tiles around the home, concrete that needs to be repaired and sealed, or it may simply be because the house was built on a historical river bed or low plain.


Whether you’re buying a home or RV, you should always look for signs of excess moisture problems, which may require corrective action and can also become an annoyance and health concern, if it proves to be a recurring issue.  Tell tale signs that a home has had water problems are mold or mildew in corners of walls, bathroom ceiling/walls and water level marks in the basement. To Play it safe its best to call us and have an expert come down with sophisticated tools to help you made a good decision of if dehumidification i s needed.


The basic functional principle of a condense drying dehumidifier is really quite simple. A fan draws in humid air and carries it through a refrigerated evaporator. The air is cooled well below its dew point. The water condenses on the cold surface of the evaporator and drips into a water container or is led directly to a drain. Then the cold dry air continues through a hot condenser which heats it up and returns it to the room to pick up new humidity. This procedure is continued until the desired condition is achieved.

In the illustrated example 25°C hot air with 70% RH (relative humidity) (1) enters the evaporator. Inside the refrigerated evaporator (2) the air temperature drops to 17°C and the RH increases to 88%, resulting in condensation and the water is dripping off into a container.


To remove all of the water even with relatively dry air conditions, it is important that not all the air is cooled down by the evaporator as there is a risk that the dew point cannot be fully achieved. Instead only part of the air is led through the evaporator to ensure maximum condensation while the rest is by-passed as shown above. This results in a mixed 18°C and 85% RH air flow between the evaporator and the condenser (3). When passing the hot condenser the mixed air flow will ensure that the condenser is sufficiently cooled. The final result is an outlet air temperature from the dehumidifier of 33°C and 35% RH (4). The temperature is increased because energy is added by the compressor and by the latent heat from the condensation process.

Humidity Control

The internal hygrostat on the display allows control of exactly how much you want to lower the relative humidity. Set the degree of relative humidity required, and the hygrostat will automatically stop the dehumidification process when the value is met. This way you do not risk possible damage from drying out materials too much, and you get a much more energy efficient dehumidification process.

Older CDTs do not come with a built-in hygrostat, but an external hygrostat can easily be connected to all CDTs if needed.

Temperature Control

If the room temperature is outside the operating range (3-32°C) the dehumidifier stops. It starts up again automatically when the room temperature is once again within the operating range. This means that the dehumidifier will keep running as long as the room temperature remains within the operating range, continuously reducing the RH-value.

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