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A quiet dehumidifier is rather like a unicorn, it may not exist in reality, no matter how hard you believe in it. However, much like a unicorn, no-one has really been upset because they didn’t find one either.

There is no such thing a dehumidifier that is able to run in complete silence but with advances in technology in the years to come, we may just get our unicorn sometime in the future. For now, the best we can hope for is a unit that that runs as quietly as possible.

Common Dehumidifier Noises

The reason that a dehumidifier is not able to run in complete silence is due to the nature of the components held within the housing of the unit and their need to pull air into the unit to remove moisture from it and bring down the humidity in the room.
The air is drawn into the dehumidifier housing by means of a fan. This fan operates by sucking in warm, humid air and then blowing back out into the room. This operation of the fan creates a low hum that will be heard in the still of the night but will probably not be aware of it during the daytime when there is more background noise.

The noise from the fan itself will be determined by two different factors, first; the size, or capacity of the unit that determines the size of the fan motor, larger motors obviously create more noise than smaller ones. The second factor is the speed at which the fan is operating, with higher speeds creating larger air speeds and louder operating noise levels.

There is a common misconception that the primary source of noise comes from the compressor in the unit, however, if you listen to your dehumidifier when it is in defrost mode, you will not hear the compressor working, only the fan and the difference in noise levels compared to when the compressor is operating, is indistinguishable.

The compressor might make a very low hum in the instance of your refrigerator at home, but the dehumidifier unit will be significantly smaller in capacity than the compressor used in your refrigerator.

If you are still certain that there is a noise coming from the compressor, then you unit may be getting old. As the device ages, the parts move from regular use and sometimes give off a secondary vibration. This why build quality is so critical in your choice of dehumidifier, a brand that offers a quality product is essential if you want years of hassle-free operation from your dehumidifier.

High and Low Pitch Sound

Noise levels are sometimes interpreted differently according to the quality of the noise, meaning how intrusive the sound is. A low-pitch, white noise blends into the background, while a high-pitch of the same decibel range may have you climbing up the walls after a few minutes. Most dehumidifiers operate in the low-pitch range and cannot even be heard if, for example, the television is running on low volume.

High-pitched whining may be caused by loose parts within the housing, which is a sign of low build quality, if you purchase a model from a reputable brand, backed by a solid dealer warranty, you should not encounter this issue at all.

What can we do to reduce the noise level generated by a unit that we have purchased that is of good quality and operating order? It stands to logical reasoning that a larger capacity unit, with say a 70 pint capacity, will create more noise than a smaller one that does 30 to 40 pints a day in capacity.

The bigger unit requires a bigger fan and condenser as it has a lot more air-flow to handle, however, a larger unit may only need to run for shorter intervals during the day than a unit with less capacity while still extracting more moisture from the air. The preference to a louder unit operating for a shorter period of time, or a smaller unit working for a longer time is a preference that only the user will be able to decide upon.

Whole Home Systems

Another obvious solution to sorting out the noise levels produced by a dehumidifying unit is to keep the unit as far away from the living spaces as possible, especially during the night hours when everyone is sleeping. If you already own an HVAC system (Heating, Ventilation and Air Conditioning) you can look towards to option of installing a system that will work the area of your entire home. With the use of ducting, you can install the unit in your crawlspace or basement and then fan the air out into your home via the ducting system.

Whole home systems are not cheap, but they offer the best efficiency and operating noise levels that you can get. The life-time value of the system is incredible when you think about the noise advantages and often you will find that the cost for a whole-home solution is only the same price as a few portable units, making it a real win for any homeowner that is struggling with humidity issues in all the rooms of their home.

If you already have an existing unit, then a good idea is to deaden the area of operation around the unit. This can be done by reducing vibrating surfaces that come into contact with the unit such as wooden floors, the better idea would be to put it on top of a rug. To have the sound be less intrusive and sharp.

If you decide on replacing your existing unit with a new model, then take the time to review the published specifications for the model that you are interested in before you spend your hard earned money. Compare the manufacturer ratings of the fan operating speeds for high and low speeds.

Decibel Range of Sound

When it comes to understanding the decibel range of sound, below 50 decibels will be comfortable, but just a 10% shift to 55 decibels will be a very noticeable shift in sound levels due to the logarithmic nature of sound.
Desiccant dehumidifiers operate without compressors and refrigeration systems and are the ideal solution for those looking for as low a sound level as possible. They remove excess moisture from the air by means of absorbing water molecules from the air into a material which attracts water, named a desiccant. This is similar to the silica gel that you find in a new pair of shoes, designed to keep any moisture pout of the shoe while it is warehoused and shipped to the store to be bought by a consumer.

However, even this model, while free of a compressor, still contains a fan to drag in air and push it out, and with a well-built compressor unit, you will probably get higher operating efficiency while not being that much noisier.
Desiccant models do also have other disadvantages in the fact that they are less energy efficient and more costly to run. The air that they return to the room is removed of excess moisture, but it is returned a little warmer that the ambient room temperature, while this is great for colder environments, it makes them completely unsuitable for hotter seasons or environments.

Desiccant Dehumidifiers

Desiccant models designed for commercial use are readily available, however, they are sold at a very high cost compared to the counterpart compressor systems with the smallest units being sold at price points that match the high-end range of the compressor based units. They also require ducting systems to eliminate the warm air that they produce.
The only unit that me as close to completely quiet as possible is a rechargeable unit that contains no moving parts. These systems do not offer much in the way off dehumidifying effectiveness and should not be considered above a traditional unit just for their quiet running operation. They are best suited for closets and other very small places like crawl spaces.

Heated Rod

The heated rod type dehumidifier is also a unit that has no moving parts but once again, when compared to the efficiency of a compressor unit, they are just not worth considering and are also better suited to very small spaces for operation.

The final word

In summary, it may be quite a challenge to find a dehumidifier that runs completely silent but if we take our time to select the right unit with good build quality and an efficient fan and compressor, then we can be assured of a dehumidifier that won’t keep you awake all night or distract you in the office when you are trying to concentrate. A portable dehumidifier is your best bet for a unit that runs all night in relative near silence. Follow our blog for more information and of course if you have any questions at all you can contact us today and one of the GMC Aircon team will be on hand to help with any queries you may have.

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