How to deal with black stains on air vents

After installing the central air conditioning, there may be radiating black stains around the air supply outlet. The magnificent hall and luxurious guest rooms are disappointing and unsettling due to the filth on the ceiling.

Reasons and phenomena.

The dust diffused in the air either moves with the airflow or moves irregularly. When dust collides with the wall, it is absorbed by the wall due to van der Waals gravity.

The airflow velocity at the air outlet is high, and there is more chance for dust to impact the wall surface, so the air outlet is dirty faster than elsewhere. When there is a temperature difference between the wall and the surrounding air, natural convection is formed, and here it is also dirtier than elsewhere.

Near the air outlet, there are both forced convection caused by air supply and natural convection caused by temperature difference. If there is no good filter in the air conditioning system, as little as a few months, as much as two years, the surroundings of the air vents will be dyed black.

Black stains may also appear near the loudspeaker, and at this time, the cause of the black stains is airflow oscillation, and the root cause is still air pollution.

Indoor air pollution not only affects the air vents, but also affects the entire wall.

Countermeasures.

The cause of black stains is air pollution, and the method to prevent black stains is to use good filters in the air conditioning system.

For homeowners, dealing with indoor wall decoration fading and air vent black stains caused by air pollution is very expensive, and the cost is much higher than using the highest grade filters.

The filter with F7 efficiency (colorimetric method 85%, old European specification EU7) is the preferred choice. If pursuing high quality, F8 filters can be chosen. F6 and F5 filters are not sufficient to eliminate black stains, but they can delay their generation and diffusion.

The G3 efficiency filter (weighing method 80%, primary efficiency filter) is ineffective in preventing black stains.

Once there are black stains and fading of the interior decoration, air conditioning engineers should be asked to work on the central air conditioner.

Of course, reducing the airflow velocity and changing the shape of the air outlet can also improve and delay the formation of black stains. But the indoor dust still remains, and the decoration still fades.

Key points:

Indoor air pollution → indoor decoration fading

Air pollution+local airflow → black stains

The black stains on the air vents and the fading of the interior decoration are the failures of air conditioning designers.

Select a filter with F7 efficiency.