5 Reasons Why Your Motorhome Blowing Particles Out Of Vent


RV is an excellent option for folks who enjoy traveling frequently. Like others, I have one of them, and I have used it for a while. In the first period, it was working fine, but after quite a few years of purchase, I noticed several problems. One of them was some brown particles coming out of its vent.

I discovered several causes for this issue, including a poor air filter, a malfunctioning burner, styrofoam particles, etc. Even though these problems occasionally don’t impact your well-being, they are frequently upsetting.

In this article, I’ll go into further depth regarding the cause of this problem and the steps I take to fix it. So, if you’ve already encountered this problem, keep reading.


Types of Vents used in Motorhome 

Vents carry out a variety of tasks for your RV. They aid in preventing rain from reaching your RV while allowing ventilation in and out. The most commonly used material for ventilation is plastic. 

Though many colors and sizes of vents are available on the market, they are divided into three categories. 

Manual Single Handed Standard Vent (Without Fan)

This is the standard manual vent. The automated regulating mechanism and fan are absent from this vent. It simply has one handle that you may use to open or close the vent.

Manual Single Handed Standard Vent (With Fan)

It’s an upgraded model of the previous one because, in this vent, you will get a fan. However, this is a manually operated vent because it has no automatic open or closed system. You have to use your hand to open or close it. Additionally, this vent needs an energy source for its fan.

Automatic Vent (With Fan)

This is a fully automatic vent with an exhaust fan. It is the most advanced and expensive vent. This vent has an automatic open and close function which will help you to open or close it with the help of a switch.

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Why Is Motorhome Blowing Particles Out Of Vent? 

When I discovered the particles blowing out from vents, I tried to find out why. After long research, I discovered several reasons behind this issue. 

Some of them are easy to solve, and you don’t have to call an expert. But some others aren’t. Below are some of the main reasons for the issue which I found: 

1. Low-quality Air Filter

An RV’s AC system draws air inside and passes it out the other side, much like any other AC system. A filter plays an essential part in this function. Filters stop any dust or other particles from entering the air conditioning system.

However, they cannot function if you use an air filter with a low MERV rating. Because of this, dust and other particles may enter the AC system easily, and the AC then blows those particles out through its vents. 

To solve this issue, I replaced my air filter with a new one with a higher MERV rating.

2. Malfunctioning Burner

This is another typical cause of the problem that I discovered. I noticed that if the furnace runs with a broken heat exchanger or a bad burner, it can not effectively burn the fuel it ought to. 

In this situation, they produce carbon monoxide, and you will notice white particles coming from the vent.

You must examine the furnace pilot light to ensure that these components operate correctly. If you see its color is blue and hardly visible, you can be sure it’s operating correctly. But, if the flame is orange or yellow, this will indicate that something is wrong. 

If you discover this problem, switch off the furnace and get in touch with a qualified RV mechanic as soon as you can since it is a very dangerous condition.

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3. Lubricants

The lubricants applied in the production process are the most frequent source of this issue with new ventilation systems. Producers typically lube the metal while bending or manipulating it to create the interior components of your heating system. 

Using those equipment heats and cools the lubricant, which finally emits a powdery-white material. Generally, this lubrication will eventually vanish, and the issue will be automatically solved. 

4. Mold

There is a significant possibility that black mold forms within vents if you observe black particles flying out of vents. Typically, it is challenging to remove this black dust. 

If you see this, I strongly suggest getting in touch with a specialist to have it inspected since black mold is quite hazardous.

5. Styrofoam Particles

For the past couple of months, whenever I switch on the air conditioner, Styrofoam pellets start to come from the vents. Then, I discovered that RV unit ceilings and walls are extensively insulated with polystyrene.

This is expected since Styrofoam will eventually break down and keep deteriorating for ages if you do nothing to halt it. Then I will consult a skilled technician to resolve this issue.

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Is Blowing Particles From Vents Harmful For Motorhome Operation?

This is quite difficult to answer. Because there are a lot of aspects connected to this answer. In general, most of the time, this is not harmful. 

But, if you notice dark and carbon monoxide particles blowing out from the vent, this can be dangerous. 

This issue can affect your motorhome operation. In this situation, you should take the help of an expert technician.

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There’s a chance that you still have some queries even after reading this article. In this section, I did my best to respond to the queries raised the most. So, read this FAQ to receive the information you need.

Why do RVs have vents?

Vents are essential to maintain clean, fresh air within your RV. They aid in removing stale air from the RV and bringing in fresh air from the outside. One to two of these vents is present in every RV.

Why is there so little air flowing from the vents?

The most common cause of a lack of airflow from your RV’s vents is a clog in the vent. Besides, accidentally, you may obstruct your air vents, or perhaps you covered the vents on a cool day and forgot to reopen them.

How frequently should you clean RV’s vent?

Professionals recommend cleaning the air vents every two to three years to stop numerous service and health issues. Air duct cleaning should be done more regularly than advised in RVs with pets or kids who have allergies.

Is it the dust or the mold in the vents?

There is a strong likelihood that mold forms within vents if you see any black patches or dust surrounding them. A moist, slimy feel is another sign of black mold; these areas are sometimes hard to remove.


Do not panic if you encounter any of these problems. But, if you notice the vents are blowing too much dust, consult a qualified specialist. They will examine your system, make the necessary repairs, and quickly increase ambient air quality.

By carefully examining many warning signs, servicing your RV regularly, following the manufacturer’s instructions, and taking good care of it, you may also avoid unnecessary troubles and costly repairs. 

Finally, always make an effort to keep your RV’s essential components, particularly the heating system, in good working order.

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