How do mechanical roof ventilation units work?

And what do you need to consider?

If you are looking to remove moisture, harmful gases and heat from the loading compartment of your commercial vehicle, it is advisable to install a roof ventilation unit. But how does a mechanical roof ventilation unit actually work?

Mechanical roof ventilation units

Most mechanical roof ventilation units have a rotating extraction system. This is a rotating cap which is driven by the wind when the vehicle is moving so that air is extracted from the load compartment. But a roof ventilation unit on its own will not really help that much. The air is not exchanged, for example.

If you want a constant flow of air in your load compartment, you can combine a rotating roof ventilation unit with a floor drain in order to create low pressure. Fresh air, as well as dust and exhaust gases will then be sucked in through the floor and the roof ventilation unit will then remove the gases. This creates a constant flow of air from the floor plug at the bottom of the load compartment to the roof ventilation unit above. However, a constant flow of air doesn’t mean the same as air-conditioning.

If you want air-conditioning in the load compartment of your van, the best option is to install a mechanical roof ventilation unit with push and pull technology. A ventilation unit with two separate holes will ensure powerful air circulation and, as a result, the whole of the load compartment in your van will be demonstrably ventilated. A big plus with this is that you no longer need a floor drain, meaning you don’t have to drill a hole in the floor of your van.

The illustrations below show how the air circulates in the various solutions.

Rotating roof ventilation unit

Rotating + floor drain

Roof ventilation unit with push and pull technology