Should we accept that our ducts leak or should we do something about it?

The leaking of air ducts, especially supply air, has the potential to ruin indoor air quality.


Too often building managers don’t take this problem seriously enough. There’s no casualties, at least at the moment, so why would they care. The airflows meet the minimum requirements, right? 


Then why is it a risk and what could possibly happen?


The leaking of a supply air system may, at some point (a crack, hole or joint), in the system, cause a Venturi-Phenomenon ( This means that there is a negative pressure, even though one would assume it is the other way around the whole way through the supply air system, which causes the duct to suck dust, dirt and unwanted particles from a crack and throw them out through the supply air grills and diffusers to the air we breath. As you can probably imagine, inhaling these things can cause problems in your lungs, difficulty breathing and all sorts of unwanted things. Not to mention the energy losses (read money).


In the management point-of-view this means maintenance, like cleaning the ductwork, and inspections in smaller intervals and that correlates to loosing money in something that could be solved relatively easily in most cases. Of course there are exceptions where there are no simple solutions to solve a problem. But those are problems that have to be solved nevertheless. 


We should pay more attention to the tightness of our ductwork not only for health reasons but also for saving money!


Did you know that you can seal your ducts from the inside? Check out our website ( and contact us or your local Aeroseal partner.

Energy efficiency

Energy efficiency is a popular pair of words nowadays. Buildings are being invested in because they are property, and property is something worth taking care of to get the best possible profit and to maintain it's value. 

Buildings are being updated with the latest automation hardware and software and VAV units' fans are switched to bigger, more robust and powerful ones. Still, sometimes it feels as if the very basics like the tightness of ventilation systems and it's influence in energy consumption and indoor air quality in general is forgotten.

Leaking ducts cause all sorts of problems, like high temperature even though the cooling system is at maximum value, stuffy air or sewerage odours. All of these are a distraction when one should be most efficient and productive. Eventually this will cost money. Not to mention the annoyance which, 90% of the time rightfully, comes across from the people using the building.

Just think of what kind of savings and what kind of indoor air quality we could achieve if for example the ventilation system's tightness class of a seven storey building from the 1970's to 1990's would be C or D when the starting point is class A, maybe even double?