Make Condensation History
Any insulation material can prevent condensation but understanding how condensation occurs can help you to select the most effective insulation.
In the first article in this series, we looked at the most basic principles of condensation. Now that you know how condensation is formed, and why it's a bad thing on air-conditioning and refrigeration pipes, you're probably wondering exactly how to stop it. Fortunately there is an easy answer.
Only cold surfaces experience condensation
Condensation can only form when air holding gaseous water vapour comes into contact with a cold surface that cools the air and reduces its ability to hold water vapour. The critical temperature is known as the dew-point temperature and water will only condense out of air when it comes into contact with a surface that is colder than this.
Applying insulation around a cold pipe “keeps the cold in”, and the outer surface temperature of the insulation is much higher than the pipe the insulation has been applied over. If the surface temperature of the insulation is higher than the dew-point temperature then there will be no condensation – even if the temperature of the pipe itself is well below the dew-point.
Insulation covers up the coldest surfaces
What the visual representation shows very clearly is how, as you increase the thickness of insulation, the “cold” is kept closer and closer to the pipe and the outer surface temperature of the pipe edges nearer and nearer to the ambient temperature.
Provided the dew-point temperature occurs within the insulation there will be no condensation on the surface (there are still major advantages to pushing the dew-point temperature as close to the pipe as possible. This is something we'll discuss further in a future blog entry).
Select the right insulation thickness
Aside from a visual representation of the temperature gradient inside the insulation, Kaimann has also developed a set of tools that enable you to calculate the minimum thickness of insulation necessary to stop condensation forming given a specified set of conditions. These can be found on our website or in the Kaimann Technical Service App, available from the
Apple App store or the
Google Play store.
Of course, controlling surface temperatures isn't the only thing that's important when it comes to stopping condensation and in the next article we'll start to explore vapour pressure – something key to understanding why you need an effective water vapour barrier.