When it comes to insulation, there are dozens of different properties that affect the application, usefulness, and success of insulation. From thermal conductivity to fire resistance, these characteristics are all important to consider before choosing insulation for your industrial facility or commercial business. This week we are going to discuss the property of hygroscopicity and how that affects insulation.
The Science
Hygroscopic materials are those that can absorb and store moisture from the surrounding air. You read that right, these materials don’t dissolve a liquid, ie: absorption. They actually cause water molecules to adhere to their surface, ie: absorption. When the relative humidity shifts, this change in pressure releases the moisture from the material to regain equilibrium.
The Application
There are some insulations that are especially hygroscopic such as cellulose or any type of natural fibre insulation such as wood fibre, sheep wool, and hemp. These are used in applications where it is necessary to regulate humidity inside of a building. For example, heritage and traditional buildings are usually constructed from materials such as brick, stone, timber frame, render, or paint made from lime. These vapour-open materials require an insulation that is hygroscopic in order to avoid mould growth and wall damage.
The Savings
These hygroscopic bio-based insulations have presented strong evidence of reducing energy consumption. In fact, Osanyintola and Simonson (2006), estimated that hygroscopic materials may reduce heating and cooling energy consumption by up to 5% and 30%, respectively. Of course, that means the insulation must be combined with well-controlled heating, ventilation and air conditioning systems. Research is still being done into the positive effects of hygroscopic materials on energy consumption.
In some structures, hygroscopicity is a necessary property of properly installed insulation. If you want to know the types of insulation that are right for your unique application, contact the experts at Westcal Insulation today!
