Attenuation of Temperature Fluctuations on an External Surface of the Wall by a Phase Change Material-Activated Layer

• Main Authors: Dariusz Heim, Anna Wieprzkowicz
• Format: Article
• Language: English
• Published: MDPI AG 2017-12-01
• Series: Applied Sciences
• Subjects: PCM-perlite composite; thermal inertia; heat storage; attenuation; in-situ measurements; real scale experiment; building façade; temperature; solar radiation
• Online Access: https://www.mdpi.com/2076-3417/8/1/11

Periodical changes of temperature on an external surface of building envelope, e.g., thermal stress or excessive heat gains, is often an undesirable phenomenon. The idea proposed and described in the following paper is to stabilize the external surface temperature in a period of significant heat gains by the originally developed, novel composite modified by phase change material (PCM) and applied as an external, thin finishing plaster layer. The PCM composite is made from porous, granulated perlite soaked with paraffin wax (Tm = 25 °C) and macro-encapsulated by synthetic resin. The effect of temperature attenuation was estimated for two designated periods of time—the heat gains season (HGS) and the heat losses season (HLS). The attenuation coefficient (AC) was proposed as evaluation parameter of isothermal storage of heat gains determining the reduction of temperature fluctuations. The maximum registered temperature of an external surface for a standard insulation layer was around 20 K higher than for the case modified by PCM. The calculated values of AC were relatively constant during HGS and around two times lower for PCM case. The obtained results confirmed that the proposed modification of an external partition by equipped with additional PCM layer can be effectively used to minimize temperature variations and heat flux in the heat gains season.