Evaluation Of The Emissivity Of Outer Surfaces Of Building Constructions

Evaluation Of The Emissivity Of Outer Surfaces Of Building Constructions

Stať ve sborníku v databázi WoS či Scopus

The composition of coating materials, applied in the exterior layers of building constructions, affects the value of emissivity, important for the radiation of ther-mal energy from outer surfaces of such constructions into the free space. In case of most coating materials the rather rugged surfaces do not admit any di-rect measurement, based on the monitoring of the intensity of rays, reflected from the surface. The appropriate approach is the integral measurement of the reflected diffusive radiation from the surface, using the "ball method": its interior sphere for the wavelengths from 5 to 20 ?m must be gold-coated. However, such expensive equipment is not available in the Czech Republic, thus the indi-rect method of the measurement of the thermal resistance of the air gap has been applied where both the thermal flow and the heat radiation are active. The results of such measurements give a chance to evaluate the proportions of both these processes of heat propagation. The paper demonstrates practical results for various coating materials, supported by the automatic measurement device LAMBDA (Holometrix, USA).

The composition of coating materials, applied in the exterior layers of building constructions, affects the value of emissivity, important for the radiation of ther-mal energy from outer surfaces of such constructions into the free space. In case of most coating materials the rather rugged surfaces do not admit any di-rect measurement, based on the monitoring of the intensity of rays, reflected from the surface. The appropriate approach is the integral measurement of the reflected diffusive radiation from the surface, using the "ball method": its interior sphere for the wavelengths from 5 to 20 ?m must be gold-coated. However, such expensive equipment is not available in the Czech Republic, thus the indi-rect method of the measurement of the thermal resistance of the air gap has been applied where both the thermal flow and the heat radiation are active. The results of such measurements give a chance to evaluate the proportions of both these processes of heat propagation. The paper demonstrates practical results for various coating materials, supported by the automatic measurement device LAMBDA (Holometrix, USA).

emissivity, thermal radiation, algae occurence on ETICS

emissivity, thermal radiation, algae occurence on ETICS

ŠŤASTNÍK, S.; VALA, J.; STEUER, R.

13.10.2006

Vydavatelstvo STU

Kočovce, Slovensko

80-227-2536-6

Proceedings of the seminar Thermophysics 2006

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