[article]
| Titre : |
Keeping the heat down |
| Type de document : |
texte imprimé |
| Auteurs : |
Jeff Nixon, Auteur |
| Année de publication : |
2003 |
| Article en page(s) : |
p. 26-30 |
| Langues : |
Anglais (eng) |
| Catégories : |
Anti-réflectance
Noir (couleur)
Pigments
Rayonnement infrarouge
Réflectivité thermique
|
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
IR-reflective pigments are increasingly being used to keep roofs cool. The author explains how they can save energy by decreasing heat-build-up. The growing interest in Energy Efficient and 'Eco-friendly' materials is huge and shows no signs of slowing down. Infared-reflective, or 'cool', products is one of the most talked about of these technologies. It is also one of the most misunderstood. In this context, cool means reflective to solar energy. A solar-reflective product that sits under the sun builds up less heat than that which is non-reflectuve. Many references in literature have equated 'cool products' with white products. Certainly white objects are good reflectors of the sun's heat. However, offering 'any colour as long as it is white' is not an ideal design strategy. Infrared-reflective pigments allow for the design of products that remain cool under the sun - without sacrificing colour. The benefits include energy savings, longer product life, cooler cities and improving the quality of life. The sun spans a wide range of wavelengths. Much of the total energy is absorbed in our atmosphere and never reaches the Earth's surface. The light that does get through ranges from 300-2500 nanometers (nm) in wavelength. |
| Note de contenu : |
- Wavelenghts work
- Pigment play
- Cool benefits
- Application
- FIGURES : 1. The intensity of solar energy at the earth's surface. Although a substantial portion of the total solar energy is visible to the human eye, the majority is invisible infrared region- 2. Coloured surfaces absorb light at certain wavelengths and reflect it at others - 3. Two black pigments can have very different infrared reflectance properties. IR-reflective blacks can be five times more reflective than conventional blacks - 4. A custom made with IR-reflective pigments has greater TSTR and remains cooler under the sun - 5. Despite having a greater overall IR-reflectance, the phthalo has a lower TSR. The cobalt blue's reflectance is greater from 700-1100nm, where the solar intensity is highest and contributes the most toward heat build-up |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=27827 |
in POLYMERS PAINT COLOUR JOURNAL - PPCJ > Vol. 193, N° 4469 (10/2003) . - p. 26-30
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Keeping the heat down in POLYMERS PAINT COLOUR JOURNAL - PPCJ, Vol. 193, N° 4469 (10/2003)
