The effect of changing surface emissivity on the natural ventilation rate of a narrow air cavity integrated in a transparent insulation façade

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26110%2F19%3APU134023" target="_blank" >RIV/00216305:26110/19:PU134023 - isvavai.cz</a>

Výsledek na webu

<a href="https://iopscience.iop.org/article/10.1088/1757-899X/609/3/032054/pdf" target="_blank" >https://iopscience.iop.org/article/10.1088/1757-899X/609/3/032054/pdf</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1757-899X/609/3/032054" target="_blank" >10.1088/1757-899X/609/3/032054</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The effect of changing surface emissivity on the natural ventilation rate of a narrow air cavity integrated in a transparent insulation façade

Popis výsledku v původním jazyce

A transparent insulation material (TIM) can be incorporated in a building element in order to improve its thermal performance, including solar heat gain. However, some overheating protection needs to be implemented. The provision of natural ventilation in a façade cavity to avoid overheating, along with other potential techniques, could require a completely different approach to TIM integration in solar façade concepts. This paper concerns an analysis of the effect of different absorber emissivity behind a transparent insulation system. The emissivity changes are primarily studied in order to determine their effects on the overall radiation - natural convection heat transfer through a narrow façade air cavity. A comparative investigation was conducted using experimental full-scale dynamic outdoor tests and the building energy simulation (BES) approach. The thermodynamic response affected by the radiation - natural convection transfer is identified, specifically during the summer peak period, that corresponds to overheating. Depending on the ventilation regime, a low emissivity solar absorber inside a narrow air façade cavity may increase the cooling energy load and temperature response of a façade by 25 and 36%, respectively, in comparison with a high emissivity absorber. When the emissivity of the zone inside the cavity was changed, significant limitations were identified in the BES calculation methods for both vented and unvented cases.

Název v anglickém jazyce

The effect of changing surface emissivity on the natural ventilation rate of a narrow air cavity integrated in a transparent insulation façade

Popis výsledku anglicky

A transparent insulation material (TIM) can be incorporated in a building element in order to improve its thermal performance, including solar heat gain. However, some overheating protection needs to be implemented. The provision of natural ventilation in a façade cavity to avoid overheating, along with other potential techniques, could require a completely different approach to TIM integration in solar façade concepts. This paper concerns an analysis of the effect of different absorber emissivity behind a transparent insulation system. The emissivity changes are primarily studied in order to determine their effects on the overall radiation - natural convection heat transfer through a narrow façade air cavity. A comparative investigation was conducted using experimental full-scale dynamic outdoor tests and the building energy simulation (BES) approach. The thermodynamic response affected by the radiation - natural convection transfer is identified, specifically during the summer peak period, that corresponds to overheating. Depending on the ventilation regime, a low emissivity solar absorber inside a narrow air façade cavity may increase the cooling energy load and temperature response of a façade by 25 and 36%, respectively, in comparison with a high emissivity absorber. When the emissivity of the zone inside the cavity was changed, significant limitations were identified in the BES calculation methods for both vented and unvented cases.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

20101 - Civil engineering

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

10th International Conference IAQVEC 2019: Indoor Air Quality, Ventilation and Energy Conservation in Buildings

ISBN

—

ISSN

1757-899X

e-ISSN

—

Počet stran výsledku

6

Strana od-do

1-6

Název nakladatele

IOP Publishing

Místo vydání

Bristol

Místo konání akce

Bari

Datum konání akce

5. 9. 2019

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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