Predicted percentage dissatisfied with ankle draft.
Indoor Air
; 27(4): 852-862, 2017 07.
Article
em En
| MEDLINE
| ID: mdl-28005297
ABSTRACT
Draft is unwanted local convective cooling. The draft risk model of Fanger et al. (Energy and Buildings 12, 21-39, 1988) estimates the percentage of people dissatisfied with air movement due to overcooling at the neck. There is no model for predicting draft at ankles, which is more relevant to stratified air distribution systems such as underfloor air distribution (UFAD) and displacement ventilation (DV). We developed a model for predicted percentage dissatisfied with ankle draft (PPDAD ) based on laboratory experiments with 110 college students. We assessed the effect on ankle draft of various combinations of air speed (nominal range 0.1-0.6 m/s), temperature (nominal range 16.5-22.5°C), turbulence intensity (at ankles), sex, and clothing insulation (<0.7 clo; lower legs uncovered and covered). The results show that whole-body thermal sensation and air speed at ankles are the dominant parameters affecting draft. The seated subjects accepted a vertical temperature difference of up to 8°C between ankles (0.1 m) and head (1.1 m) at neutral whole-body thermal sensation, 5°C more than the maximum difference recommended in existing standards. The developed ankle draft model can be implemented in thermal comfort and air diffuser testing standards.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Satisfação Pessoal
/
Temperatura
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Sensação Térmica
/
Movimentos do Ar
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Tornozelo
Tipo de estudo:
Diagnostic_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Female
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Humans
/
Male
País como assunto:
America do norte
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article