Numerical Simulation of the Application of Solar Radiant Systems, Internal Airflow and Occupants’ Presence in the Improvement of Comfort in Winter Conditions

• Main Authors: Eusébio Z. E. Conceição, Mª Manuela J. R. Lúcio
• Format: Article
• Language: English
• Published: MDPI AG 2016-09-01
• Series: Buildings
• Subjects: solar radiation; thermal comfort; local thermal discomfort; indoor air; numerical simulations; experimental tests; coupling integral and differential models
• Online Access: http://www.mdpi.com/2075-5309/6/3/38

In this work, the use of numerical simulation in the application of solar radiant systems, internal airflow and occupants’ presence in the improvement of comfort in winter conditions is made. The thermal comfort, the local thermal discomfort and the air quality in an occupied chamber space are evaluated. In the experimental measurements, a wood chamber, a desk, two seats, two seated hygro-thermal manikins, a warm radiant floor, a solar radiation simulator and a water solar collector are used. The air velocity and the air temperature fluctuation are experimentally evaluated around 15 human body sections. The chamber surface temperature is experimentally measured. In the numerical simulation, a coupling human thermal comfort (HTC) integral model, a computational fluids dynamics (CFD) differential model and a building thermal response (BTR) integral model are applied. The human thermal comfort level is evaluated by the HTC numerical model. The airflow inside the virtual chamber, using the k-epsilon and RNG turbulence models, is evaluated by the CFD numerical model. The chamber surface and the collector temperatures are evaluated by the BTR numerical model. In the human thermal comfort level, in non-uniform environments, the predicted mean vote (PMV) and the predicted percentage of dissatisfied (PPD) people are numerically evaluated; in the local thermal discomfort level the draught risk (DR) is experimentally and numerically analyzed; and in the air quality, the carbon dioxide CO2 concentration is numerically calculated. In the validation tests, the experimental and numerical values of the chamber surface temperature, the air temperature, the air velocity, the air turbulence intensity and the DR are presented.