This paper describes a numerical study of the influence of opaque external trees with pyramidal shape on the thermal behaviour of a school building in Summer conditions. The software used simulates the thermal response of buildings with complex topology under transient conditions. This software has previously been validated by real studies both in Summer and Winter conditions. The school building considered is localised in the South of Portugal. It has three levels divided into 97 rooms or spaces, 1277 main structures and 211 windows with plain transparent glass. In the model, the building is shaded by 49 ‘‘opaque’’ trees of pyramidal shape growing in front of the windows on one side of each building considered. The simulation considered a typical Summer school day with clear sky and with 800 occupants in the building. Two situations with the same configuration were analysed. In the first one, the trees (located in front of the windows) were placed to the West and South-West of the buildings, while in the second one, after a 180° building rotation, they were to the East and North-East. Both situations were studied with and without the presence of trees. Temperatures in the building and the occupant’s thermal comfort conditions were calculated.

This paper concerns the prediction of indoor air quality (IAQ), thermal comfort (TC) and draught risk (DR) for a virtual classroom with desk-type personalized ventilation system (PVS). This numerical study considers a coupling of the computational fluid dynamics (CFD), human thermal comfort (HTC) and building thermal behavior (BTB) numerical models. The following indexes are used: the predicted percentage of dissatisfied people (PPD) index is used for the evaluation of the TC level; the carbon dioxide (CO₂) concentration in the breathing zone is used for the calculation of IAQ; and the DR level around the occupants is used for the evaluation of the discomfort due to draught. The air distribution index (ADI), based in the TC level, the IAQ level, the effectiveness for heat removal and the effectiveness for contaminant removal, is used for evaluating the performance of the personalized air distribution system. The numerical simulation is made for a virtual classroom with six desks. Each desk is equipped with one PVS with two air terminal devices located overhead and two air terminal devices located below the desktop. In one numerical simulation six occupants are used, while in another simulation twelve occupants are considered. For each numerical simulation an air supply temperature of 20 °C and 24 °C is applied. The results obtained show that the ADI value is higher for twelve persons than for six persons in the classroom and it is higher for an inlet air temperature of 20 °C than for an inlet air temperature of 24 °C. In future works, more combinations of upper and lower air terminal devices located around the body area and more combinations of occupants located in the desks will be analyzed.

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.