Field evaluation of the performance of a radiant heating/cooling ceiling panel system

For testing different engineering solutions for energy-efficient buildings, a low-energy building was built at the University of Tokyo as a pilot project. In this building, a radiant heating/cooling ceiling panel system is used. This study aims to not only clarify the system performance but also to share our experience and results for them to serve as a reference for other similar projects. Here, the system performance in relation to its heating/cooling capacity and thermal comfort has been evaluated.

Improvement of comfort conditions using confluent jets ventilation located near the floor level in an experimental chamber

In this work is analyzed the improvement of comfort conditions using confluent jets ventilation located near the floor level in front to the occupants in an experimental chamber. In this study are evaluated the thermal comfort, the local thermal discomfort and the air quality levels. The thermal comfort level is evaluated using the multi-nodal human thermal comfort numerical model, while the local thermal discomfort and the air quality levels are evaluated by the computational fluid dynamics numerical model.

Personal heating; energy use and effectiveness

Increasing personal comfort by heating office building occupants locally means that the lower setpoint for space heating. Less energy will be used when the total energy demand from all individual comfort systems together is lower than the energy saved by lowering the setpoint. The energy saving potential is dependent on the specific characteristics of the individual heating. The important performance characteristics are the energy used per unit of mitigated discomfort and the maximum discomfort that can be compensated for.

A field-comparison of thermal comfort with floor heating systems and air conditioning systems in Japanese homes

Floor heating is characterized by small horizontal and vertical temperature differences, and might be especially suitable for Japanese homes where it is customary to sit on the floor. This paper compares thermal comfort in homes while floor heating systems and air conditioning systems were in use during winter. Each dwelling had both a floor heating system and an air conditioning system, each used on alternate weeks during the survey period.  Throughout the survey periods residents were asked about their current thermal sensation, thermal preference, overall comfort and foot-comfort.

Application of the adaptive model proposed by ASHRAE 55 in the Brazilian climate context: raising some issues

This paper evaluates the adaptive method application proposed by the last version of ASHRAE 55 (2013) standard in two different climates in Brazil. ASHRAE 55 (2013) currently allows for linear and exponential methods to calculate the prevailing mean outdoor air temperature (Tpma(out)) and both are used to establish the acceptability zones. For the exponential method, two different α were used (0.6 and 0.8). Moreover, the Tpma(out) was calculated for two different time spans (7 and 30 days).

What is the relationship between humidity and comfort at high temperatures? In search of new ways of looking at the issue

This draft paper was developed as a stalking horse for the Windsor 2014 Conference workshop on Statistics, It presents the results of summer time field work undertaken by Abdulrahman Alsheikh in the region of Damman, Saudi Arabia and the data collected shows that middle class homes families there occasionally report thermal neutrality at very high temperatures and humidities.

Towards a Dynamic Daylight Understanding

Daylighting is still the most energy efficient lighting strategy, but filtering sunlight might conflict with maximization of solar gains in winter or reducing solar heat gain in summer. In passive solar homes occupants ideally balance visual and thermal comfort. This study explores the relationship of daylight and thermal comfort in a passive solar home using an extended case study method.

A field study of thermal comfort in transitional spaces in buildings in Cardiff, UK

Transitional spaces are the spaces influenced by the outdoor climate and yet are architecturally bounded by a building envelope. It can be argued that because these spaces are neither fully outside nor inside they create unique environmental conditions that may result in different expectations and perceptions of thermal comfort by those who use them. This paper presents findings from field surveys conducted in two transitional spaces in two different public buildings during the summer in Cardiff, UK.

Residual analysis of UTCI predictions on outdoor thermal sensation survey data

The Universal Thermal Climate Index UTCI assesses the interaction of ambient temperature, wind, humidity and radiant fluxes on human physiology in outdoor environments on an equivalent temperature scale. It is based on the UTCI-Fiala model of human thermoregulation and thus also allows for thermal comfort prediction.

Measure and model of free hanging sound absorbers impact on thermal comfort

A current trend is to consider that the presence of free hanging sound absorbers (FHU) installed in Thermally Activated Buildings (TABS) reduces the thermal comfort by lowering radiative and convective exchanges with the cooled concrete slab. In this study we propose a simple thermal model of FHU which may be implemented into building simulation software like TRNSys. This model considers convective and radiative exchanges but also the air flows above and below FHU. Experimentally, we observe that a ceiling coverage of 50% leads to a operative temperature increase of 0.3°C.