Thermal stratification performance of underfloor air distribution (UFAD) systems

Tests were operated to analyse thermal stratification with undefloor air distribution systems supplying air at different rates and temperatures.

A tool for thermal analysis of conceptual design

In contemporary architectural design, the indoor climate receives little attention. Most architects are not familiar with the typical problems and solutions involved in climate design. However, it is this relation that provides much control over the initial climate conditions and can prevent costly artificial solutions. As a result, many design decisions are made without insight into the consequences on the indoor climate.

Perceived air quality, thermal comfort, and SBS symptoms at low air temperature and increased radiant temperature

This study investigated if low air temperature, which is known to improve the perception of air quality, also can reduce the intensity of some SBS symptoms. In a low-polluting office, human subjects were exposed to air at two temperatures 23 C and 18 C both with and without a pollution source present at the low temperature. To maintain overall thermal neutrality, the low air temperature was partly compensated for by individually controlled radiant heating, and partly by allowing subjects to modify clothing insulation.

Sensitivities in the relationship between ventilation rate, vent separation and temperture.

Investigates the functional connection between the ventilation rate experienced within a building and both the separation of the inlet and outlet vents and the temperature difference between the internal and external air. Identifies two regimes of operations: one where separation drives the situation and one where temperature is the main influence. States that considering these two regimes can have an impact on design philosophy.

Formule approchee pour determiner la temperature humide. A formula for the determination of humid temperature.

States that quite simple formulae can be used for humid air, but that this is not the case for humid temperature. Gives an overview of the iterative method to be used in this case.

Intelligence in buildings: the potential of advanced modelling.

A model-based technique is described to raise the level of sophistication of building automation systems (BAS). Models are derived using stochastic multivariable identification, and describe the behaviour of air temperature and relative humidity in a full-scale office zone equipped with a dedicated heating, ventilating and air conditioning plant. The models give good accuracy. Investigates the usefulness of the models for facilities management. The 'temperature' model demonstrated substantial improvement of temperature regulation and reduction of energy consumption.

Temperature patterns of common heat sources in rooms with upward ventilation.

Based on the literature and our long-term investigations on indoor environment, the heat source patterns (distribution, location, size, etc) have a predominant effect on temperature efficiency as well as ventilation effectiveness. Although the heat sources of ventilated rooms are various and complicated in engineering practices, some typical characteristics still exist in common.

Virtual reality presentation of temperature measurements on a diffuser for displacement ventilation.

The instantaneous temperatures close to a diffuser for displacement ventilation have been measured by using a whole-field measuring method. The air temperature was measured indirectly by using infrared thermography with a digital infrared camera and a measuring screen. By moving the measuring screen the whole field around the diffuser was measured. A method has been developed for combining the tow-dimensional measurements to produce a three dimensional representation.

The effect of temperature on the emission of formaldehyde and volatile organic compounds (VOCs) from laminate flooring - case study.

Describes a study which examined the effect of temperatures of 23, 29, and 50 Deg C on formaldehyde and volatile organic compounds (VOCs) emission from laminate flooring Type A (with particleboard as substrate) and Type B (with high density fibre (HDF). For the first two temperatures, the measurements did not show any emissions of formaldehyde and very low emissions of VOCs. At the highest temperature however, Type A showed a high initial emission of formaldehyde and VOCs, decreasing with time. There were much lower emissions from Type B.

Behaviour of inclined jet on room cooling.

States that when used with ice storage systems, cold air distribution systems are popular since they require less operating and capital costs. Stresses the importance of a consideration of occupant comfort. The study looked at air circulation and temperature distribution in a room, considering different orientation, velocities and sizes of jet for a given vertical location of air inlet and outlet on opposing walls. A control volume method was used to solve the Navier-Stokes equations and an energy equation in two dimensional rectangular Cartesian coordinates.