English

In the paper cooling loads are calculated and analysed under different distribution percentages of radiant heat sent out by indoor heat sources to the envelope of an upward displacement ventilation room with different constructions. It is found that the former approximate methods of distribution percentage will cause big errors when accurately calculating the cooling loads formed by radiant heat gains from indoor heat sources. The accurate method should be calculating the cooling loads based on the actual distribution percentage to each of the inside surfaces of the room.

Simulation is useful in many aspects of the design, control, and evaluation of buildings and their associated heating and cooling equipment. Pure experimental studies are often limited by the bounds of cost and measurement techniques, whereas simulation studies are limited by theoretical understanding and computational constraints. In particular, experiments are needed to develop the fundamental understanding necessary to create new mathematical models and to validate larger scale simulation models.

In this session 14 papers are discussed covering a wide range of topics, applications and aggregation levels. Besides papers using different simulation tools, several field tests, experiments and theoretical approaches are discussed. The majority of the papers present applications in dwellings, but also industrial and agricultural environmental issues like those in greenhouses for the production of crops and livestock buildings (pigs) are discussed.

This paper reflects the research presented in session 1 "Indoor Environment" of the present CLIMA 2000 Congress. Design and assessment of the indoor environment, mainly its thermal component, is discussed. The steps of the design process as well as the model prediction and the field assessment of the indoor environment are included in the discussion. Special attention is paid to the correct application of the requirements specified in the present indoor climate standards. Examples from research presented at this congress are used.

It is well-known that there exist indoor temperature distributions. To have more precise predictions of indoor thermal comfort and better control of indoor thermal conditions, a both detailed and fast model of the dynamic indoor temperature distributions is needed. Unfortunately, very few papers studied such models due to the complexity of fluid (air) flows. CFD can be used as a detailed model. But it is too time consuming. This paper discusses two models in this respect, the fixed-flow-field model and air-zonal model. Both models are validated with experimental results.

This paper presents the results of the first part of a research project. The objective of the project is to solve accurately the heat balance on a single glass window in a moderate climate. This procedure will allow the designer to calculate the main parameters of a fenestration (surface, orientation, overhangs, etc.), minimising the energy consumption for a specific enclosure (including heating, air conditioning and lighting).

A municipality water reticulation R22 ground-coupled reversible heat pump, was investigated as an alternative to conventional air source systems. The investigation was conducted by developing analytical models that were used for the design of a ground-coupled reversible heat pump and a conventional, also reversible air-to-air system. The models were verified with a commercially available computer program as well as with measurements on the two systems.

Industry is only using 20% of the heat subtracted from fossil fuels. The other 80% is released to the surroundings leading to an increase in the global warming effect. In contrast to this, the output of a heat pump is always more than the input, it delivers up to 67% energy savings, has less pollution than conventional heating methods and has a smaller influence on the greenhouse effect because it delivers less carbon dioxide to the atmosphere than other heating methods. The performance of a heat pump is influenced by the properties of the refrigerant that is used.

The paper presents results of a simulation and laboratory study of the performance of a zeotropic mixture R-744/32/134a in a water-heating heat pump. The goal of the research was to obtain operating parameters comparable to a system charged with R-22. The performance of R-22 served as a reference for the ternary mixture studied. A semi-theoretical simulation model was used first to examine the influence of R-744 properties on the mixture performance and to determine the optimum mixture composition. The formulated mixture, R-744/32/134a (7/31/62) was then tested in a laboratory.

The hydraulic circuit connects and influences the behaviour of all important components of a climate installation. A perceptive quantitative design of this part of a climate installation therefore seems natural and is necessary for installations with a heat pump or heat power connection. Actual practice shows that such is not the case and that especially control of part load operation of the hydraulic circuit should be improved. This article presents a method which at present is being worked out within The Netherlands by ISSO into a design guideline for advisers and installers.