A computational model for the detailed design of finned-tube heat exchangers is presented. Coils are discretised into tube elements for which the governing equations are solved using local values of temperature, pressure, physical properties and heat transfer coefficients. Single phase, condenser and evaporator cases can be treated using water, R22, R134a, and various refrigerant mixtures based on R32, R125, and R134a.

NEXT 21 is the experimental residential building ,completed in October 1993 at Osaka. Main theme of this project is to create comfortable housing for early 21th century life without the increase of stress to urban environment. For this purpose many experimental design ,such as, earth covered roof , ecological garden, greenery for wild birds and many efficient mechanical systems were applied to this building.

In this paper, a part of the results of a study realised in Chambéry to develop the use of solar energy in small and medium European cities is presented. This analysis is based on the evaluation of the solar potential of the city, then a balance of saved

Tests were conducted on two instrumented air-cooled water chillers (15 kW and 30 kW cooling capacity). Refrigerants evaluated included R22 as the baseline fluid, R407C and R410B. When testing with R407C, the retrofit procedure did not involve any major hardware change. The results with the first chiller equipped with a counter-current plate evaporator showed that both capacity and EER are maintained within 5%. The second chiller, which was not equipped with a counter-current evaporator showed poorer results.

An approach to the steady-state simulation of heat pumps and refrigerating equipment is presented. Novel features of the proposed model are the strategy and formalism adopted in the programme development. Individual mathematical models for component design are linked to enable the simulation of a basic vapour compression cycle. This paper introduces some of the component modules, which can be used for pure as well as mixed refrigerants.

Researchers involved in studying problems concerning the built-up environment face an objective complexity, of easy instrumental evaluation, and a subjective complexity which is psycho-physiological concerning human beings with different individual reactions to the same exposure conditions.

On the way to the solution of our energy-problems, the conditioning of buildings is the most importantsector. We have to create new buildings, that produce more energy than they need in the course of ayear, so called plus-energy buildings and we have to perform large-scale retrofitting of existing buildings. Priority must be given to increasing energy-efficiency. Having fulfilled this, the implementation of renewable energy has to be undertaken.

The Energy Policy Act of 2005 (EPAct05) requires that federal building energy-efficiency performance standards be revised. New federal buildings must be designed to achieve energy consumption levels at least 30 percent below the levels established in the currently applicable version of standards published by the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) Standard 90.1 or the International Energy Conservation Code.

There is worldwide plea to reduce carbon emission. Several governments in East Asia recently have responded by setting higher indoor temperatures in summer. But the public need to be convinced that such practice would not sacrifice indoor environmental quality, especially thermal comfort of the occupants. To implement such a measure, suitable ventilation system(s) to work under theunconventional conditions should be identified. Stratum ventilation, a new mode, is proposed for the elevated indoor temperature.

The current rate of consumption across Europe is leading to environmental problems. We need toreduce our impact to nature - our ecological footprint - by two thirds to achieve a sustainable andglobally equitable level. There is a strong need for more efficient and sustainable buildings. At present it is difficult to define the performance of buildings in an objective way to efficiency and sustainability. Goal of this project is to examine and to understand differences between different green building assessment rating systems approaches when applied to high performance buildings.