This paper is describing the preliminary results of the Annex 27 work aiming at developing simplified tools for evaluating domestic ventilation systems. In this paper is given the tool to evaluate a system's ability to deal with different indoor air quality (IAQ) matters. In the work is used sophisticated simulation programs studying pollutant concentration either for each person or in an individual room. The evaluation is to be applied on houses that mainly are heated. This means that the tools are restricted to the heating season.
This paper presents a study of the dynamics of the turbulent mixing of a hot or cold air stream with the air in the interior of a building zone. Observations and CFO results of transient temperature behaviour in a fully developed jet flow field are presented. A simple model for the characteristic time-constant of the mixing process in a room is derived. The mixing of a turbulent jet, as a function of position inside the room, is also discussed. This mixing time-constant plays an important role in total system dynamic behaviour and stability.
In Amstelveen, The Netherlands, an apartment complex of forty two units has been build. Sixteen units are extreme low energy apartments. These apartments are very well isolated and have air tight facades.
Indoor air flow induced by a fan-coil unit in an air-conditioned environmental chamber is studied experimentally. The supply Archimedes number which is a macroscopic number describing indoor air flow is measured and related to the
centreline velocity and temperature decay of the cold air jet issued from the fan-coil unit. The space air diffusion and the thermal comfort using respectively the Air Diffusion Performance Index (ADP]) and the Predicted Percentage of dissatisfied (PPD) are evaluated. Evolution of these indices with the supply Archimedes number is discussed.
When talking about air-conditioning systems in buildings people argue with high energy consumption of those systems. They do not take into account that it is not possible in many climates to realise several indoor thermal conditions by merely opening windows.Within the framework of the research project SANIREV, sponsored by BMBF and ROM, the Hermann-Rietschel-lnstitute make tests about the use of window ventilation. For different roomloads and out-door-conditions the room conditions are determined. Now we got the first results.
Within the framework of full-scale experimental validation of the global building energy simulation software programme CLIM2000 developed by Electricity Applications in Residential and Commercial Buildings Branch of Electricite De France (EDF is the French utility company) Research and Development Division, an experimentation has been carried out in a 100 m2 real house from Oct 95 to May 96. The first step was to predict in « blind way » the total electrical power consumption of the house on the basis of three different meteorological situations (cold, hot and medium).
Knowledge of the authority of control dampers in HVAC systems may be used for diagnostic purposes or to enhance control performance. In this paper, a method of estimating damper authority in air distribution systems is described. The method only requires measurements that are normally available in modem HV AC systems with digital controls. The method is based on a technique that allows the static pressure drop across a branch to be regulated even if that pressure is not measured. Experimental results on a Variable Air Volume (VA V) air handling unit demonstrate the efficacy of the method.