English

This paper describes the guidelines prepared by NIST for GSA. These guidelines are organised by envelope construction system and contain practical information on the avoidance of thermal performance problems such as thermal bridging, insulating system defects, moisture migration problems, and excessive envelope air leakage. For each envelope system, both good and bad practice are discussed with an emphasis on the graphical presentation of envelope design details.

A conference room has been converted to temperature- and carbon dioxide controlled ventilation. A number of tests have been conducted with the system in different load conditions. The variables that have been measured are air flow rate, temperature and carbon dioxide concentration. The activity in the room during the measurements has also been well recorded. The main purpose has been to evaluate the ability of a demand controlled ventilation system to maintain a good indoor air quality.

This paper illustrates the principles of demand controlled ventilation systems (DCV) as applied to office buildings. Appropriate ventilation approaches and control strategies are demonstrated in this paper for small area control (ieboardrooms) and for office buildings as a whole. Findings are illustrated by the results of field experiments. Impacts on energy consumption, indoor air quality and occupant response are examined. General conclusions and recommendations applicable to similar building types are also presented.

The performance of a system for demand-controlled ventilation was investigated for a period of 1.5 years. Presence sensors of the passive infrared type are used to control the ventilation rate in each classroom. The signal from the presence sensors was recorded, as well as the CO2 concentration in the classrooms. One of the classrooms was equipped with displacement ventilation. A comparison was made between displacement and mixing ventilation to investigate the CO2 concentration in the stay zone.

A test programme has been designed to evaluate the performance characteristics of sensors for the automatic control of ventilation rates. The test programme consists of two main parts, one being the evaluation of sensor performance in laboratory tests and the other referring to long term characteristics of sensors in actual buildings. Included in thepresent evaluation are eight different types of humidity sensors, two carbon dioxide sensors and five mixed gas sensors.

Natural ventilation of dwellings is commonly applied, especially in mild and moderate climates. The disadvantage of natural ventilation is the poor control of both flow directions and flow rates within the ventilated building. To improve control, theuse of mechanical exhaust is often recommended. Though this may improve total ventilation, the ventilation of separate rooms often is insufficient still.

A test room with a Displacement Ventilation System was built. Temperature control was provided with a DDC (Direct Digital Control) System, controlling the air volume and the air inlet temperature. Air velocity and temperature profiles were measured at different locations in the room for various internal loads. The aim of the control was not only to provide a constant temperature but also comfortable conditions. the temperature gradient, the air velocity and the radiant heat exchange were taken into consideration for the comfort condition in the space.

The work in this paper contributes to the work in the IEA - Annex 20 "Air Flow Patterns within Buildings" and presents a series of full-scale measurements of the concentration distribution in a room with isothermal mixing ventilation. Vertical profiles of the concentration in the middle of the room have been measured under different conditions. With the contamination source in the middle of the room the vertical profiles were changed radically with an increase of the air change rate from n= 1.5h^-1 to n=6h^-1 due to a change in the flow structure in the room.

Air infiltration and ventilation has a profound influence on both the internal environment and on the energy needs of buildings. In most electrically heated high-rise residential buildings, in cold climates, during the peak winter conditions (below -18 deg C ambient temperature and above 15 km/hour wind velocity), the air infitration component contributes to heating load by 10 to 28 w/m2 - roughly 25 to 35% of peak heating demand. Any reduction in such uncontrolled air infiltration, without sacrificing indoor air quality, will have potential to reduce the peak heating demand.

This speech comprises a summary of two publications from the Swedish Council for Building Research (BFR); the knowledge survey "Buildings and Health" (BFR T4:90) and "Indoor climate and energy husbandry" (BFR G5:90). One central conclusion presented in both these publications is that the hygienic and climatic requirements are frequently neglected and that they must reassume a central position in the building and building management process.