English

Seven federal buildings ranging in size from 1900 to 48000 m2 of floor area were pressure tested to determine the airtightness of the building envelopes. These tests are part of a larger project to evaluate the thermal integrity of the envelopes of federal buildings. The buildings were pressurized using the air-handling equipment in the buildings and a constant-injection, tracer gas technique to measure the airflow through the fans. In addition, selected windows in some of these buildings were pressure tested separately to determine the airtightness of individual components.

Air infiltration and ventilation rate measurements were made during all seasons of the year in eight federal office buildings using an automatic air infiltration system designed at the National Bureau of Standards. The eight federal office buildings were located in Anchorage, Alaska; Ann Arbor, Michigan; Columbia, South Carolina; Fayetteville, Arkansas; Huron, South Dakota; Norfolk, Virginia; Pittsfield, Massachusetts; and Springfield, Massachusetts.

Induced-pressure measurements were made in the tower of an eleven-story office building usiInduced-pressure measurements were made in the tower of an eleven-story office building using a fan. The fan was used to depressurize the entire tower as well as a single floor. Sulphur hexafluoride (SF6) tracer gas was used totrace air movements from floor to floor during single-floor depressurization. Average flow coefficients for the tower and for the single floor were estimated from single point measurements. The effect of opening and closing office doors also was determined.

Air leakage measurements by the tracer dilution technique were performed in five military aircraft hangars. The hangars were located in regions of the country having diverse weather characteristics. In several of the hangars, distinct measurements were performed to assess the degree of homogeneity of the air-tracer gas mixture in these large volume structures. Air leakage rates in the range of 0.6 to slightly above 2.0 air changes per hour (ACH)were measured. Surprisingly, these values do not differ significantly from those which might be measured in single-family residences.

Research and test results presenting measurements of air infiltration rates in residences are reviewed. In particular, comparison of electric and combustion heating shows (on average) infiltration rates to be 0.1 to 0.25 higher for residences with combustion heating.

The airtightness of 82 passive solar homes located throughout the United States was studied using tracer gas measurements of air infiltration and pressurization testing. The air infiltration measurements employed the tracer gas decay technique in a low-cost mode employing air sample bags and off-site infiltration determination. The infiltration rates measured under natural conditions ranged from about 0.05 to almost 2 air changes per hour (ACH). The pressurization test results ranged from 1 to more than 30 ACH at 50 Pa, with an average of about 10 ACH.

Data from detailed tracer concentration decay and induced pressurization measurements were obtained in tests of duplex and row apartments at Norfolk, Virginia and Pensacola, Florida to accurately determine air leakage characteristics of selec

Discusses the various causes of unwanted air infiltration in dwellings. Illustrates diagrammatically the commonest structural faults leading to adventitious air infiltration and gives methods of overcoming them. Notes the average cost of such improvements.

In December 1985 the Federal Republic of Germany joined the International Energy Agency's Annex V, the Air Infiltration Centre, as the twelfth participant. This report describes and summarises German research and development activities in the areas of ventilation, air infiltration andindoor air quality.

Work has been in progress for several years on the revision of Byggeforeskrifter (Norwegian Building Regulations), and the new chapter 54 sets quantitative requirements for the air tightness of sections of a building and the building as a whole. In this project, good and bad solutions are illustrated and an effort is made to show the importance of good workmanship. The commonest types of leakage were identified by examination of Leca pipes.The conclusion drawn from the investigations was that Leca pipes should be surface treated to prevent large air leakages.