pressurization

Gives a brief overview of:< 1. Measurement of air change rate using tracer gas.< 2. Measurement of air leakage using steady state and alternating pressure.< 3. Calculation methods (by hand and by computer) for predicting air exchange in a building.< Indicates where relevant research in these areas is being carried out, and outlines the role of the Air Infiltration Centre.

Reviews current methods of ventilation measurement in occupied buildings including tracer methods, pressurisation, and thermography. Gives criteria for good ventilation rate measurement techniques. Also explores new methods of measuring ventilation rates in occupied buildings. These include:< 1. Use of non-toxic tracers, including negative ions, CO2 and odour levels< 2. AC pressurisation< 3. The quantification of thermography< 4. Small-scale detection of local air velocities using hot-wire anemometry.

Describes the results obtained and the problems encountered in the sealing and testing of 15 homes in Ottawa Ontario, for the Ontarion Ministry of Municipal Affairs and Housing. Gives a data summary for the 15 homes, outlining house characteristics, reductions in air leakage, materials and time needed. Finds that the average air leakage reduction is 38.7%, and the average time taken to perform the sealing and testing is 31 hrs. Covers:

Describes the methods and considerations employed in the development of a detailed monitoring and evaluation programme for passive solar residences. Data analysis is performed by determining the hourly heat transfer of all critical energy transfer components, using an on-site microprocessor based data acquisition system. Discusses air infiltration as one of the components, and describes measurement methods, including pressurisation and tracer gas techniques.

The needs, history, procedures, and past case studies for the house doctor approach are outlined. This program of individualized instrumented energy audits and retrofits has reached a stage in development where steadily increasing numbers of house doctors are envisioned for the years immediately ahead.

Outlines a method for measuring the air leakage through the surface exteriors of an apartment, by adjusting the pressure of the adjoining apartments to that of the test apartment, so that no air leakage occurs through adjoining walls.

Measures air infiltration and tightness of Swedish houses using the tracer gas technique and the fan pressurisation technique. Uses a previously developed model correlating air tightness and infiltration to evaluate the performance of Swedish homes. Shows that it is difficult to achieve the recommended minimum ventilation rate according to the Swedish Building Code by relying on natural air infiltration. Most new homes do, however meet the Code's stringent air tightness requirements. A comparison with American houses show that Swedish homes are very tight.

Gives air leakage measurements which show that improvement of the tightness of the outer core of a building gives an energy saving of 5000 Kw/a in comparison to a conventionally constructed building.< Finds that the most leakage occurs at the joints of walls and ceiling, followed by the breakthrough for electrical wiring, the corners of the buildings, the windows, the joints of wall and floor and the joints of ducts and ceiling.< Older houses in Sweden have approximately the same rate of leakage as in Finland, ie 5-10 changes per hour at 50 pa.

Describes an energy audit being developed at LBL to determine economically optimal retrofits for residential buildings, based on actual, on-site measurements of key indices of the house. Measurements are analyzed on a microprocessor and retrofit combinations compatible with minimum life-cycle cost and occupant preferences are then determined. An important element of this audit is its treatment of infiltration.

Reports on continuous energy measurements carried out in 6 detached single-family, low-energy houses in Copenhagen. Describes a few typical construction details to illustrate solutions to the problem of cold bridges, and to demonstrate ways of obtaining airtight constructions. Measures air change rate using tracer gas decay method and pressurisation and suction tests. Works out total heat loss for a period when ventilation systems are sealed and the houses heated by electric resistance heaters.