Presents various measurement and inspection techniques for assessing the thermal performance of the exterior envelopes of buildings. Inspection techniques include the use of ground-based infra-red thermographic surveys, aerial infra-red surveys, tracer gas air infiltration measurements, pressurization tests for measuring the tightness of the building envelope, and spot radiometer surveys for detecting gross defects. Also considers heat flow meters, a portable calorimeter and a microprocessor-driven envelope testing unit. Provides recommended procedures for each technique.
Discusses the Hjortekar project of 6 low energy houses, built as part of the Danish Energy Research and Development Programme. Explains some of the construction details to avoid cold bridges and ensure airtightness. Test results of infiltration air change rates range from 0.02 to 0.12 ach, while other tests show less than 15% difference between calculated and measured transmission heat losses, which range from 70-155 w/degree C.
Examines and tests a number of commercial air-to-air heat exchangers to determine their performance as installed in each house. Results show that although some heat exchangers indicate a high performance level, there are many installation and operational faults. A number of recommendations are made on the selection, installation and operation of air-to-air heat exchangers in houses.
Describes large-scale field studies to investigate the effectiveness of measures to prevent condensation in some 4-storey blocks of walk-up flats in Stirling. The remedial measures in the blocks of flats are improvement of thermal insulation
Proposes a new experimental technique for investigating the natural ventilation potential of new building designs. The method tests scale models of ventilated buildings outdoors in the natural wind. Results from this method agree closely with data from a similar full-scale building. Discusses use of this method by building designers.
Describes a national demonstration of the effectiveness of an optimal weatherization programme for low-income families conducted by the Community Services Administration and the National Bureau of Standards. 101 family dwellings in 12 cities
Discusses the extension of an infiltration predicting technique to the prediction of inter-room air movements. Air flow through openings is computed from the ASHRAE crack method together with a mass balance in each room. Verifies technique by comparison to published experimental results. Results indicate that the simple model provides reasonable results for complex 2 way flows through openings. The model is as accurate as the available data, about+-20%.
One limiting factor in achieving optimum thermal performance in shutters is air leakage around the shutter edges. Describes a motor driven shutter using multilayer curtains employing a magnetic type edge seal. Measures the thermal performance of 2-layer and 4-layer shutters using a controlled environment chamber. The 2-layer shutter performs as well as a similarly sized unit in which the layers ar permanently sealed. The 4-layer unit does not perform as well as expected because of air leakage between cells at the top of theshutter.
Tests a room-size, residential air-to-air heat exchanger for effectiveness of heat recovery. Conducts experiments in a small wood frame building, the Test Chamber, on the roof of the lab building. Determines heat recovery efficiency by comparing actual heat loss to that expected due to mechanically induced ventilation. The heat exchanger recovers almost 50% of the heat contained in the outgoing air flow. Additional experiments quantify effects of fan power consumption and heat conduction through the case of the device.
Studies the airtightness of about 50 passive solar homes located through out the USA using low cost measurement techniques. Measures include pressurization tests to measure airtightness and tracer gas measurements to determine air infiltration rates. Pressure tests show a variation in airtightness of homes from 3-30 changes/hr at 50 Pa, with a median of 5-9 changes/hr.The air infiltration measurements cover a wide range from 0.05-3 changes/hr, with a median of 0.5 changes/hr. Finds that these passive solar homes are not significantly tighter than less energy-conscious houses.