Describes methods of measuring the three-dimensional flow field using a three-sensor hot-wire probe, with emphasis on the techniques developed by the author's group at the Pennsylvania State University. The hot-wire equations, data processing procedure, calibration techniques, and a discussion of various errors in the measurement are included. Some typical data acquired by thisprobe is also included.
Discusses and analyses the characteristics of methods of determining local air flows through the building envelope, methods of determining the air leakage and ways of determining air changes in rooms. Summarises in a table methods of determining local air flows. Of the air leakage methods, treats static and non-static methods. Considers three commonly used tracer gas methods for air change measuring methods.
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.
Reviews new regulations and their consequences for external wall structures. Considers energy savings, air tightness requirements, U-values, air movement and zone division, heavy and light structures, building classification according to room temperature, incidental heat gains from insolation.
Reports on the Swedish Energy Saving Survey of 1980, which produced two kinds of estimates on the effects of a number of energy conservation measures:< 1. Theoretical estimates based on simple degree-day models.< 2. Empirical estimates based on the amount of savings actually obtained in a house after retrofitting.< Compares the two methods of estimation, which shows the limitations of the theoretical estimates.
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.
Shows the development of a procedure at Princeton University which involves an instrumented energy audit combined with a partial retrofit, and especially applicable to post-war single-family housing. This procedure is known as the `house-doctor' approach and is being tested in a 168 house experiment. Preliminary results show a 10-15% reduction in total use of natural gas following partial retrofit measures. Further retrofits based on house doctor observations led to a 20-25% reduction.
Assesses the efficacy of an engineered mechanical ventilation system in controlling indoor humidity in one of the HUDAC Mark XI houses. Develops a mathematical model of the home, which is used to demonstrate the interaction between outdoor humidity, infiltration and ventilation rates, and indoor moisture generation and their influence on indoor humidity levels. Discusses the operating effectiveness of the rotary heat exchanger and the energy saved through its use.
An experimental investigation of wind-induced pressure loads acting on two square-plan flat-roofed model structures (50ft and 225ft high in full scale) is described. Measurements of mean, peak and root mean square pressures acting on points and over larger roof areas have been made in turbulent boundary layer flow simulating wind over urban and open country terrains. Area loads on the roofs have been measured both by a pneumatic-averaging technique, and by using a large flush-diaphragm transducer.
Describes detailed experimental analysis of the low energy Plainevaux House with regard to:< 1. Air infiltration, measured by the decay rate of CO2 tracer gas< 2. Air tightness, measured by the fan pressurization technique< 3. The evolution of inside temperature in a period of no-heating< 4. The corresponding air contamination.
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