modelling

Describes the computerized instrumented residential audit (CIRA), a collection of building energy analysis programs designed for a wide variety of microcomputers. Covers methods and type of input, and types of output produced.

Describes an analytical model used to study the effects of air supply rates on the dynamics of an occupied space as related to energy consumption and occupant's comfort. Reviews the concept of Air Diffusion Performance Criteria (ADPI) and uses it to derive air movement control strategies to reduce energy consumption in buildings. Discusses the relationship between the air movement control strategies and passive thermal control strategies for energy efficient buildings.

Uses mathematical models for formaldehyde concentrations in 3 normal rooms in a single family house to estimate ventilation rates needed to maintain the formaldehyde concentration below the Danish recommended indoor standard (0.15 mg/m*3). It appears that in an initial period after the house is finished, a ventilation rate more than 10 times the recommended Scandinavian value (0.5air changes/hr) is needed to keep the concentration below the indoor standard.

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.

Describes a predictive model for air infiltration in residential structures. Uses wind speed and outdoor temperature data, along with selected building and site parameters to predict average infiltration. Presents long-term field validation results obtained in a portable test structure, together with long-term data from 3 unoccupied test houses at the Owens-Corning Technical Centre. Finds that the ratio between predicted and measured infiltration peaks near one in all comparisons. The estimated standard deviation of the ratios decreases with longer averaging times.

Gives a brief overview of energy-estimating procedures for energy conservation in buildings. States that most of these procedures are either too simplistic to provide the desired level of accuracy and comprehensiveness or they are too complex to gain widespread usage. Reports on the development of a comprehensive modified bin method for estimating building energy usage, created by the ASHRAE Technical Committee (TC) 4.7 for Energy Calculations. This procedure can lend itself for manual calculations and can be easily programmed into microcomputers.

Investigates the accuracy of the TWOZONE computer auditing program (used in analyzing the energy performances of residences) when used with home-owner supplied data. Compares actual energy consumption data collected from houses in New Mexico with estimates obtained from the TWOZONE model using input data from occupant questionnaires. Finds a high degree of variability between predicted and observed values, and concludes that much of the error introduced into the prediction is attributable to the qualitative nature of the data supplied by the respondents.

Looks at the requirements for computer model validation, especially in regard to predicting energy usage in buildings. Discusses the IEA project for comparing and validating several computer programs in this context. Describes the Glasgow commercial building monitoring project, which includes detailed measurement of temperature and air flow rates to provide data for model validation. States what type of data is needed for validation.

Describes the application of a model that relates infiltration to a quantity called the effective leakage area. This quantity scales the infiltration to local weather conditions and major design features of the house. The model isused to calculate the ratio of infiltration to leakage area averaged over the heating season, for a large number of sites in the US. It provides an effective tool for builders and designers who need a rational basis for assessing compliance with construction quality standards in ventilation.

Proposes a simple equation derived using a more complex theoretical model for use in the prediction of the infiltration performances of houses over a range of meteorological conditions. Initial comparisons have been made with the results from field measurements in a range of typical modern UK house types.