Examines the possibilities of achieving energy-efficient ventilation systems in naturally ventilated homes (which include the use of intermittent extract fans in individual rooms). Discusses factors affecting energy efficiency. Treats general design requirements for mechanical and natural ventilation systems. Discusses the characteristics of natural ventilation systems, including leakage, weather and window opening. Compares natural and mechanical systems. Provides suggestions for natural ventilation design.
Describes a scale model test technique designed to estimate building ventilation flow rates due to wind as a function of its primary variables. Use of this method is illustrated by its application to the determination of wind-induced ventilation flow rates in earth-bermed, above-ground fallout shelters. Shelter models with 3 different sets of wall openings are tested over a range of relative wind angles varying from 0 to 90 degrees and wind speeds from 2.25 m/s to 6.75 m/s. Helium filled soap bubbles released in the approach wind boundary layer trace the flow through the buildings.
Illustrated booklet for the layman on heating and ventilation in housing which discusses the following: oil heating, wood firing, electrical heating, district heating, heat pumps, solar collectors for domestic hot water, ventilation systems, natural ventilation, mechanical ventilation, push-pull systems, heat exchangers, fans. Appendix discusses measurement of oil-fired system efficiency.
Distinguishes the problems of designing natural ventilation systems for summer and winter conditions and discusses in detail the objectives, methods and some field studies directed towards the solution of winter ventilation problems.< Describes experimental work conducted in a low-energy house equipped with adjustable slot ventilators in the window frames. Both tracer gas decay methods and pressurization tests indicate similar increases of air flow when the ventilators are opened.
Describes a programme of ventilation measurements performed on a group of energy efficient houses built in the mid-1970's and situated in Abertridwr, S.Wales. Pressurization, tracer decay and British Gas autovent techniques were employed. Results show satisfactory whole-house ventilation rates (0.5 ac/h), but the living room and bedrooms had very low ventilation rates. Some cases showed serious condensation. "Trickle" ventilation installed in 18 of the houses improved internal ventilation patterns and condensation levels were substantially reduced.
Traces the relationship between ventilation needs and methods and the growth of civilization. Describes the development of ventilation methods and assessment of air quality, especially since the Industrial Revolution. Questions whether currently accepted ventilation criteria are still valid, andsuggests that ventilation is only one of several means of ameliorating the internal environment.
Describes a simple method of controlled ventilation comprising an extract system and air inlets. The extract system is effectively a flue connecting to vents in the kitchen and bathroom and relying on thermal differences and the wind to create air flow, air enters the house via slot vents over windows. Theproposed system has been installed in a timber framed house.
Examines several ventilation strategies in tight houses for both impact on the total ventilation and effect on the energy balance of the system. Uses the single-zone infiltration model developed at LBL as part of the calculation of total ventilation load. Strategies covered include natural systems such as ventilation stacks as well as mechanical systems such such as air-to-air heat exchangers and exhaust fans with and without heat pumps.
Reports on the metabolic CO2 method for ventilation measurement which has been extended from mechanically ventilated rooms to naturally ventilated ones. The analysis, which under some circumstances is also relevant to tracer gas decay measurements, allows assessments of the individual incoming flows of air.
Uses a similitude approach to develop predictive graphs for the ventilation rate due to the stack or chimney effect. Uses a half scale model of an open side wall structure with a continuous and restricted open ridge, and finds that:< 1. Ventilation rate is approximately proportional to ridge outlet width< 2. Outlet Reynolds number response ie ventilation rate to changes in Grashof number is a function of the ratio between building height and ridge width.
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