Energy efficient steel buildings with better thermal insulation to reduce transmission losses are now being built in Sweden. Examples of structural design are given to minimise the influence of thermal bridges. A method for the calculation of such heat losses is presented. Principles for airtightness to reduce air leakage of buildings are discussed, special details and material requirements are given.
A brief synopsis of recent analytic and experimental studies is given. Conclusions are that convective transfer of water vapour into an attic from the living space below often transports more moisture than diffusive transfer through the ceiling construction. Large quantities of moisture are stored in the roof sheathing during warm spring and summer periods. Solar loading during mild winter periods can produce desorption of moisture from the sheathing. This paper reviews the formulation of mathematical relationships among physical parameters governing moisture transfer within attics.
Describes the physics of moisture in the home. Suggests four basic strategies for dealing with excess moisture buildup in the home: 1) minimise the entry and release of moisture, 2) protect building components with vapour barriers, 3) remove water vapour with ventilation or dehumidifiers and 4) raise theinside surface temperature of windows.
Test structures were constructed near Madison, Wis, USA and Gulfport, Miss, USA for exposure of eight types of insulated wall panels at controlled indoor conditions and typical outdoor weather conditions. Panels were instrumented with moisture sensors and tested without and with penetrations (electrical outlets) in the indoor surface. Continuous internal vapour barriers effectively prevented cold weather condensation in all panels. Installation of an electrical outlet changed moisture patterns in both the cold winter climate and the hot, humid summer climate.
Lists the basic sources, mechanics, and problems of moisture in houses in the USA. The NCAT paper covers 1) why and where most moisture problems are likely to occur, 2) symptoms, causes and the range of possible solutions to excess moisture, 3) techniques used to remedy moisture problems, including vapour barriers, ventilation, drainage improvements and basement and foundation treatments and 4) a generalised moisture audit methodology, including tests and equipment needed.
The effect of small aerosol particles and the effect of air cleaning devices on the behaviour of the decay products of radon have been studied. The long term measurements in a one-family house have shown that the behaviour of the decay produc
In a previous paper it was found that the number of persons occupying aroom, or the air space per occupant, is a very important factor affecting theper capita outdoor air supply for the control of body odors. In a room with a net air spac
The work to be described here is an elaboration of Lehmberg's preliminary experiments. The object was to study the general problem of ventilation odours under normal conditions, comparable to those in schoolrooms, offices, homes and the like with the possibility of establishing ventilation requirements for various groups of individuals, including grade school children and adults, under representative winter and summer conditions. Three methods of odor control were studied dealing with personal sanitation, ventilation, and air washing.
Measurements reported in this paper demonstrate the increase in heat transfer due to convective air flow that can occur in wood-frame walls containing air-permeable mineral wool insulation with air spaces in contact with both sides. The effect of this air interchange between the air spaces increases with increasing temperature difference, air space height and air permeability of the insulation. Use of mid-height blocking and higher density insulation thus resulted in some reduction in the heat flow through the insulation, although convective effects were still significant.
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