Reports tests made on a mobile home to evaluate its thermal performance. Describes home, instrumentation and test procedure. Gives energy consumption as a function of indoor-outdoor temperature difference. Finds that oversized heating plant resulted in low seasonal operating efficiency. Air infiltration was measured using pressurization technique and SF6 as a tracer gas. The latter showed that operation of the heating plant induced higher air infiltration rates. Reports thermographic survey of interior surfaces which showed air paths formed by wrinkles in the surface insulation.
Outlines a number of experimental approaches for determining the energy consumption of a building, with emphasis on air infiltration. The combined use of depressurization of the house and infrared scan permits the location of "bypass" vents through which warm air is leaving the structure. Describes several types of bypasses and evidence for their widespread existance is documented. Discusses the side effects of retrofitting these and other energy loss sites with regard to fire safety, air quality and moisture.
Treats report investigating results of door opening in terms of energy loss and changes to indoor climate. In 3 sections. Treats: 1) general regulations and manufacturing standards and relevant swedish building regulations concerning airtightness, thermal insulation and functional aspects. 2) Flow of air under different conditions such as pressure differences caused by variations in temperatures and wind. 3) Describes laboratory experiments using 1:10 scale fluid model.
A supply of fresh air is necessary in any dwelling to ensure a comfortable, safe and hygienic environment, but the heat loss to this air, during the heating season, may represent a substantial proportion of the total heat loss. This points to the need forgreater control of domestic ventilation, either by using a mechanical system or by better design for natural ventilation. This paper touches upon both of these possibilities. Gives simple method for assessing approximately the possible reduction in heat loss achieved by the use of a mechanical ventilation system.
States that current methods of estimating heat demand of buildings are very inaccurate, and so large safety margins are used which usually result in overestimating the necessary heating plant capacity. Describes computer program developed to improve the accuracy of heat demand calculations. Gives formulae used in the program for calculating heat demand, pressure conditions and air flow within the building. Gives example of the use of the program to calculate the effect of wind on an eight-storey residential building.
Outlines the principles of infrared thermography and describes the equipment. Reports investigation at the National Swedish Institute for Material Testing into the use of thermography. Finds that the method should primarily be used as a relative method for plotting of building faults on external walls and for qualitative judging of their nature. It is not suitable for quantitative determination of the heat resistance of walls.Gives typical thermograms prepared using a test wall to which artificial defects were added.
Reports on the air leakage characteristics of the exterior walls of eight multi-storey office buildings in Ottawa. Results of the measurements taken are given and a method for calculating infiltration rates caused by stack action has been developed andis applied to heat loss calculations using the measured wall leakage values.
Points out that increased levels of thermal insulation in dwellings make ventilation heat loss an increasingly significant proportion of total dwelling heat loss and of great significance for sizing heating installations and selecting their control equipment. Treats attempts to reduce ventilation loss by specifying greater tightness of building structures, especially windows.
Compares the new draft standard with the 1959 original. More sophisticated mathematical methods and meteorological data processing has necessitated the revision. The new standard incorporates SI units, uses resistance calculations and develops computer compatible stationery
States heat load on buildings due to wind is dependent on the shape of building, wind direction and wind speed. Gives theoretical calculation for the heat loss due to wind based ongerman standard DIN 4701. Discusses fundamentals of fluid dynamics and the practicalities of wind tunnel tests. Recounts tests made of a block of flats in Munich. Pressure distribution due to wind was determined by a wind tunnel test on a model, giving c-profiles for different wind directions.
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