Fusao Hasegawa

Optimum use of solar energy techniques in a semi-underground house: First-year measurement and computer analysis☆

Abstract In order to obtain fundamental information on techniques for the optimum use of solar energy in a semi-underground house, a twin-type test house was constructed on the campus of Tohoku University in September 1984. The test house has two rooms, with a south-facing window above the ground surface and a corridor situated between the two rooms. Insulation 10 cm deep and 1.35 m wide was installed horizontally 30 cm below the ground surface, surrounding one room of the house. The other room is not insulated. During the first year, all windows were insulated with weather shutters to avoid disturbing the heat gain due to solar radiation. As a result, the yearly room temperature swing varied °C less than the temperature swing of outdoor air. The air temperature in the insulated room was 1.2°C higher in the winter and 0.5°C lower in the summer than in the room without insulation. The influence of various thermal insulation formations in the earth around the house on room temperature fluctuation and heating and cooling loads was calculated using the two-dimensional finite element method. Calculations were performed hourly for a year under standard climate conditions in Sendai, Japan.

Investigation of indoor thermal environment, air quality, and energy consumption in new detached houses of wood-frame construction in a small city in Japan

The authors investigated indoor thermal environment, airtightness, indoor air quality, and energy consumption in thirteen new houses of wood-frame construction in a local city of Japan in the winter of 1985. All houses had thermally-insulated walls, ceilings, and floors, except for one house which had a concrete floor without insulation under the floor. Eight houses had concrete floors on the first level of the structure. Seven houses out of eight had hot-water pipes embedded in the concrete for floor heating and thermal insulation under the floor on the grade. Three houses out of seven also had fan coil units in the bedrooms on the second floor. The six other houses without floor heating had oil or gas local space heaters. The authors found differences in temperature profiles between the houses with floor heating and those with space heaters. The effective leakage area per floor area obtained by the fan pressurization method was distributed from 3.8 to 16 cm{sup 2}/m{sup 2}. The concentration measurements of CO{sub 2} and NO{sub 2} in the living rooms showed that the two houses with unvented oil space heaters were more polluted than the other houses. The total annual amount of energy consumption was distributed frommorexa0» 46 to 100 GJ.«xa0less