Shin-ichi Matsumoto

Five-year measurements of thermal performance for a semi-underground test house

Abstract In order to obtain fundamental data on the thermal performance of a semi-underground room, a twin-type test house was constructed on the campus of Tohoku University in September 1984. The test house has two rooms with south-facing windows above the ground surface, and a corridor between the two rooms. The floor level is 1.3m below the ground surface. Thermal insulation 0.1m deep and 1.35m wide was installed horizontally around the room on the east at a level 0.3m below the ground surface. The room on the west has no such “horizontal” insulation. Five-year measurements of air temperatures in both rooms, soil temperatures around the rooms, energy consumption for space heating, and so forth were made in four different situations. An experimental study found that horizontal insulation was effective in reducing the annual temperature fluctuation of indoor air, and in reducing the heating load. These effects, which were also analyzed from the viewpoint of heat balance in the room, were verified by computer calculations based on the two-dimensional finite element method.

Thermal performance of three deep basements: a comparison of measurements with ASHRAE fundamentals and the Mitalas method, the European standard and the two-dimensional FEM program

Abstract The comparison of four methods for the calculation of deep-basement heat loss is presented along with measured data for three basement types. The Mitalas method was found to give results in best agreement with measured data followed by the finite element method (FEM) program, the European Standard and the ASHRAE Fundamentals method. The studied methods, with the exception of the European Standard of which the physical background was unknown, were chosen because each of them is also representative of a particular physical model of decreasing complexity in the above order. Therefore, differences in presented results yielded by these methods provide insight about differences one can expect when using 3-D, 2-D and/or 1-D physical models for the calculation of deep-basement heat loss. The sensitivity of studied methods to input parameters representing various thermal properties of soils and temperature boundary conditions was investigated also.

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.

Thermal comfort in passive solar earth integrated rooms

Abstract Presented are the two-year temperature and relative humidity measurements in semi-underground rooms in Sendai, Japan, and one year measurements in fully earth integrated rooms in Brhlovce, Slovakia. The monthly mean and daily mean spring and summer data are shown together with Predicted Mean Vote (PMV) indices. Similar data on air temperatures were found as in the previous studies. However, the more complex evaluation of thermal comfort using PMV index helped to determine that fully earth integrated rooms without insulation and proper design of transparent constructions may be cold in spring and even summer in a temperate climate. This finding is different from previous studies, which stated that earth integrated spaces in temperate climates were comfortable on the basis of air temperatures alone. The degree of earth integration, the level of insulation of the earth in contact with construction, and the size of south oriented transparent construction were found to be the key parameters of passive solar earth shelter design and conclusions were drawn regarding their implementation in various climates for optimal control of spring and summer thermal environment.

CASE STUDY ON APPLIANCE CHARACTERISTIC OF ENERGY CONSUMPTION FOR RESIDENTIAL BUILDINGS IN AKITA PREFECTURE

In order consider the efficient residential energy conservation, measurements on energy consumption for four houses in Akita Prefecture have been conducted for two years. Annual energy consumptions classified by energy source, end-use, and appliance, and also daily profiles of energy consumptions for lighting and others were shown. In conclusion, total energy consumption for lighting and others showed a small seasonal fluctuation, excepting that for refrigerator and “washret”. Energy consumption fluctuations for some appliances in some houses had a different tendency depending on weekday and holiday. Energy consumption is related to appliance performance, energy usage and residents lifestyle.