Michiya Suzuki

Estimation of life cycle energy consumption and CO2 emission of office buildings in Japan

The purpose of this study is to quantify the total amount of energy consumption and CO2 emission caused by the construction, operation, maintenance, and renovation of office buildings in Japan. In order to quantify the life cycle energy consumption and CO2 emission of a building, it is necessary to obtain an estimate of the total quantity of domestic products and services used directly or indirectly (including the repercussion effect of the economy) during the life cycle of the building. The Input/Output (I/O) Table of Japan is used to calculate the total domestic product and then energy consumption and CO2 emission are estimated by using energy consumption and CO2 emission data for unit production of various categories of industries.

The estimation of energy consumption and CO2 emission due to housing construction in Japan

Basic sector classification Input/Output Tables of Japan (Research Committee of International Trade and Industry, Tokyo, Japan, 1988) were applied to quantify the total energy consumption and CO2 emission including direct and indirect effects due to the construction of various types of houses. As a result, energy consumption for construction is calculated as 8–10 GJ per square meter of floor area for multi-family SRC (steel reinforced concrete) houses, 3 GJ for wooden single-family houses, 4.5 GJ for lightweight steel structure single-family houses. CO2 emission resulting from construction is 850, 250 and 400 kg/m2, respectively.

The estimation of energy consumption and amount of pollutants due to the construction of buildings

In this paper, the total energy consumption and environmental pollution caused by construction are quantified using the Inter-Industry Relations Table in Japan. The size of the six buildings which are evaluated in this study vary from 1502 m2 to 216 000 m2. The major results are as follows: • total energy consumption caused by construction of office buildings is 8–12 GJ/m2 of floor area; • CO2 production is 750–1140 kg, SO and SO2 720–1430 g, NO and NO2 700–1140 g, dust 70–130 g per m2 of floor area; • the construction cost per square meter of floor space is proportional to the energy consumption and production of pollutants; • Structural work is shown to be high in energy consumption and CO2 exhausted per unit cost of construction; industrial waste exhausted in finishing work is higher than two other categories of the work (structure and equipment); equipment work is shown to be relatively low in energy consumption, CO2, NO, NO2 and industrial waste produced.

THERMAL PERFORMANCE TEST AND THERMAL ENVIRONMENT SURVEY OF CEILING RADIANT COOLING SYSTEM

An air conditioning system using ceiling radiant cooling panels and personal floor diffusers is designed. It is assumed that ceiling radiant cooling panels remove a cooling load and personal floor diffusers giving both air-conditioned outlet air and an air current feeling for individuals. The experiment facility for the system is constructed, and the thermal performance test and the thermal environment survey are performed. This paper reports the results of the thermal performance test and the thermal environment survey of the system, and shows that the system removes a cooling load properly and can provide the comfortable thermal environment for individuals.