EVALUATION OF ENERGY CONSUMPTION AND HEALTH HAZARDS IN RESIDENTIAL HOUSES

Part. 1 Investigation of high insulation and air tightness in detached houses using time series heat load simulation

Abstract

 Since many of residential houses in Japan were built before 1980, they have very poor thermal insulation. With poor thermal insulation specification, these houses could consume much amount of energy for heating. In addition to that, indoor thermal environment in winter could be so poor especially in non-living rooms such as bathrooms. Low temperature in houses could cause occupants' higher blood pressure, heat shock, and many other diseases.
 Energy consumption and health hazards in a model house were investigated using a heat load simulation tool in this research. The simulation tool were capable to show that annual heat load, energy consumption for HVAC, and room air temperatures of every five minutes in the house in several cases which differed thermal insulation performances. We confirmed that, in general, the higher insulation level of the model house were associated with the lower health hazards and reduce energy consumption for heating. We also indicated that effective heating methods enable to reduce health hazards with a small amount of additional energy.
 In Chapter 1, we referred to previous studies relating to this research. There are many research papers discussing topics, thermal insulation, thermal environment in houses, and health respectively, however, most of the preceding papers are not dealing with the topics integrally.
 In Chapter 2, we indicated that input condition for simulation case studies. We chose the model house plan for the simulation which met ‘Standards of Judgment for Residential Construction Clients’. The simulation conditions include not only various insulation performances, but also several heating methods such as heating sanitary space just before bathing time.
 In Chapter 3, we proposed an index that indicated health hazards. This index was provisional since the relationship between indoor temperature and occupant's health should be reconsidered by further actual health hazards study results.
 In Chapter 4, we showed results of the case studies. Indoor temperature with no insulation reached about 5°C in winter morning. The case that had enough insulation performance to meet the Japanese energy saving standard, the room temperature did not get below 10°C. In order to keep the room temperature above 15°C, insulation level needed to be as high as the German energy saving standard. However, the temperatures of non-heating rooms did not get higher in some cases which had implemented partial thermal insulation renovation of only at LDK (a living room, dining room and kitchen) or other rooms.
 Energy consumption for heating could reduce by high insulation level. Heating energy of no insulation house was more than twice as much as the house which had enough insulation level that met the Japanese energy saving standard. In order to reduce health hazards, heating non-heating rooms in short time was as effective as improvement of thermal insulation performance. By heating the sanitary space and bedroom, it enabled to improve the health hazard index with a small amount of additional energy.