Paper Conference

Proceedings of ASim Conference 2014: 2nd Asia conference of IBPSA-China, Japan, Korea


Research on Temperature and Relative-Humidity

Ryotaro Iwayama, Akihito Ozaki

Abstract: In Japan in recent years, the Law Concerning the Rational Use of Energy was revised, so adiabatic airtightization of new residential housing has spread, and adiabatic repair is required in existing residences. Stock housing is increasing, especially in RC collective housing, therefore the improvement of energy-saving performance and efficient utilization through renovation are required. However, the effect and expense of adiabatic repairs on existing residences are not well-known, and has not resulted in positive adoption. Although the performance gain by adiabatic repair is estimated by a specification standard, thermal loss coefficient, etc., solar-radiation-heat acquisition, ventilation, an internal heat generation, internal humidity generation, etc. are disregarded. Dew condensation and mold caused by adiabatic airtightization also have been generating damage, so a measure for lowering high humidity is needed on the occasion of adiabatic repairs for existing residences where there is anxiety about a shortage of ventilation. In previous research, the effect of room temperature rise and heat load reduction by adiabatic repairs has been reported based on measurement surveys and numeric simulation. However, factors which influence comfortable nature, healthy nature, and durability, such as dew condensation and the temperature and relative humidity change of each part of a building are disregarded. So, in this research, adiabatic repair of various patterns in the existing collective housing is assumed, and "THERB for HAM", which is an analytical tool of construction thermal environment and heat load, was used for the numeric simulation. Also, we predicted compound movement of the heat and moisture of the building as a whole in detail, and we investigated the influence on the energy-saving effect and temperature and relative humidity environment by adiabatic repairs. As a result, it was shown that adiabatic repair is effective in the improvement of the indoor thermal environment and energy saving. However, there was a risk of promoting dew condensation on the window and outer wall of the non-repaired part in a non-heated room. So, there is a risk of degrading durability in especially partial repairs, therefore it is unveiled that these renovations need to be planned carefully.
Keywords: RC collective housing, Renovation, Numeric simulation, Dew condensation, Energy saving, Temperature-and-relative-humidity change
Pages: 515 - 522