Research and Study on Electric Housing in Northern Regions Using Heat Pumps

Amid growing concerns over environmental issues like global warming, the implementation of energy conservation policies is being promoted. Among other things, consumer-use energy conservation is an urgent issue due to its increase in energy consumption. Characterized by a cold-region use, Hokkaido’s housing is designed with improved heat insulation and airtight properties after several revisions of energy saving standards. Despite this technological breakthrough, the annual heating energy consumption per household, taking into account the level in existing housing as well, accounts for over 50% of the total household energy consumption, which is 3 times the national average including warm regions.

Thus, the introduction of a high-efficiency heat pump system with favorably environmental and energy-saving properties, not only in new housing but also existing housing in cold regions, is expected to control the increasing consumer-use energy consumption.

In this study, the following approaches are taken to address these issues.

• Discussion of housing and equipment specifications so as to introduce heat-pump hot-water heat source equipment from field survey results of hot-water heating systems in existing housing
• Discussion of a heat pump system suitable for housing specifications from thermal environment field survey and simulaiton results in radiantion (hot-water) and convection (hot-air) heating systems

Based on the operational state and actually obtained data at room temperature of hot-water heating systems (double hot-water piping systems) in detached houses (meeting next-generation energy-saving standards, coefficient of heat loss less than 1.6W/m2･K, revised in 1999), the applicability of existing heat-pump hot-water heat source equipment was examined.

To find out the conditions of housing with such applicability, heating equipment specifications were assessed with 2 factors (see Fig.1).

As shown in Fig.1 (shaded region), it was found that heat pump applicability conditions are the sufficient total capacity of hot-water panel heater placed exceeding the housing design load and the installation of a hot-water panel heater whose capacity is sufficient in main room (e.g. living room) for users to stay for a long time.

Fig.1 Range of applicability of heat pump hot-water heat source equipment in detached houses