Topics

Support for the development of an evaluation method
for energy saving in houses concerning the EnergySaving Standard

MIURA Hisashi (Dr.(Eng.)), Senior Research officer,
MIKI Yasuhiro (Dr.(Eng.)), Senior Research officer
Housing Department, Residential Environment Planning Division
NISHIZAWA Shigeki (Dr.(Eng.)), Senior Research Officer
Building Department, Environmental and Equipment Standards Division(Key words) Energy conserving, assessment, refurbishment, housing
1. Evaluation of energy saving for newly builthouses
A new standard for the evaluation of energy
saving of newly built detached houses wasintroduced in April 2009 (Top Runner Standard forHouses). In this standard, in order tocomprehensively evaluate diversifying energy
saving methods such as the solar water heater andheat pump technologies, energy saving performanceis evaluated based on the primary energy
consumption instead of the thermal envelope
performance. Primary energy consumption can becalculated by the equation in the figure. In addition
to correctly evaluating the envelope performance, itis therefore important to evaluate the efficiency ofthe equipment and appliances such as DHW
systems, ventilation systems.
2. Evaluation of the efficiency of residentialequipment and appliances
For example, gasoline mileage depends on how
to the vehicle is driven. Similarly, the efficiency ofthe equipment and appliances is largely dependentof the operating condition and usage of theoccupants, NILIM has performed a study to clarify
which parameters effect the efficiency of theequipment and appliances in houses under the realcondition, and developed a framework for theevaluation of energy saving.
Related research projects started in 20011), andthrough the recent research results2), the research
results are used in the calculation of the energy
saving performance in Top-Runner Standard forHouse. The framework of the evaluation for thehousing equipment and appliances has already been
completed, and the research continues in order todevelop more accurate assessment methods forparticular technologies.
3. Evaluation of energy saving renovations ofexisting detached houses
As the effective utilization of the existing houses
has become important in recent years, it is now also

Primary energy
consumptionLoad
Efficiency of equipment(machinery)

Load is:Demands necessary for residents to lead stable lives; forheating/cooling, it is the heat required for heating and theheat which must be removed for cooling, for ventilation, itis the quantity of air, for supplying hot water, it is therequired quantity of hot water, and for lighting, it is therequired brightness (luminous intensity).

Figure Concept of Calculation of Primary
Energy Consumption
necessary to develop the energy saving potential forrenovating existing houses in addition to developing
the energy saving potential for newly built houses.
NILIM is therefore carrying out a research projectin order to develop the evaluation method forenergy saving potential of renovations3). To
calculate and compare the primary energy
consumption of the houses before and after
renovation, we are developing calculations orcalculation rules such as, [1] evaluation of thethermal performance for the construction unique tothe renovation such as windows replacements, [2]evaluation of the partial renovation such as
renovating only the envelope of a living room, and[3] evaluation of the thermal and energy
performance of the existing envelope andappliances whose performance is difficult to clarify
by some inspections. This research will be used forsome kind of the standards for energy saving
renovation.
[References]1) Ministry of Land, Infrastructure, Transport andTourism
Comprehensive
TechnologicalDevelopment Project, Development of Low
Energy and Resource Saving Technologies forAutonomous Building and Urban System (2001- 2004).
2) For example, Environment Research &Technology Development Fund, Research on

the Development and Promotion of Energy
Saving Technologies on Houses (2003- 2005)
3) DevelopmentofEnergy
Consumption
Performance Evaluation Methods for Various
Types of Houses (2010 - 2012)
http://www.nilim.go.jp/lab/icg/4_shouenekaishuu.htm- 2 -