ZEMCH 2019 International Conference Proceedings April.2020 | Page 22
Building Plan Type
Building Orientation
Floor Area
Surface Area
System Characteristics
Rated Efficiency of Boiler
Boiler Type
Use of Aux. Heating Devices
# of Air‐con.
COP of Air‐con.
Occupant Characteristics
Family Size
Occupant Density
# of Under 8
# of 8‐19
# of 20‐64
# of Over 64
# of Employed
Heating Set T
Cooling Set T
NS
NS
NS
0.280 NS
NS
NS
0.341 NS
NS
NS
0.010 NS
NS
NS
NS NS
NS
NS
NS NS
NS
NS
NS
NS
NS
‐32.315
‐
‐ NS
NS
‐0.265
‐
‐ NS
NS
0.043
‐
‐ ‐
‐
‐
NS
NS ‐
‐
‐
NS
NS ‐
‐
‐
NS
NS
NS
NS
NS
NS
NS
NS
NS
8.164
‐ NS
NS
NS
NS
NS
NS
NS
0.517
‐
0.398 NS
NS
NS
NS
NS
NS
NS
0.000
‐ NS
30.711
2.155
NS
NS
NS
0.461
‐
NS NS
0.339
0.459
NS
NS
NS
0.242
‐
NS
0.486 NS
0.013
0.001
NS
NS
NS
0.022
‐
NS
Adjusted R²
F‐statistics
p‐value
9.586
0.000
11.70
0.000
NS: not significant in the stepwise multiple regression model.
3.1.2. Determinants of EUI for cooling
The stepwise regression result for the EUI for cooling is given in Table 1. Compared to the case of
heating, only occupant characteristics have significant influence on the EUI for cooling. Not
surprisingly, occupant density is highly correlated with the EUI for cooling. As it increases by 0.01
person/㎡, the EUI for cooling increases by 0.307 kWh/(㎡∙y). Among the age groups, only the children
under 8 has a significant impact on the EUI for cooling. An increase in the number of children under 8
increases the EUI for cooling by 2.155 kWh/(㎡∙y). It is considered that their impact on the EUI for
cooling is significant because they are more active, usually staying at home all day, and more sensitive
to high indoor temperatures compared to other age groups. In addition, an increase in the number of
employed residents increases the EUI for cooling by 0.461 kWh/(㎡∙y). It may imply that households
with higher income are willing to pay for electricity bill for cooling with air‐conditioners. Comparing
the standardized beta values shown in Table 1, it is found that number of children under 8 (0.459),
occupant density (0.339), and number of employed residents (0.242) affect the EUI for cooling in the
sequence.
It was found that variables such as surface area and set temperature have no significant
relationship with the EUI for cooling unlike the EUI for heating. This can be explained by the
operational natures of heating and cooling. Heating is often operated continuously at a set temperature.
On the other hand, cooling with air‐conditioners is often operated intermittently only when occupants
need. Thus, the EUI for heating is largely influenced by house size (e.g. surface area, etc.) and set
temperature, while the EUI for cooling is largely influenced by occupant characteristics.
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ZEMCH 2019 International Conference l Seoul, Korea