Literature Review on Building Envelope, Heating and ... - Beeshive.org

consumption and CO 2 emissions associated with electricity and heating of the house over
its service life are much greater than the energy consumption and CO 2 emissions related
to the manufacturing and transport of building materials. Therefore, in this regard, the
authors argued that, a light-gauge steel building envelope system possibly reduces the
environmental impact due to the operation of the building. Computed heating energy
consumption of the energy-efficient steel frame house was 40% to 50% lower than the
energy consumption of a house constructed according to the Finnish building code
standards.
Aromma (1999) and Sandberg and Nieminen (1997) concluded that using perforatedweb,
light-gauge steel did not increase the energy consumption of buildings, and allowed
for possibly reducing the environmental impact due to the operation of the building. A
perforated web light-gauge steel building envelope would provide energy-efficient and
environmentally friendly building envelopes for the cold climate of Finland. The extra
insulation layer on the outside of the steel stud wall solves the thermal bridging
deficiency of the steel.
Japan
Yoshino (1991) discussed design strategies for houses in the cold-climate regions in
Japan (Hokkaido District and the northern area of the Tohoku District). Yoshino also
reviewed climatic characteristics, thermal performance of the building envelope, heating
and ventilating equipment, energy consumption, and cold weather-related house
problems. The cold-climate regions in Japan are characterized by 3000ºC to 4500ºC days
(heating-degree-days base 18ºC), which is comparable to the southern regions in Canada.
The average outdoor temperature in January is –5ºC (23ºF). The seasonal northwest
wind, laden with moisture, is intercepted by mountain ranges and bring heavy snow to the
region along the Sea of Japan. Dry air then passes over the mountain and results in clear,
sunny weather in areas along the Pacific Ocean. The summer is hot and humid where the
mean outdoor temperature is 24ºC (75ºF), and the mean relative humidity is 80%. Thus,
Yoshino recommended that the summer climate should also be taken into consideration
when designing houses in such cold climate regions along the Pacific Ocean.
The average floor area of houses in Japan’s cold regions ranged from 118 m 2 (1274 sq.
ft.) to 150 m 2 (1616 sq. ft.). The space heating equipment used in most houses is a large
kerosene space heater with a chimney for exhaust. The thermal insulation level varied
between cold regions. Table 4 lists the R-value range of insulation used in the so-called
standard Japanese houses.
Double-pane windows with an air space more than 10 mm (3/8 in.) are used in most
houses. Single-glazed windows are common in some regions. Plastic and aluminum
sashes are used in 45% of the houses. The air tightness of the building envelope,
expressed in terms of the equivalent leakage area per floor area, ranged from 0.27 to 20
cm 2 /m 2 (0.003% to 0.2% of floor area). The lower air-tightness value, 0.27 cm 2 /m 2 , is
comparable to the Canadian R-2000 house standards.
PERD-079: Task 2 - <strong>Literature</strong> <strong>Review</strong> 59