S. Yoon et A. Hoyano, Passive ventilation system that incorporates a pitched roof constructed ofbreathing walls for use in a passive solar house, SOLAR ENERG, 64(4-6), 1998, pp. 189-195
This paper describes a natural ventilation system that incorporates a pitch
ed roof constructed of Breathing Walls for use in a passive solar house. Th
e Breathing Wall is expected to solve the inherent contradiction that exist
s for a building that is open to the outside air, in which a balance in the
indoor air/moisture conditions is maintained, but energy efficiency is low
. In other words, the use of Breathing Walls can provide a healthy and comf
ortable environment at higher energy efficiency in a passive solar house. I
n the present study, we experimentally evaluate the effects of roof pitch a
n the heat recovery capability and the occurrence of internal condensation
within the Breathing Wall, using a simulation of the ventilation rate of a
natural ventilation system. The effective opening area per unit area requir
ed to provide sufficient air change capability, i.e., 0.5 AGH, even for zer
o wind velocity, was determined to be 10 and 5 cm(2)/m(2) for pitches of 26
.5 degrees (Pitch 1) and 45 degrees (Pitch 2), respectively. Furthermore, a
t the maximum predicted wind velocity of 10 m/s for Pitch 1/2, even though
the outdoor air temperature is 5 degrees C, the temperature of the indoor-m
ost air reaches 13.2/12.5 degrees C, corresponding to a heat flux of;approx
imate to 128/158 W/m(2). No internal condensation occurs, even at the maxim
um pressure differential, which corresponds to a wind velocity of 10 m/s ac
ross the wall of the Pitch 1/2 model, when a Breathing Wall having an openi
ng area per unit area of 11.3 cm(2)/m(2) was installed in the ventilation s
ystem. (C) 1998 Elsevier Science Ltd. All rights reserved.