Paper 8
Estimation
of the Effectiveness of Cross Ventilation as a
Passive
Cooling Method for Houses
Takao
Sawachi1, Shigeki Nishizawa1, Hiromi Habara2
and Hisashi Miura2
1
National Institute for Land and Infrastructure Management, Japan
2
Building Research Institute, Japan
Abstract
The effectiveness of
various methods for saving energy and improving the indoor environment in
buildings depends upon the building conditions under which those methods
are applied. To find better design solutions in such situations, designers
or building owners need to make reference to quantitative information so
that they can choose appropriate methods, which fit to the design
conditions. These include data such as climate, surrounding environment,
construction, occupants’ lifestyle and economic constraints. Passive
cooling by natural ventilation is one of the promising methods to achieve
thermal comfort, but its effectiveness should be clarified, especially in
relation to saving energy. In
this paper, an integration of research outputs on cross ventilation is
made in order to determine the reduction of cooling energy that can be
achieved. This is undertaken by considering a series of questions and, by
reviewing existing knowledge, finding appropriate answers. Existing
research outputs include the prediction of wind pressure and discharge
coefficients as well as the behavioural model of window opening by
occupants, the application of coupled heat and airflow simulation tools,
and the actual energy efficiency of air conditioners under use. Through
such integration it is possible to estimate the sensitivity of cooling
energy resulting from errors in the discharge coefficient and the wind
pressure coefficient and to determine the necessary accuracy for those two
parameters.
Key words: natural
ventilation, cross ventilation, passive cooling, residential building,
wind pressure, discharge coefficients.
References
Ishihara M: (1969) “Design of
Building Ventilation”.
Asakura Publishing Company, Tokyo.
Katsuta C and Sekine T: (1961) “Experimental study on ventilation by the
roof monitor. Transactions of Architectural Inst. Japan, (68),
pp116-120.
Knoll B, Phaff J and de Gids W: (1995) “Pressure Simulation Program”, Proc.
16th AIVC Conference.
Kurabuchi T, Ohba M, Fugo Y and Endoh T: (2002) “Local similarity method
of cross–ventilation part 1 modeling and validation, The 8th Int.
Conf. on Air Distribution in Rooms, pp613-616.
Orme M, Liddament M and Wilson A: (1994) “numerical data for air
infiltration and natural ventilation calculations. AIVC Technical Note
44.
Richter, H.
(1958) Rohrhydraulik, 3 Aufl., 172.
Sato K, Sawachi T, Maruta E, Seto Y, Hoyano A, Takahashi Y: (2006) “study
on the prediction accuracy of wind direction and speed above a buildings
and the wind pressure on its wall by using hourly wind data at local
meteorological observatory”. J.
Environ. Eng., AIJ
(603), pp33-39.
Sawachi T, Narita K, Kiyota N, Seto H, Nishizawa S. and Ishikawa Y: (2004)
“Wind Pressure and Airflow in a Full-Scale Building Model under Cross
Ventilation”, The International Journal of Ventilation, 2,
(4), pp343-357.
Sawachi T, Maruta E, Takahashi Y and Sato K: (2006) “Wind pressure
coefficients for different building configurations with and without an
adjacent building”, The International Journal of Ventilation, 5,
(1), pp21-30.
Sawachi T, Maruta E, Takahashi Y and Sato K. (ed.): (2007)
“Report of the Research Project on Wind Pressure Coefficient for Natural
Ventilation Design. Cp Task Group”.
Shioji M, Yamane K, Moriguchi K and Ikegami M: (1991) “Visualization of
turbulent eddies in a free jet by a laser sheet method”. Transactions
of Japan Society of Mechanical Engineers, Series B 57, (544),
pp26-32.
Shoda T and Goto S: (1956) “Effects of exposure on ventilation of
buildings”. Transactions of Architectural Inst. Japan. (53),
pp80-87.
Swami M and Chandra S: (1988) “Correlations for pressure distribution on
buildings and calculation of natural-ventilation airflow”. ASHRAE
Transactions, 94, (1), pp243-266.
Tsuchiya Y, Horikoshi C and Sato T: (1983) “Study on the diffusion of the
rectangular jet”, Transactions of Japan Society of Mechanical
Engineers, Series B 49, (438), pp376-385.
Walker I., Wilson D. and Forest T: (1996) “Wind shadow model for air
infiltration sheltering by upwind obstacles. HVAC&R Research,
2, (4), pp265-283.
Wiren B: (1983) “Effects of surrounding buildings on wind pressure
distributions and ventilative heat losses for a single-family house. J.
Wind Eng. Industrial Aerodynamics, (15), pp15-26.
|
