![]() |
| Modern-day courtyard house Copyright@ Richard Barnes |
![]() |
| Traditional Courtyard Home |
- Sufficient open spaces for light and ventilation
- Maintains a pleasant interior atmosphere throughout the year.
- Energy-efficient as it reduces the dependency on ACs and other light requirements.
- Provides spaces for cultural gathering and events.
- Best suited for larger families.
- Requires a large land area.
- Challenges affordability.
- Construction costs can be higher.
1. Thermal Performance
2. Shape of Building
Aspect Ratio (AR) is defined as “the degree of openness to the sky”. Therefore, the greater the aspect ratio, the more exposed the courtyard is to the sky. This factor is considered for the daylight and is calculated as.
Aspect ratio = area of the courtyard floor/(average height of the surrounding walls)^2
If the courtyard is wide and shallow (high aspect ratio), it performs as the sun collector. On the other hand, the narrow and deep courtyard (low aspect ratio) performs as a sun protector, in which orientation has a weak effect on the house.
4. Surface Area to Volume Ratio
Surface Area to Volume Ratio is an indication of the rate at which the building heats up during the day and cools down at night. This ratio is obtained by dividing the total surface of the building including facades and roofs by their volume.
Surface Area to Volume Ratio= Total Surface Area of Building/Volume of Building
In the summer, a higher proportion results in greater heat gain and in winter heat loss. A high ratio also provides a significant raise in the ventilation potential and daylight, which could counter the enormous surface area drawback.
5. Solar Access and Shading
The solar performance of the courtyard depends upon solar access and shading achieved in the courtyard. A shady courtyard in winter may turn up to an open courtyard in summer due to a change in the altitude angle of the sun.
6. The Solar Shadow Index
The Solar Shadow Index (SSI) is a factor that deals with winter sun exposure. The greater the solar shadow index, the deeper the wall formed by the courtyard, and thus the less winter sun reaches the floor or the south wall.
Solar Shadow Index = (South wall height)/(North-South floor width)
7. Natural Ventilation
The ventilation and air movement through the courtyard is determined by prevailing wind direction, average wind velocity, and position and size of fenestrations.
In this enclosed space, air circulation depends mainly on the ratios of the walls and window placement in the rooms in the proximity. The appropriate ratio of the courtyard building offers a cool airflow inside the house it helps in create Comfortable living and sleeping conditions during the day throughout the night. Courtyard temperature, daylight, and air can be monitored in the rooms surrounding it movement. Orientation, profundity, and height are all In order to maintain the same values.
The airflow and natural lighting can be achieved in two ways which affect the thermal comfort of the residents.
- Temperature-generated pressure differences (stack effect)
Based on the fact that hot air rises and exits through the top opening, and cool air replaces it. Stack effect phenomena are caused by the pressure difference between the outer air and the air inside structure induced through temperature variation.
- Wind-generated pressure differences (cross ventilation)
where air travels from the openings across space. During the day, the courtyard heats up quickly, which enhances the stack effect due to high air temperature differences. However, this happens when the outside temperature is cooler than inside.
8. Thermal Mass
Thermal mass is a concept in building design that describes how the mass of the building provides "inertia" against temperature fluctuations, sometimes known as the thermal flywheel effect. When outside temperatures are fluctuating throughout the day, a large thermal mass of a house can serve to "flatten out" the daily temperature fluctuations. Thermal admittance: Thermal admittance quantifies a material's ability to absorb and release heat from space as the indoor temperature changes through a period of time. Admittance values can be a useful tool in assessing heat flows into and out of thermal storage. Admittance is measured in W/(m2K). So that
h = NQ / A x NT
Where: h = heat transfer coefficient, W/(m2K)
NQ = heat input or heat lost, W
A = heat transfer surface, m2
NT = difference in temperature between the solid surface and the
adjacent air space.
Higher admittance values indicate higher thermal mass.
·



No comments:
Post a Comment