Which facing is naturally cooler in Singapore?
When choosing a unit in Singapore, facing is an unavoidable topic. Who don't want a naturally cooler facing unit?
In this post, I will share with you the analysis from several aspects. You can also jump to the Conclusions and check if it is aligned with what you think. If you prefer reading it in Chinese, click here. 阅读华文版本，请点击。
Some countries have Spring, Summer, Autumn, and Winter.
But Singapore has 3 seasons
Singapore is close to the equator and has a tropical rain-forest climate. The annual temperature is between 25 and 32 degrees, with sufficient rainfall and high air humidity.
Unlike other countries with 4 seasons, Singapore has 3 seasons here - Hot! Very Hot! ! Extremely Hot! ! ! The hottest month is around May-June, and the cooler season is from December to January. Regardless of months, the highest temperature at noon every day is almost 30 Celsius degrees.
So, an important part of improving the happiness index in Singapore is to have a naturally cooler house.
No west-sun? South-North is the best?
Which facing is naturally cooler?
Many people think that as long as no west sun, all other facings are about the same. Some firmly believe south-north facing are the best among all.
Is that true? Let’s do an analysis. To be naturally cooler, it depends on 2 factors - ventilation and exposure to direct sunlight.
Factor 1 - Ventilation
The external factor affecting ventilation is wind.
Singapore has two different monsoon seasons. The northeast monsoon is blowing from December to March, which is quite humid. The southwest monsoon is blowing from June to September. It is relatively dry. Refer to the following figure for the wind direction along the year in Singapore.
- From April to October, the wind direction is from south to north during most time of the day
- And from November to March, the wind direction is blowing from north to south.
Takeaway based on Seasonal Wind Direction
Since the hottest months are around May-June, the takeaway based on the seasonal wind direction is that south facing unit should be the 1st choice.
The internal factor affecting ventilation is if the unit can form an air tunnel for the wind to flow freely. E.g., windows (or door) at both south and north.
Factor 2 - Exposure to direct sunlight
In Singapore people will try to avoid west-sun facing unit as much as possible. Some think south-north facing units will not have west-sun. Well, although it makes sense but these opinions are not showing the full picture.
I will illustrate more using the following Sun trajectory and wind direction figure.
The orientation of the sunrise and sunset changes during the year. The 3 red dotted lines from top to bottom in the figure are the running routes of the Sun in Singapore in June, March/September, and December. In a year, the sun moves in the zone contained by the red dotted line.
Take the 1st red dotted line as an example, i.e., the Sun trajectory in the hottest month June. The sun rises about 22-degree north of east at 7am, and runs to the top at noon. Then that is what we called west-sun! The sunset is at 22-degree north of west. In this case, even for a north facing unit, the slanted west-sunlight can enter the corner of the house.
The third red dotted line is the Sun trajectory in cooler December. The sun rises about 22-degree south of east at 7am, runs to the top at noon. Again west-sun starts. At last the sunset is 22-degree south of west. Therefore in Dec, even a perfect south-facing unit will still have a 22-degree west-sun in the late afternoon.
A quick recap on Exposure to Direct Sunlight
- West facing units are baked by the west-sun all year round
- Other facing units are more or less subject to west-sun at different times of the year, except east-facing unit which has morning Sunlight.
- In the hottest month June, the north-west facing unit will be exposed to the direct west-sun, probably even hotter than west-facing units.
How about Wall facing?
In addition to the orientation of the window, you should also pay attention to the direction of the wall. If one wall faces west, it will absorb the afternoon sun and turn that room into a sauna room.
You should also take surroundings into consideration. Even if a unit has the best direction facing, it will not enjoy natural wind if it is blocked by another building.
With all the analysis above, you should consider the following factors when looking for a naturally cooler unit.
- High-rise, unblocked, an air tunnel for wind to flow freely.
- South-facing is better than north-facing because of wind from south in the hottest month June.
- The facing to be naturally cooler in sequence is indicated in different color in the figure, i.e., Blue -> Yellow -> Red.
south facing & a bit towards east –> south facing -> south facing & a bit towards west -> north/north & a bit towards east -> west, west-north, east.