WHAT is west sun exposure?
Ever wonder why is it so important to get a residential unit with minimal or no west sun exposure? Let us take a step backward to understand what is west sun exposure. As we all know, Singapore is located along the Earth’s equator. Therefore, we are the closest to the Sun from any point on Earth. This also implies that we will get the most direct sunlight from the Sun which consist of components like UV (ultra violet), IR (infra-red) and visible light. As the Sun rises from the East and gradually set in the West (due to Earth rotation along its axis), we will get the most sunlight with high level of UV of up to 5 hours from 12pm to 4pm (based on NEA recorded data on a little cloud cover day). The heat we felt from sunlight is mainly from IR rather than UV but UV will cause more harm to human and material than IR which is why we are trying to avoid the afternoon sun (a.k.a. west sun).
Does it occur to you that every time you reach home, you will reach out for the air-con controller or activate the ceiling fan to cool down the internal space. A hot house happens when the residential unit is exposed to direct sunlight, which carries UV and IR. UV and IR transmit through materials like window and wall, though the former will allow higher transmission. More building surfaces expose to direct sunlight during the peak period (12pm to 4pm) will allow more UV and IR to transmit through.
Prolong UV exposure will degrade building materials externally and internally. A simple example can be traced to the discolouration of your curtain when you compare both sides of the fabric, cracked floor tiles, cracked leather sofa, broken plastic materials, discolouration of floor tiles, etc. All these will lead to higher maintenance cost in the long run due to higher wear and tear.
Higher indoor air temperature will also translate to higher energy consumption to disperse the additional heat trapped indoors. Air conditioning will need to work extra hard; ceiling fan need to turn faster and with it more energy being consumed and more cost involved which includes maintaining and replacing the air-conditioning units. Attached chart showing the quarterly household electricity tariff from 2017 till 2019 with data from SP Service Singapore shows a visible yearly increment in terms of energy prices and this trend will continue with fluctuated raw material cost (natural gas) to generate electricity as well as accompanied sales tax.
Warm weather will persist in the long run. Attached is a graphical presentation by Straits Times with data from MSS (Meteorological Service Singapore) clearly reflect a warmer last 10 years (2009-2018) compare to all previous year on record. If the weather pattern persists or getting worse, all the above mentioned will increase exponentially. To mitigate or reduce the Urban Heat Island (UHI) effect which cause warmer weather in Singapore, a cross-institutional initiative named ‘Cooling Singapore’ have been set up to develop a roadmap to achieve this (www.coolingsingapore.sg).
"Singapore may have escaped heatwaves of this magnitude in recent times, but Dr Eeqmal stressed that the island is just getting warmer.
He said that in the last 10 years, January has been “as warm, or warmer” than what May was in the 1970s. “Our coolest month now is as warm as what our hottest month was then.” - TODAY
Difficulty to sell the property in the future. The current method selling property will change drastically when the Singapore government decided to release work done under ‘Virtual Singapore’ in the near future. Virtual Singapore (https://www.nrf.gov.sg/programmes/virtual-singapore) is a $73m initiative by NRF (National Research Foundation) to develop a dynamic 3D model of Singapore with collaborative data. Data such as how many hours of daylight exposure for every single unit will be made available for completed housing units, this will allow informed decision making by potential buyers. In short, if you buy a hot house now, you will find it hard to sell in later date as buyers will know how bad the situation will be.
Throughout the entire selection process, (hausanalyst) was readily available to answer any of our queries. (Hausanalyst) also made us realized that most of the “older generation” assumptions (i.e. west sun direction, high floor and etc) were all wrong. (Hausanalyst) report is also very detailed in a way that it included elements like unit to unit distance, unit to rubbish chute distance, the exact sun shading of the unit, and also a 3D view of the unit of your choice. All these elements are the nitty gritty details where one might disregard when it comes to selection of a unit."
Mr. Zy | engineer, SAF | Tampines Green Gem 4-rm 2018
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