- Posted On: May 30, 2022
For many urban homes, spending a summer without the help of an AC is unthinkable. Urban homes usually have a significant amount of glazed area, which leads to increased heat gain through the building envelope. This heat gain results in the interior spaces of homes heating up fast and the heat being trapped inside with no way to escape.
This phenomenon is one of the major causes of thermal discomfort for many urban home dwellers.
However, the good news is there are energy-efficient and cost-effective alternatives to ACs. To solve this issue pragmatically, simple minor addition to your house can prove to be highly beneficial to your pocket as well as to the environment.
This little enhancement can be in the form of external movable shading systems or EMSyS. EMSyS are shading devices that are installed on the windows or glazed surfaces of a building’s façade. It controls the solar heat gain into the building while also providing natural daylight indoors.
A study report by the Lawrence Berkeley National Laboratory (LBNL) in 2009, titled High Performance Building Facade Solutions Based on Field Monitored Data, shows reduction in cooling loads by up to 80-87% due to the use of external movable shading without compromising on visual comfort.
To understand this in the Indian context, BEEP conducted a study in which a real life monitoring was carried. It was observed that in naturally ventilated mode, an individual would be ~3.5°C cooler in a room equipped with EMSyS as compared to a room with only internal curtains. At the same time, in the AC mode, the room with EMSYS had ~32% less cumulative cooling demand as compared to a room with internal curtains.
EMSyS are basic devices that can be installed on the glass surface of your home’s exterior. The mechanism is simple but effective, it lets natural light into the home while reducing solar heat absorption. A major portion of the solar energy received by a tropical nation like India is in the form of ‘diffused’ radiation due to dust and clouds in the atmosphere. While fixed shade is efficient against ‘direct’ solar radiation, it is ineffective against ‘diffused’ light. EMSyS has the ability to block the sun’s rays from getting into the building at different times of the day (External movable shading systems (EMSyS) manual). These devices are simple to install and do not necessitate any additional construction work on your home thus, being cost-effective.
These exterior shading devices come in a range of different forms and sizes, and their use is decided by the type of window or glass they will be mounted on. There are many options to choose from and awnings, vertical blinds, and other low-cost EMSyS are popular and widely available in the market.
Therefore, if you are concerned about rising electricity bills and require an environmentally friendly solution, this one-time investment has the ability to be highly beneficial in the long run.
External Movable Shading Systems (EMSyS) Manual. (2021). Retrieved from beep india: https://www.beeindia.gov.in/sites/default/files/EMSYS%20Manual_Web.pdf
High Performance Building Façade Solutions, Project: CEC-500-06-041, PIER Final Project Report,E.S.
Lee, S.E. Selkowitz, and alt., LBNL, December 2009
- Tahura Fatima