Thursday 1 November 2018

Tech Report (Draft #2)

Executive Summary

Report on the solution to having cleaner indoor air using electrostatic precipitators to filter out PM2.5 particles from circulation indoors.

Background


Despite being a clean and green country, the carbon emissions in Singapore is relatively high in proportion to its size. This proposal is a response to the poor air quality that we breathe in due to the high carbon emissions.

Singapore is one of the most well-established countries in the world. We have many vehicles roaming our streets along with industrial building constantly releasing harmful particles into the air daily. A research done by the National Climate Change Secretariat of Singapore (2018) stated that “Singapore contributes to 0.11% of the global emissions”. The percentage may seem small, but considering the size of our country, it is a rather large contribution. The article further shows that Singapore ranks 123rd place in terms of CO2 per dollar GDP, ahead of countries like the United Kingdom and France which are many times larger than our country. This shows that Singapore does have an issue with air pollution.

Air is essential to every human being, however, the air that we are breathing in could be affecting our health in the long run. Such harmful particles are known as ‘particulate matter 2.5’, PM2.5. It refers to tiny particles that are 2.5 micrometers (µm) or less in diameter, often called fine PM. PM2.5 causes by men are more severe than natural sources, the particles are directly emitted into the air from motor vehicles, forest burnings, and industrial gases. As they are so small and light, they stay longer in the air causing the air to be polluted and increases the chances of people inhaling it. Due to their tiny size, the particles can enter our lungs and circulatory system. This could cause health hazards both in the short and long run. An article published on the US National Library of Medicine National Institute of Health (NCBI, 2002) stated that “Long-term exposure to combustion-related fine particulate air pollution is an important environmental risk factor for cardiopulmonary and lung cancer mortality.” Based on a guideline by the World Health Organisation (WHO, 2018), the PM2.5 levels should be at 10µgc annual mean and 25µgc for 24 hours mean. According to the psi index by The National Environment Agency (2018), the psi levels in Singapore currently falls within the range of 50μg/m3 to 60μg/m3 daily, which are beyond the levels listed by WHO.

The factors which have contributed to PM 2.5 in Singapore are mainly from vehicles and industrial factories. These PM 2.5 can also be the product formed by chemical reactions in the atmosphere. An article by The Straits Times stated that “due to the concentration of particle vapour and local emissions - from cars and factories”. These small-sized particles are not entirely from the neighbouring country that carries out deforestation which in the later part of the article stated, “experts point to culprits closer to home: factories and cars”.  

During the haze period, one of the strategies that Singaporeans use to counter haze problem is to stay indoors and use air-conditioners, as is it advisable to limit outdoor activities when the PSI level is high. While all doors and windows are closed, it can limit the particles in the haze from entering the houses. However, conventional air-conditioners are unable to filter the tiny particles like PM2.5, so there are still chances of breathing them in.

When indoors, the air condition will always be on. A building grade air conditioning uses Heating, Ventilation and Air Conditioning system, known as HVAC. The main purpose of a HVAC system is to provide thermal comfort and acceptable indoor air quality. The most common HVAC system used in buildings are called packaged rooftop units. Unlike the split system which is used in residential air conditioning units, it has everything stored in one unit, therefore the name packaged. The packaged rooftop units include an evaporator coil, fan, compressor, condenser and are situated on the roof.

Problem Statement

An ideal innovative campus should adopt an advanced approach which can circulate clean indoor air and provide a conducive environment to study without being affected by the air quality. Due to the location of the SIT@Dover, the air quality is affected by the carbon emission of cars along the highway and the industrial buildings near the coast, resulting in a build-up of air pollution around the school which would be harmful to students. Inserting electrostatic precipitators to the air cons, it will filter out PM2.5 particles from the indoor air and circulate back clean air around the room.

Purpose Statement

The purpose of this report is to propose to the facility manager of SIT@Dover to install electrostatic precipitators into the current campus and, to emphasise to the facility manager that this advance approach can provide a clean and conducive learning space for the students and staff alike.

Proposed Solution

Our proposed solution to removing PM2.5 particles from circulation is to introduce electrostatic precipitators in our air conditioning filters. Electrostatic Precipitator is a highly effective device that removes suspended dust particles that are smaller than PM 10 by applying a high-voltage electrostatic charge and collecting the particles on charged plates. Clean air would then be distributed back out for circulation.


Figure 1. PowerClean™ Electrostatic Precipitator with Automatic Cleaning

Benefits of Electrostatic Precipitator

The are many benefits that Electrostatic Precipitator provides which are: able to remove tiny dust particles which are as small as PM 0.01 and ease of operation. This shows that this precipitator is definitely a great investment which SIT@Dover can consider as the location of the school is situated beside the expressway. Thus, it is beneficial for the students as the students are able to study comfortably without any difficulties in concentrating due to the dust.  ...                                                                                                                                                 
Summary of benefits of using electrostatic precipitator filter.

Clean air

The electrostatic precipitator would be able to circulate clean air around the room by removing small dust particles from the air. It would improve the respiratory health of students and staff.

Low operating costs

With the installation of electrostatic precipitators, it has a long service life and requires little maintenance as well as low operating costs unless used at high efficiencies. This would prove to be a good investment in the long run with its low operating costs.


Evaluation

Electrostatic Precipitators have a high capital cost which is a big factor to consider before installing it on the campus. This will most likely be the biggest factor as campuses are funded by the government and may not have the budget to install these filters on a large scale. On top of that, the electrostatic precipitators are not flexible. Once installed, it is hard to move it.

However, with all this limitation in place, the advantages outweigh them all. As most HVAC systems are located on the roof, the space that an electrostatic precipitator needs is not a big issue. The installation of these precipitators will most likely be permanent which means that flexibility will not be an issue either. 

Limitations of Electrostatic Precipitator

However, nothing is perfect. There are also some disadvantages of Electrostatic Precipitators, for example, the system is difficult to change working conditions once it is installed for the air-conditioner and it is bulky.

The electrostatic precipitator can only be used to collect dry and wet pollutants. It cannot collect gaseous pollutants.

In addition, it requires a high initial cost to install, not practical for small industry or household use.

Moreover, the equipment itself is quite expensive and periodically maintenance cost is high and taking extra space.


References


Ambient (Outdoor) Air Quality and Health. (2018). Retrieved October 31, 2018, http://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health

Pope CA 3rd, Burnett RT, Thun MJ, Calle EE, Krewski D, Ito K, Thurston GD. (2002). Lung cancer, cardiopulmonary mortality, and long-term exposure to fine particulate air pollution. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/11879110

https://www.haze.gov.sg/home

PowerClean™ Electrostatic Precipitator with Automatic Cleaning [Image]. Retrieved from http://www.airscrubbersinc.com/products/kitchen-exhaust-electrostatic-powerclean.htm

Singapore’s Emissions Profile. (2018). Retrieved October 31, 2018, https://www.nccs.gov.sg/climate-change-and-singapore/national-circumstances/singapore's-emissions-profile

Aggarwal, N. (2013). Working of electrostatic precipitators with its advantages and disadvantages. Retrieved from https://www.indiastudychannel.com/resources/140937-Working-of-electrostatic-precipitators-with-its-advantages-and-disadvantages.aspx


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