An article in TechInsider on 9 September reported that a Dutch designer, Daan Roosegaarde created a 23-foot tall air purifier, called the Smog Free Tower. With €113,153 raised on Kickstarter, he built a prototype in Rotterdam.
According to Roosegaarde, the Smog Free Tower supposedly works like this: a radial ventilation (his term, whatever that means) system that is powered by wind draws dirty air in at the top of the tower. The air then enters a chamber. Inside the chamber, an electrode that has a positive current running through it, sends out positive ions into the air. These positive ions attach themselves to fine dust particles smaller than 15 micrometers. This gives them a positive charge. A negatively charged surface, called the counter electrode, then draws the positive ions together with the fine dust particles, which are harmful to us if we breath them in. Clean air is then expelled through vents at the bottom of the tower, surrounding the space around the tower in a “bubble of clean air” (never mind that smoggy and hazy air will still flow into that space…). The dust particles are then stored inside the tower and can be condensed into tiny “gemstones” that can be embedded into jewelry pieces. Apparently, the whole process is powered by “green” energy.
I think the whole idea sucks. Why?
Firstly, I doubt this system can clean air fast enough to make any significant impact.
According to Roosegaarde, it can clean 30,000 cubic meters of air per hour. From data provided by the Association of Home Appliances Manufacturers (AHAM) in USA, it would require a machine that can deliver clean air at a rate of about 1000 cubic metres an hour to ensure that the air in a space the size equivalent to a four-room flat stays relatively clean. And this room has to be in a sealed condition, i.e. the doors and windows need to be closed. So the Smog Free Tower can at most deliver clean air to ensure that the air in a space with the volume of about 30 four-room flats remain relatively clean if that volume of space was sealed.
However, in reality, the space where this Smog Free Tower is deployed will probably not sealed. The rate of smoggy (or hazy, in our case) air flowing into the space would probably be far higher than the rate at which this tower can clean the air. In other words, all that effort would make a negligible dent to the PSI.
Secondly, the amount of energy used for that negligible effect is definitely not worth it.
According to Roosegaarde, the tower uses 1,400 watts of power. This means that in a hour, it uses 1.4kWh. To put that into perspective, the average one-room flat in Singapore consumes about 4kWh of energy a day. In other words, to make a negligible impact on the air quality, the tower will need to use four times the amount of energy that a typical one-room HDB flat uses in a single day. Is that worth it?
Oh but wait. The energy the tower uses is “green”! How is it green? It does not say. For instance, Roosegaard assumes that there is sufficient wind in the right direction to provide that “radial ventilation” for the tower. What if there isn’t? If there isn’t, then either the energy use is going to increase to draw the air in, or the clean air delivery rate is going to drop, i.e. efficiency of the whole system suffers and even more energy is wasted. Could the tower be powered by solar energy? Er… if it’s hazy or smoggy, there won’t be much solar energy to be collected by the panels, right?
In any case, it does not matter the source of energy. Wasted energy is wasted energy. The green energy could have been better used doing something else. Such as? Well, such as purifying the air in a sealed room when there is actually a user in it. Such a targeted approach would be more effective and efficient. It is like only having the lights on when there is a need for the lights to be on, rather than wasting energy by simply blasting light into the sky.
Put together, sexy and attractive as this Smog Free Tower may seem, I am of the opinion that it is a waste of energy because it uses too much energy to make a negligible improvement in air quality. And I am against such profligacy.
Yes, I know I should not just criticize. I should also give suggestions.
Instead of cleaning up volumes of hazy or smoggy air in open spaces, foisting the costs of doing so on to the general public, I think that the polluters – the factories and car owners should bear the costs. They should either invest in technology and production methods to cut down on harmful emissions (and no cheating!) or to have devices to clean the exhaust at point of emission.
As for the haze situation that Singapore, Malaysia and Indonesia is suffering from now, those most responsible for the situation should be heavily punished. They should be made to pay fines that are sufficiently huge that would hurt the bottom line and shareholder interests. Better yet, make the high-ranking executives in those companies serve prison sentences.
Also, the products they make should be made known and we should boycott those products. For example, there is evidence to show that the company, Asian Pulp and Paper (APP) is a company that, through its suppliers, is partially responsible for the forest burning that caused the haze. APP makes products such Paseo tissue papers and Enlivo notebooks. We should boycott these products to put additional pressure on the company to stop the practices that lead to the haze.
In conclusion, this tower is a terrible idea. Rather than be tempted by such sexy sounding but essentially wasteful ideas, we need to think of ways to reduce the pollution in the first place and internalize the negative externality by making the polluters pay.