Beating the Haze!
By now, the world has once again heard about Singapore & mistaken us as some China state. Hint to these people, Google ASEAN or South-East Asia. Some people are still hazy about who we are (pun intended.)
But I digress. There are many ways for people to beat the haze but the best is to stay indoors with the air-con on and all doors & windows closed as tightly as possible. If you have put off installing an air-con in the house, please consider doing so now, as the haze will be with us for many more weeks. Look at my post here on how to choose an air-con suitable to your house in Singapore.
Offices are usually the best as the air-cons are maintained by professionals regularly. The air-cons at home, may not be maintained as regularly so do clean them today if you haven’t done so in the last 3 months. I just cleaned mine today & there’re a lot of grey ash on it.
Many people are also turning to air purifiers to help clean the air in their home or office and while many of the good ones are effective, they also tend to be noisy ( >60dB on high setting), not to mention they cost many thousands of dollars.
Let’s take a look at some that I’ve come across.
Air purifiers work by pushing & pulling air through multiple membrane filters. Due to the resistive nature of membrane, the fan motor must be very powerful in order to move enough air to be effective. Hence, you have 2 types of noise, mechanical noise from the motor & wind noise. The situation is worst in air purifiers with HEPA filters because those are so restrictive to air flow, hence some makers like Rainbow & Delphin use water as the main filter + a “L-Lamella” separator cone to reject fine dust.
Rainbow still include a HEPA filter but this results in the motor having to work very hard & it’s really loud when vacuuming. When purifying air, it’s not as annoying but still noisy. The air flow also doesn’t seem as high as the Delphin.
The advantage of water-based system are they’re less restrictive to air flow and thus saves energy + can recycle the air faster. Even if they can’t filter the same amount of dust in 1 cycle, the amount of air they can process in the same amount of time makes up for their lower efficiency. This is especially true for the Delphin system which doesn’t have any membrane filter at all!
Water is also able to dissolve much of the harmful chemicals & odour in the air that membrane filters are not able to remove. This is why many air-purifiers also include a charcoal (or activated carbon) filter which adds to the cost of purchase and maintenance.
OK fine, I just want to know the cheapest & fastest way to purify my air!
Why I’m glad you asked. If you’ve skip the above explanation, that’s fine. I recommend using the air-con as your MAIN air purifier for 2 simple reasons. It’s the most efficient and fastest mover of air in the house, and it’s also very quiet (typically 25dB on Auto).
BUT, obviously the filters in your air-con are not actually very good. Some air-cons have UV and Plasma technology. UV kills virus & bacteria so it only sterilize the air, not filter dust.
Cold Plasma technology is basically air-ionization, which introduce an electrical charge to dust particles so they can stick to another charged surface. However, this introduce a small amount of ozone which is unhealthy with prolonged inhalation. The charged dust particle must still stick to another opposite charged surface before it’s removed from the air so its efficiency is not consistent in every environment.
SO, the best solution is to introduce another filter behind your air-con filter.
I recommend the 3M Filtrete Room Air Cleaning Filter with Carbon.
It’s an electrically-charged membrane filter with carbon so it’s able to filter particle down to 0.3 micron + the carbon will help to absorb harmful chemicals & odour. It’s not as efficient as a HEPA filter but because the air-con is pushing so much more air through the filter per minute, the result is still very good with noticeably cleaner & neutral smelling air in 10 minutes.
It’s recommended to cover up to 70% of the air-con filter to allow good air-flow so the air-con cooling power is not compromised. Don’t worry, after 1 month, the membrane will turn a icky grey to let you know the filter IS working. The filter is rated to work for 2 months but with this haze, I recommend changing it sooner, when the filter turns completely grey.
Each box contains 2 pieces of 60 x 30cm filter, which is enough to last an air-con blower unit 18 months if you change it every 2 months.
For less than $30 per air-con unit per year, I’d say that’s VERY cheap!
Lastly, for you people who are lazy, you can install the 3M filter OVER the air-con filter so you don’t even need to wash the filter in future. Obviously, the 3M filter will get dirty faster but since the haze wouldn’t last forever, it’s completely fine. 😉