I’ve always wondered how effective air conditioning is vs air purifier. So I did a simple experiment at home, see below for the results!

I’m not revealing the purifier brand to avoid discussions on brands.

EDITED: Added a test where I off both aircon and purifier after opening windows (and closing them). It went from 86 to 72 in 23 minutes. Then stagnated 69-72 for the next ten minutes.

<below results part summarized and graph made by AI>

Setup
- Master bedroom in Jurong West, near Jurong Point
- Room empty throughout
- Ceiling fan on max throughout
- Indoor PM2.5 read from the purifier's sensor

Outdoor (data.gov.sg, West)
- 5:59pm: 1-hr PM2.5 at 147, 24-hr PSI at 205
- 6:30pm: 1-hr PM2.5 at 134

Log (indoor PM2.5, µg/m³)
- 5:45 to 6:00pm, ventilator on, outside air coming in: 99 at 5:59
- 6:00 to 6:20pm, aircon on full blast: 73 at 6:12, 69 at 6:16, 66 at 6:19, 66 at 6:20
- Switched to the purifier because readings stayed at about 66 to 69 for about 5 minutes
- 6:20pm onwards, aircon off and purifier on at speed 10 with 25° oscillation: 46 at 6:23, 37 at 6:25, 31 at 6:26, 20 at 6:32, 17 at 6:38, 16 at 6:41

Summary
- Aircon phase: 99 down to 66 in 20 minutes, then it stayed at around 66 for the last 5 minutes.
- Purifier phase: 66 down to 16 in 21 minutes.

Quoted from article:

"SINGAPORE: Singapore will send preventive measure notices to seven companies in Indonesia responsible for fires causing the current haze, Minister for Sustainability and the Environment Grace Fu said on Friday (Oct 16).

The notices, which stem from Singapore’s investigations, will be issued by the National Environment Agency (NEA) under the Transboundary Haze Pollution Act, Ms Fu told a press conference.

The seven companies are: - PT Bumi Andalas Permai; - PT Bumi Mekar Hijau; - PT Paramitra Mulia Langgeng; - PT Sumatera Alam Anugerah; - PT SBA Wood Industries; - PT Hutan Lestari Raya; - PT Bangkanesia.

The notices will require each company to: deploy firefighting personnel to extinguish or prevent the spread of any fire on land it owns or occupies; stop or not start any burning activities on such land; and to submit to NEA their action plans to extinguish any fires on its land and prevent their recurrence."

With the haze getting worse, many people in Singapore are rushing to buy N95 masks. It is good that shops are setting purchase limits and promising not to raise prices. However, long queues at free mask vending machines and empty shelves show that finding masks is still a challenge.

​Are purchase limits enough to stop hoarding? How are you dealing with the bad air and mask shortages?

O-Level exam papers may be rescheduled if the 24-hour PSI forecast reaches hazardous levels, said Education Minister Desmond Lee

A-Level exams are less likely to be affected as students are older, but decisions will also depend on haze forecasts and actual ground conditions.

Mr Lee added that students who are unwell and unable to take or continue an exam should obtain a medical certificate and apply for special consideration through their schools.

To all those claiming Malaysia “doing more”. It’s the same. At least we don’t make a jackhole of noise pretending to do something.

We can try to boycott. Sure. More importantly is that we write in to our fucking MPs to demand that they make noise in parliament. Get Vivian to do some workX