I Love Snowstorms
No. Singapore too humid. You need to get an air conditioner.

louscannon
Even in the UK, where humidity is not usually significant - air coolers are little more than glorified fans. The unit I had (abot £50) did little more than move the air about, even though I had freezer packs in the water reservoir. Plus it swiftly developed an unpleasant smell due to the standing water... Late last Summer I got a mono aircon unit from Asda (£130), about the size of a large rucksack, which does provide a cooled (and dried) airflow. It has a vent like a tumble drier (but the hose has to be more substantial - it gets very hot) which has to be directed outside... so a window has to be left open! I intend to plumb it into the wall so that it has it's own vent - one day... It is very noisy. I don't put it on after 21:00 for fear of disturbing the children/neighbours. It's next to the desk I work at, and it's like sitting next to a fast spin washing machine with a couple of vacuum cleaners on top... From my experience of living in Hong Kong, which was usually cooler and less humid than Singapore, I suspect that a dual aircon unit would be the norm - this separates the noisy part (compressor) from the part delivering the cold dry air. This will need to be plumbed in with fixed piping (compressor outside), and as the unit is likely to be on more often than it's off, quality would be paramount, and regular maintenance recommended. Effective operation of a dual unit actually requires that doors and windows be closed, so that should suit! So, short answer: air coolers don't even work well in the UK's climate, so they would be worthless where hot and humid is the norm. A waste of money!