Trial: "As seen on TV" Instachill evaporative cooler

Evaporative cooling keeps us cool: we sweat, then heat from our body turns it into water vapour and we cool down.

Evaporative coolers use the same science. They suck in air, pass it over water-soaked pads (the water evaporates), and blow it back into the room. The air blown out is cooler than the air sucked in.

However, this cooler air is also damper than the air sucked in – that water vapour has to go somewhere. The best practice with evaporative coolers is to use them with windows and doors open, in a semi-enclosed place, or even outside.

Evaporative coolers use water (you need to keep a water tank filled up). For example, the Instachill has a 10L tank that lasts nine to 12 hours of continuous use. That means it pumps about a litre of water into your room every hour.

Evaporative coolers work well in hot, dry climates: think Western Australia, or Nevada and Arizona.

Hot and dry is good because there’s more capacity for the air to hold water vapour – which means an evaporative cooler can create a significant temperature drop. The extra humidity it creates might also be welcomed.

Damp-old New Zealand, where most of us live close to the coast, doesn’t have a hot, dry climate. In our climate, an evaporative cooler doesn’t work nearly as well, and the extra humidity it creates does nothing to make a room more comfortable. Used in a poorly ventilated space, it could raise humidity to a level where mould thrives. Many of our homes suffer from mould anyway – we don’t need anything to help it grow.

There are exceptions - inland Canterbury, Otago and Hawkes Bay can see hotter, drier conditions late on a summer afternoon. However, the bottom line is, except for a few inland areas in high summer, there’s no place for evaporative cooling in New Zealand.

You’d be correct to think I had low expectations after researching evaporative cooling and coolers. The Instachill didn’t disappoint.

I gave it the best chance I could. I’m in Wellington, which is hardly a location in need of summer cooling. However, on collecting the Instachill from my local Harvey Norman branch, my trial felt justified – the store had several evaporative cooler models on prominent display. The nylon-tied sales guy gushed to me about how good they were – even offering a nonsensical tip to pop a couple of ice cubes in the filling tray. I’m not going to get into just how nonsensical that tip is. Trust me, I understand the science.

For my trial I lucked-out with a run of very un-Wellington-like 23-24°C days. I used the Instacool in three different rooms, each time following the instructions to leave plenty of doors and windows open. I recorded room and outdoor conditions using a few temperature and humidity loggers.

Before I get to its cooling performance, I have a few observations to offer after using the Instachill:

1. It’s a big, ugly, cheap-looking white tower. It doesn’t look great in the infomercial, but the reality is worse.
2. It’s extremely noisy, even on its lowest fan setting. It’s so loud you don’t want to be in the same room. It’s annoying trying to watch TV with it running, and I wouldn’t get to sleep with it going.
3. The lowest fan setting was strong enough to blow papers from my desk with the Instachill three metres away. The high fan setting is like sitting in a wind tunnel.
4. The instructions (awkwardly translated and poorly laid out) didn’t mention an open water tank drain bung at the back – so on first filling I covered my garage floor with water.

But you don’t buy an Instachill for discrete mid-century style. You buy it to cool down in the heat of summer. Unfortunately, in my experience, it fails there too.

In my garage, the Instachill caused a slight temperature drop (0.5°C more than the outdoor drop) over two hours, but noticeably increased humidity (by 5% more than the outdoor change).

In my 8m² home office, warmed by afternoon sun, the Instachill had a negligible effect on temperature and humidity, which stayed constant over three hours (27.0°C and 61%). In this small room I set the Instachill on its lowest fan speed to keep the wind and noise bearable.

I also tried the Instachill in this room with the doors and windows closed. In two hours the temperature increased from 25.9 to 31.4°C and humidity went up from 52% to 70%. I’d created a sauna.

In my open-plan living space, I recorded a net temperature increase and no change in humidity (compared to the outside reading) over four hours. It seems the Instachill did nothing in this large space, except to make a din.

The underwhelming performance had me fearing it was broken. To check I placed one sensor near the air inlet and a second in the air blowing out into the room. My Instachill wasn’t a dud, in the sense that it wasn’t broken. It decreased air temperature from 25.3°C to 24°C and increased its humidity from 54% to 63%. So the machine was pumping out slightly cooler, considerably damper air, as designed.

If evaporative coolers aren’t the answer (and they really aren’t), what can you do to cool off this summer?

• First, open doors and windows to create a breeze. It’ll cost you nothing and being in moving air makes you feel cooler.

• If that’s not enough, add a fan to move more air. Just a regular old desk, pedestal, tower or ceiling fan will do. To truly feel the cooling effect of a fan, you need to actually feel the breeze on your skin.

• To cool a room quickly and efficiently (and remove old, stale air), put the fan next to an open window and point it outside. It’ll suck warm air out and draw in cooler fresher air to replace it.

• If things get really hot, close the windows and turn your heat pump on in cooling mode (look for a snowflake symbol). It’ll cost more than running a fan, but will chill the air.

Instachill 09EX V2 specs

Price: $369 from Harvey Norman
Air volume: 900m³/hr
Area coverage: 15m²
Dimensions: 28 x 28 x 91cm
Water tank capacity: 10L (continuous use for 9-12 hours)
Weight (without water): 6.2kg
Running cost (as tested, high fan setting): 2.5¢/hr
Three fan speeds
Remote control