If you are getting ahead of summer while the weather is still cold, this is the easiest time of year to work the decision out, without a hot week forcing your hand. The short answer: a fan does not lower the temperature at all, it only makes you feel cooler by moving air across your skin. An air cooler drops the air temperature a few degrees by evaporating water, and works best in a dry room with a window open. A portable air conditioner is the only one of the three that genuinely removes heat from the room and can hold a set temperature. Which one you need depends less on your budget than on what you are actually trying to fix.
The three options, and what each one actually does
A fan moves air, it does not cool it
This is the part that surprises people. A fan does not change the temperature of a room by even a fraction of a degree. What it does is move air across your skin, which speeds up the evaporation of sweat and carries away body heat. You feel cooler; the thermometer does not move.
That makes a fan excellent when you are in the room and useless when you are not. It also means a fan does nothing for a room that is hot because the sun has been beating on it all afternoon, beyond making it feel more bearable while you sit in front of it.
What a fan is genuinely good at: low running cost, quiet operation, no installation, and moving stale air around in a stuffy bedroom. The Midea range covers a tower fan, a bladeless fan and a pedestal option for larger rooms, so the choice is mostly about the airflow pattern you want and where the fan will sit. Current pricing is listed on each product page.
An air cooler adds moisture to drop the temperature
An air cooler, sometimes called an evaporative cooler, pulls air through a wet filter or over a water tank. As the water evaporates it absorbs heat from the air, so the air leaving the unit is genuinely cooler than the air going in.
The catch is humidity. Evaporation only works if the air can take up more moisture, so an air cooler performs well in dry conditions and progressively worse as humidity rises. It also adds moisture to the room, which is the opposite of what you want in a home already prone to damp.
The practical rule for a New Zealand home: an air cooler suits a dry, well ventilated room on a hot dry day, and you should keep a window or door open so the humid air has somewhere to go. Midea air coolers come with a 4.8L tank and a 7L tank, the larger tank meaning fewer refills through a hot afternoon.
A portable air conditioner removes heat from the room
A portable air conditioner works on the same refrigeration cycle as a hi-wall heat pump. It absorbs heat from the room air, transfers it to a refrigerant, and expels it outside through an exhaust hose fitted to a window kit. Because the heat physically leaves the room, the temperature drops and stays down.
It is the only one of the three that can hold a set temperature, and the only one that also dehumidifies as a side effect of cooling. It is also the only one that needs a window for the exhaust hose, uses noticeably more power, and makes more noise, since the compressor sits inside the room rather than outside.
The Midea range runs from a 2.6kW cooling model, through a 3.5kW cooling model, to a 3.25kW cooling and 2.9kW heating model that works in winter as well. Each product page carries the full specification and the current price.
Side by side
| Fan | Air cooler | Portable air conditioner | |
|---|---|---|---|
| Lowers room temperature | No | A few degrees, in dry air | Yes, to a set point |
| Effect on humidity | None | Raises it | Lowers it |
| Needs a window | No | Best with one open | Yes, for the exhaust hose |
| Water refills | No | Yes | Occasional drainage |
| Running cost | Lowest | Low | Highest of the three |
| Noise | Lowest | Low to moderate | Highest |
| Works when you leave the room | No | Partly | Yes |
| Purchase price | Lowest | Middle | Highest |
Which one suits your situation
You want to sleep better on a warm night
Start with a fan. Air movement across the skin is most of what makes a warm bedroom bearable, and a fan is the cheapest and quietest way to get it. A tower or bladeless design suits a bedside position because the airflow is broader and less focused than a pedestal fan.
If the room is still too warm with a fan running, that is a heat problem rather than an airflow problem, and you have moved into portable air conditioner territory.
A room that bakes in afternoon sun
A fan will not fix this and an air cooler will struggle, because the issue is accumulated heat rather than still air. A portable air conditioner is the honest answer, or a fixed hi-wall unit if it is a room you use daily. Our air conditioning range covers the fixed options, and our guide to choosing a portable air conditioner goes into sizing.
A rental where you cannot install anything
A portable air conditioner is the practical choice, since the window kit fits without modification and comes out when you leave. If the window arrangement makes a hose impossible, a fan plus good ventilation is the fallback, and an air cooler is worth trying if your climate is on the dry side.
A dry inland room on a hot day
This is where an air cooler earns its place. Lower purchase price than a portable air conditioner, much lower running cost, and no exhaust hose. Keep a window open and top the tank up.
A room that is humid as well as warm
An air cooler is the wrong tool here, since it adds moisture to a room that already has too much. A portable air conditioner cools and dehumidifies at once. If the humidity is the main complaint and the temperature is secondary, a dedicated dehumidifier does that job far more efficiently, and our guide to what size dehumidifier you need covers the sizing.
You want one unit for summer and winter
A fan and an air cooler are summer-only. A reverse cycle portable air conditioner such as the 3.25kW cooling and 2.9kW heating model covers both. A fixed heat pump does the same job better and more cheaply to run, if you can install one.
Getting more out of whichever you choose
- Close the curtains before the room heats up, not after. Blocking the sun in the morning is worth more than any appliance running in the afternoon.
- Seal the exhaust window properly on a portable air conditioner. A gap around the hose lets hot air straight back in and is the most common reason one seems underpowered.
- Point a fan across the room rather than at yourself when you want general air movement, and directly at yourself when you want maximum cooling effect.
- Rinse the air cooler filter regularly. A dirty filter reduces evaporation and starts to smell.
- Clean the filters on any cooling appliance monthly through the season. Restricted airflow costs more performance than most people expect.
- Use a fan alongside an air conditioner. Circulating the cooled air lets you set a slightly higher temperature for the same comfort.
Frequently asked questions
Does a fan actually cool a room?
No. A fan moves air across your skin so you feel cooler, but it does not lower the air temperature. That is why a fan does nothing for a room you are not in.
Is an air cooler the same as an air conditioner?
No. An air cooler evaporates water to drop the air temperature a few degrees and adds humidity to the room. An air conditioner removes heat from the room entirely and reduces humidity. They are different appliances at different prices.
Do air coolers work in New Zealand?
They work best in dry conditions with a window open. In a humid room, or a home already prone to damp, an air cooler is the wrong choice and a portable air conditioner or dehumidifier suits better.
Does a portable air conditioner need a window?
Yes. It needs the exhaust hose vented outside so the heat it removes actually leaves the room. Most units include a window kit that fits a sliding or double hung window without permanent modification.
Which is cheapest to run?
A fan by a wide margin, then an air cooler, then a portable air conditioner. The trade is that only the air conditioner actually lowers the room temperature and holds it there.
Can I use a portable air conditioner in winter?
Only if it is a reverse cycle model. The 3.25kW cooling and 2.9kW heating unit in the Midea range heats as well as cools; the cooling-only models do not.
Pick the one that matches the problem. Compare the full range of fans and air coolers for airflow and evaporative cooling, or step up to a portable air conditioner when the room genuinely needs the heat taken out of it.