You might be a renter, want to wheel your air conditioner between rooms, or just simply don't have the cash for a fixed option. A portable air conditioner can help you beat the heat, but because of their inefficiency, it might be wise to know what you're in for if you get one.
Our tests identify the best portable air conditioners for cooling, how much they cost to run, how much noise they make and more. But first you need to work out whether they're right for you, and which size suits your home.
On this page:
- How do portable air conditioners work?
- What size portable air conditioner do you need?
- How much do portable air conditioners cost to run?
- When should you buy a portable air conditioner?
- Pros and cons of portable air conditioners
- Do portable air conditioners have energy star labels?
- Portable air conditioner features to look for
- How do you use a portable air conditioner?
- How long will my portable air conditioner last?
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How do portable air conditioners work?
Portable air conditioners work basically the same way as built-in air conditioning: they suck in warm and humid air, cool and dehumidify it, then blow it back into the room. Single-duct models, with a duct connected to a window to vent heat from the room, can be very effective at cooling most of the room, but they draw the air from the room (in order to cool it) and vent some of it outside.
Venting the hot air outside through the duct results in lower air pressure in the room, so more warm air is drawn in from the rest of the house. This is why portable air conditioners are not considered particularly efficient: they face a continual struggle to cool the room. Portable units are also noisier indoors than most split-systems (which have the advantage of having the noisiest component, the compressor, situated outside).
So while they're convenient and often comparatively cheaper than split-systems, single-duct portable air conditioners are not as effective or efficient.
Despite the name, portable air conditioners are heavy (sometimes weighing over 40kg) and not always easy to manoeuvre.
When you buy a portable air conditioner, it usually includes a venting kit so you can seal the gap around the air duct to stop the cool air escaping. The unit also condenses water from the air while cooling and this is generally collected in a tank or drained away in a tube. Many models will use the water to aid cooling, which can help with overall energy efficiency and reduce the need to empty or drain the water. Dryer air feels more comfortable and enhances the cooling effect.
Portable air conditioners are often noisy on high power – they range from 57–74dB on full blast. That's louder than a normal conversation (about 65dB).
Can portable air conditioners also dehumidify?
Yes, all portable air conditioners dehumidify as well. The amount they can dehumidify depends on their design, but it can range from 22–80 litres per day. Some manufacturers are a little coy when it comes to declaring the amount portable air con units can remove per day, so in our test results we put those that declare the amount into our comparison table and "Not stated" for those that don't.
Some marketing gurus have started to make it seem as if dehumidification is a selling point (like 'portable air conditioner with dehumidification'), but the truth is that they all have it, as do full sized reverse cycle air conditioners.
What size portable air conditioner do you need?
Rather than physical size, this is based on the cooling capacity of the portable air conditioner, which is measured in kW (kilowatts). For every extra kW, you have more cooling power, but it's also going to cost you more in energy.
Unlike reverse-cycle split-system air conditioners, which give you more cooling for your kilowatt, single duct systems (portable air conditioners) are quite inefficient. However, they also don't need any hardwired installation, so your landlord doesn't need to give you permission for it.
Recommended room sizes are roughly based on the length and width of your room in square metres – this is very rough because it generally ignores height, which we average out at about 2.4m. Some portable air conditioners do give you an indicator of the room size they'll cover, but not regularly. Manufacturers seem reluctant to reliably report on this, generally because room sizes vary a lot in height, width and length.
Multiply the width and length of your room in metres and that will give you your dimensions in m2. Each kW of cooling capacity is roughly equivalent to 6m2 so as a guide, base your purchase on this requirement.
| Room size | Example | Approx. capacity | Price guide |
|---|---|---|---|
| Small (up to 15m2) | Bedroom, study, small kitchen | 2.0–2.5kW | $300–1000 |
| Medium (20–25m2) | Bedroom with ensuite, small lounge | 2.5–3.5kW | $349–1200 |
| Large (25–30m2) | Large bedroom, mid-sized lounge, large kitchen | 3.5–5.5kW | $380–1500 |
How much do portable air conditioners cost to run?
On top of the purchase price, another important consideration is how much a portable air conditioner will cost you to use it. It's why we take energy efficiency and performance into account in our portable air con reviews.
We know that generally speaking, the more kilowatts (or cooling capacity), the more your portable air conditioner is going to cost to run. To show what this looks like, the table below is based on four hours of use per day over 90 days of summer at a cost of 40c/kWh electricity.
Larger units generally cost more to run, though performance varies significantly. We've found and recommend some units with relatively lower running costs and better cooling performance. These will again vary depending on your room-size requirements.
| Size | Average running cost | Range of running costs | Average price |
|---|---|---|---|
| 1.2–3kW | $132 | $66–161 | $585 |
| 3–4kW | $192 | $173–230 | $737 |
| 4–5kW | $242 | $210–317 | $938 |
When should you buy a portable air conditioner?
Portable air conditioner prices vary wildly depending on the retailer and season. We notice that prices jump by at least 10% and sometimes up to a few hundred dollars in the first few days of heat in spring each year as retailers gear up for consumers to spend.
As a guide, the portable air conditioners we reviewed most recently ranged between $299 and $1799, but as with all appliances, a higher price tag doesn't always guarantee better performance.
Pros and cons of portable air conditioners
Pros
- Good portable air con models can provide reasonably effective cooling.
- You can use them in rental properties.
- You can move them between rooms (but many are large and heavy).
- They're cheaper than installing a split-system air conditioner.
- They're reasonably easy to store once the weather cools down.
Cons
- They can be noisy.
- They're relatively expensive to run.
- They're not the most efficient cooling system.
- Most require a window vent, so you'll need appropriate windows.
- They're heavy to move around (ranging from 13–43kg).
- Some require a water tray to be emptied.
- They need to be near a power plug.
- They need an even surface.
- They need some space around them to work well, so they'll take up floor space.
Do portable air conditioners have energy star labels?
Portable air conditioners have historically been exempt from displaying an energy star rating. From April 2020, new portable air conditioners are now required to meet Minimum Energy Performance Standards (MEPS) and display a new 'zoned' energy rating label. This shows energy efficiency according to your location, as well as other things, including how noisy it is, its kWh use each year, and its cooling capacity.
Single-duct (one-hose) portable air conditioners such as the ones we review generally have no energy stars on their labels because, by their very nature, they aren't all that energy-efficient at cooling a room down and are best for cooling or heating a person rather than a whole room. But the new labels offer some idea of how much energy they use over time, especially if you're in a humid region.
Read more about how we use MEPS data to review portable air conditioners.
New portable air conditioners entering the market must now display an energy rating label. Single-duct air conditioners have no stars as they are not energy-efficient.
Portable air conditioner features to look for
Power cord
Manufacturers don't recommend using an extension cord with your portable air conditioner. Typically, the manuals advise against it, and claim that doing so will void your warranty. Portable air cons are relatively power hungry, and your extension cord may not be able to cope, posing an overheating or fire risk. Consider the placement of the portable air conditioner in relation to the power socket. Some cords may be too short for your setup.
Remote control
These are handy in much the same way that a TV remote is handy but with the added benefit of information on room temperature. You can also usually set automatic modes and timers to make life simple. An LCD display is useful so you can see the cooling status without having to get up and look at the screen.
Operating modes
Cool, heat (for reverse-cycle models), dry (dehumidify), automatic or fan only. Automatic or 'smart' mode means the unit can be set for a target temperature and will switch to cooling mode (or heating for reverse-cycle models) as required.
On/off timers
These are useful to program the unit to turn on/off at certain times, for instance to cool the place down before you get home from work. Sleep timers can be good at night as they switch the unit off after a set period rather than running all night, and usually have automatic temperature adjustment. This adjusts the temperature to a comfortable level for sleeping, so the air conditioner doesn't work as hard (and also more quietly) while you're sleeping.
Louvres to direct airflow
Most portable air conditioners have manually adjustable louvres, though a few have only fixed louvres. Other models have automatically oscillating louvres, which enable the cool air to be directed more widely rather than just in a fixed direction.
Window kit
These come with filler panels to close the gap in an open window and direct hot air outside using an exhaust hose.
Noise
These units can be quite loud and distracting to run, especially if they're on full blast. They can compete with normal conversation, and can be distracting if you're watching TV or listening to music.
Water drainage
Portable air conditioners will have a collection tank for water. Many new models use the water to aid cooling which reduces the need to empty water from the tank.
Ease of use
If you'll be moving the portable air conditioner from room to room, look for easy to access handles and good clearance between the floor and the bottom of the unit. Smaller wheels on pile carpet can be a nuisance.
Wi-Fi
Some newer models let you control the appliance through an app or even smart speaker. These features may be useful if you need to turn the unit on or off when you aren't home, but the standard remote control that comes with most models will usually do the job.
How do you use a portable air conditioner?
Once you've chosen your portable air conditioner, have a read through the installation instructions. A majority of the portable air conditioners we review come with window kits, which generally include a duct pipe, a spacer or slider for the window through which you're exhausting the hot air, and connection equipment for the rear of the portable air conditioner to the duct and from the duct to the slider.
You'll want to install the window kit to begin with so the hot air moves from your hot room to outside. Sliders generally require a standard window that slides up and down, so check out the kit before you buy and match it to your windows.
- Place your portable air conditioner in the most favourable spot in a room, and give it some space away from the wall.
- Install your window kit to vent hot air from the room, making sure the ducting is straight.
- Plug the portable air conditioner directly into the wall (not via an extension cord).
- Some portable air conditioners store the dehumidified water in a storage container in the unit, which you'll have to empty – though many use the water for additional cooling.
- Maintain your unit by cleaning the vents, emptying water from the storage container where necessary and removing it when not needed.
- Use a ceiling or pedestal fan to redirect cool air around the room.
Check out our step-by-step guide for installing a portable air conditioner for more tips and advice.
Can you use it without an exhaust vent?
Some models allow this with the use of a narrowed duct (a flange) that you can place through an open door to the outside, but it'll have terrible efficiency unless the rest of the door opening is sealed. If it's very hot outside, all you'll be doing is letting all the cool air out straight away.
How long will my portable air conditioner last?
Many of us check the warranty of our purchases, and unfortunately most portable air conditioner manufacturers seem to have low confidence in their products as few go above a two-year warranty.
There are a few standouts in the market which reach a moderate three-year warranty (including Aldi Stirling, Chiq, Olimpia Splendid and TCL), but this could be vastly improved.
DeLonghi and Chiq go a step further and declare warranties on their motor and compressors of five and seven years respectively.
Of course, even when your portable air conditioner warranty is over, you'll still be covered by the Australian Consumer Law for a reasonable amount of time.
Stock images: Getty, unless otherwise stated.
