Do portable air conditioners require venting?

portable air conditioner venting

Written by Craig Boyle on 14 Apr 2021

It is hot, hot, hot, and you’re melting, so you reach for the phone to contact a portable air conditioners rentals company. Before you know it, they’ve delivered a portable unit bringing you sweet and blessed relief from the oppressive heat.

Whether you hire a portable commercial air conditioner for your office or a mobile air con suited to your home, they work like fixed units – drawing in warm air, removing heat and expelling cooled air out of the front. Meanwhile, the remaining warm air and moisture are expelled from the vent.

This naturally begs the question, do portable air conditioners require venting? The short answer is yes! That’s because hot air has to go somewhere. Otherwise, it stays in the room, which defeats the point of air conditioning.

5 ways to vent a portable air conditioner

  • through a window
  • through a door
  • through a wall
  • through a drop-ceiling
  • into a chimney

How to vent a portable AC unit?

The warm air has to go somewhere, and ideally, that is outdoors. Therefore, the easiest and most convenient way to vent a portable air conditioner is through a window. However, there are some situations where venting out of a window is impossible or a room has no windows. So, what can you do? 

Vent through a door: Every room has a door. Using one to vent is the second most common option after a window. It’s important to know where the door leads because if it’s another room, the solution may not be effective. Ideally, the door should open to an outdoor space such as a balcony.

Vent through a wall: You can attach the exhaust hose to a wall vent. In this way, air can be vented outside or into another room, such as a utility room or garage.

Venting through a drop-ceiling: The cavity between a real ceiling and a drop-ceiling is ideal for venting hot air. If you’re in an upstairs room, the heat will vent out through the roof. However, in a downstairs room, the hot air will be trapped.

Other options include venting through an unused chimney or an attic if available.

What to do if venting is not possible?

When venting outside is not possible, there are other available options to keep you cool.

Portable split air conditioner

A portable split air conditioner consists of a mobile indoor unit and a portable outdoor unit with an exhaust vent. The two units are connected by a hose containing the refrigerant, condensate pipes and power cables. One disadvantage of split systems is that hose length is limited. This means you may not be able to place the indoor unit where it will give you the most benefit.

Portable evaporative cooler

An evaporative cooler uses water-soaked pads to cool the air. A fan pulls in hot air, which evaporates as it passes over the pads and blows out cooler than when it entered. Evaporative coolers are ineffective in humid environments because the air is already filled with moisture.


If you have no other options, try free-standing or desktop fans. They will provide some relief by sending a cooling breeze your way. To increase the cooling effect, mist yourself with water from a spray bottle. However, during a heatwave, fans do nothing more than blow hot air across the room.

Typically, most rooms with windows and doors should have some venting capability. But if you are unsure, it’s always best to consult with an experienced professional.

How do portable air conditioners work?

Every portable air conditioner works in the same way. A fan sucks hot and humid air from a room and into the unit. Inside the air conditioner, the hot air condenses on coils filled with a refrigerant, and the cool air is vented back into the room. 

The by-products of this process are a lot of hot air that has to be vented outside and moisture. Portable AC units also draw out moisture while cooling the air. It collects in a reservoir and can be removed manually, through a drainpipe.

Considerations for hiring a portable AC unit

When choosing a portable air conditioner for hire there are several considerations to bear in mind. The first is to ensure you have a suitably positioned electrical outlet so you can power the unit and vent it properly. Some units require only standard electrical outlets making the installation process much simpler and quicker. You may even need an extension hose if the portable air conditioner’s exhaust hose isn’t long enough.

Room size is another essential factor because it determines the air conditioner’s size and the cooling capacity you’ll need. As a general rule, a standard 4.5kW unit cools down a room up to 30-sqm.

Your machine should also be relatively quiet. In the past, portable ACs had a reputation for making a thunderous din owing to the cooling and heating components. Nowadays, with advances in technology, they are much quieter with some units delivering a maximum noise level of 64dB, which is close to having an ordinary conversation.

Where to position your portable AC unit?

You want to get the most comfort, so positioning is crucial. The device should always be placed on a hard floor, never on a desk, shelf or chair where it could fall off. The conditioner should be in an area where the natural flow of air will not work against it.  For example, if the unit is facing a door in heavy use, it will work twice as hard every time someone comes in or goes out of the room. There also needs to be a free flow of air surrounding the device. So don’t leave it behind a desk or other obstruction.

An ideal position is in the centre of a room where cool air can radiate in all directions. Under a ceiling fan is good because it can help circulate the air. However, keep in mind that the placement of the portable AC may be guided by the venting capability of the room.

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Range of cooling solutions from Precision Air Rental

Reliable Portable Cooling Solutions

Whether you’re trying to get work done, relaxing at home or entertaining friends, you want to be cool and comfortable. If you’re without air con for whatever reason, get in touch with the experts at Precision Air Rental for portable air conditioning hire. We have an extensive range of portable ACs for hire for residential, commercial and industrial properties.

For more information and to receive a free, no-obligation quote, call us now on 02 9119 5975.

Craig Boyle

Craig Boyle

Craig is the owner of Precision Air Rental and has been in the air conditioning industry for nearly 10 years. When your building is stifling hot in the middle of summer and you need help cooling it down, Craig and his team will come to the rescue!


Precision Air Rental

Precision Air Rental

Precision Air Rental offers temporary air conditioning products that cater to residential, commercial and industrial properties, and events.
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