Does a portable AC need to go outside?

We’ve all had days when we wish we could just air condition the outside as well as the inside. Maybe you’re planning a party and want a way to keep everyone cool while enjoying the summer sun. 

Well, portable air conditioners don’t work well outside unless you’re using them in a tent or some other enclosed space. 

Does portable AC need to go outside?

No, portable AC does not need to go outside. Other air conditioners have external units that get rid of excess heat but a portable air conditioner connects to an open window via an exhaust tube to get rid of heat. 

The best way to think about how a portable air conditioner works is that it removes heat from your home. There’s no way to produce cold because cold is just the absence of thermal energy. 

Your portable air conditioner needs to get rid of all that excess heat once it’s been removed from your indoor air. Otherwise, your room would stay at the same temperature. 

Here’s a bit more insight into how this process works. Your portable air conditioner has two sections. One section contains all the cooling components and the other contains heating components.

A chemical called refrigerant moves between the two through a system of pipes. When it’s on the hot side a motor inside your portable AC squeezes it to increase its temperature. The motor isn’t heating the refrigerant up. 

Rather, it is packing the same amount of thermal energy into a smaller space by making the refrigerant denser. The result is that the refrigerant gets hotter than room temperature and starts to heat up the air the portable AC will then blow out the exhaust tube.

On the other side, an expansion valve limits the amount of refrigerant that can pass into the cold side. This spreads thermal energy over a wider area as the refrigerant is less dense, making it colder than room temperature. 

Colder refrigerant is then able to suck heat (thermal energy) out of the air in your home. 

It doesn’t really matter if you got all that. The most important thing to remember is that you need to vent the hot air from your portable air conditioner somehow.

A traditional air conditioning unit does this with a separate external unit that goes outside. For example, a split AC will have an indoor unit that is connected to an external unit in your garden or attached to the side of the building. This external unit does the same job as the hot half of your portable air conditioner.

Provided you connect an exhaust tube to your portable air conditioner, then you don’t need an outdoor unit.

Can you use portable AC outside?

You can use a portable AC outside but only if you plan on cooling an enclosed space like a tent or shed. 

If you paid attention to the previous section in this article, you’ll know that portable air conditioners produce both hot and cold air. So you need to cool down an enclosed space and send the hot air outside of that space. 

Otherwise, you’d just be sitting in the middle of a stream of both hot and cold air canceling each other out.

Also, you’re never going to win the battle against the entire outdoor space. All the cold air will just float away and at best you’ll cold down the area immediately in front of you.

A better solution is to use a fan or even an evaporative cooler to beat the heat during outdoor gatherings. You’ll be just as cool provided you sit immediately in front of the fan and you won’t burn through a ton of energy producing cold air that will just get blown away.

Using a portable air conditioner in a tent is certainly possible but you’ll need access to a power source and enough space in your tent to store the portable air conditioner. Stick the exhaust tube through an opening in the tent and do your best to maintain that seal. 

One of the downsides of using a portable air conditioner in a tent is that tents are very poorly insulated. That means you’ll need to run your portable air conditioner more or less continuously to make up for the cold air you’re losing through the tent’s walls.

Also, don’t forget that portable air conditioners can be very heavy. Most units are 50 – 80 pounds. It might be worth it to you to drive a portable air conditioner to wherever you’re camping but don’t be under the illusion that you’re going to carry it on your back. 

Other ways to vent portable AC?

An exhaust tube is just one of several options for venting a portable AC. Here are some other options to get rid of the heat produced by your portable air conditioner:

• Ceiling vent: This option only works well if you have those industrial-style ceiling tiles. These types of ceilings have a space between the true ceiling and the styrofoam tiles. You can buy a ceiling vent kit that will allow you to attach the exhaust tube of your portable air conditioner in place of one of those tiles. 
• Dryer vent: Another alternative is to use an existing dryer vent. You can probably find one of these near the floor in your laundry room. Dryer vents are a good dimension to attach an exhaust tube. The only problem is that you probably don’t want to cool down the laundry room in your apartment, so the location is inconvenient. 
• Sliding door vent: You can also vent your portable AC via a sliding door vent. Normally portable air conditioners attach at the window but you can buy a door kit to fix the exhaust tube to an open sliding door. The issue is that if you block the sliding door in this way you won’t be able to use it. 
• Create a through-wall vent: Unfortunately, this approach requires a bit of DIY. Or, you could hire a professional to create a hole in an exterior wall in your home. Basically, you create a wall vent specifically for your portable air conditioner. This approach could be a good solution if you plan to use your portable air conditioner long-term. It gives you pretty good control over where your portable air conditioner will go.