how to make portable air conditioner more efficient

How to make a Portable Air Conditioner more efficient?

How to make a portable air conditioner more efficient? Portable air conditioners can turn into a money drain if you don’t use them properly.

This article is all about helping you to make sure that you are running your portable air conditioner at the highest efficiency.

After reading this, you’ll know exactly what to do in order to increase the cooling power of your portable AC while maintaining low electricity usage and therefore lower cost.

Quick answer: You can make a portable air conditioner more efficient by insulating your room and the exhaust hose. Also, old portable air conditioners are inefficient. Replace your old air conditioner with a new one. Additionally, run your portable AC at moderate settings since that’s where the efficiency is highest.

Let’s have a look at all these steps in a little more detail.

Improve the air conditioning efficiency in your environment

You can make the by far greatest impact on your portable air conditioner efficiency without even touching the air conditioner itself.

An air conditioner essentially extracts heat from your room and blows it outdoors. You use the air conditioner to cool down your room. But cooling a room becomes a really tedious (and inefficient) job for your portable air conditioner if heat enters the room through other ways.

That’s why you should always make sure that your room is well-insulated.

You can achieve the best insulation by having very thick walls.

The advantage of good insulation is that it is always just a one-off cost. And it will last a lifetime.

Have you ever been to an old European castle with really thick walls? It’s always cool inside. Even without air conditioning.

The obvious disadvantage of good insulation is that it is potentially pricey. Also, you need to put in lots of work to renovate. If you can’t do it yourself, you have to hire an expert to do it for you.

Luckily, you don’t have to refurbish your home in order to insulate your home well! Yes, good insulation helps a lot. But if this is out of your range of possibilities, even slight adjustments in your environment can have a significant impact on your portable air conditioner’s efficiency.

You can insulate your room in lots of different ways. Good insulation can be thick walls, walls with additional insulation, or insulated ceiling.

Every measure you take that prevents heat exchange with other rooms or outdoors helps.

Simple insulation tips to improve air conditioning efficiency

You likely don’t want to thicken your walls or add an extra insulation layer to your ceiling. If you can, then go ahead and do it!

This section is about a few simple things you can do that significantly help your AC’s efficiency.

Always keep the door closed

You should always close the door to your room. With a closed door, your portable AC only has to cool one room at a time. With an open door, you would instead be cooling your entire apartment.

By closing the door you restrict the amount of air your portable air conditioner has to cool to only your room’s size.

Block airways below your door

Also, you always want to prevent hot air from leaking into your room. Therefore you should make sure that the airways below your door are blocked.

You can use a bathroom towel or a rolled-up thin blanket and place it below your door.

Don’t worry about oxygen. This does not cut you off fresh air. It only cuts off heat.

You can vent your room anytime.

Install windows that insulate well

Heat can enter your room in two different ways. One is the movement of warm air into your room. By reducing the open airways into your room you can ensure that the least amount of hot air enters your room.

The other way that heat can enter your room is through-wall heat exchange.

Heat does not have to be carried by a stream of air to get into your room. It can also penetrate your walls or your windows. 

To have a well-insulated room, good multi-layered glass windows are essential. The most common modern windows consist of 3 thin layers of glass.

Each gap between these glass layers traps a layer of air. The air acts as an insulator.

If you have 2 layers or even 1 layer windows, then I would suggest you upgrade them.

Heat insulating windows help you not only in summer to maintain the portable air conditioner temperature but also in winter when you want to keep heat inside.

Replace your old air conditioner with a new and efficient one

Old portable air conditioners are often not as efficient as new ones. One reason is that the compressor (which constantly moves up and down) wears down over time and cannot move as smoothly as when it was new.

Aside from decreasing the cooling efficiency because parts don’t move as smoothly anymore, the increased internal friction and imbalance also cause your old portable air conditioner to be noisy.

Additionally, new portable air conditioners usually come equipped with the newest technologies and are sure to have higher energy efficiency.

Whenever I look for major electric appliances to buy, such as dishwashers, washing machines, etc. I find that even 5 years difference to the model I have at home makes a big difference in energy efficiency.

Of course, this does not mean you should buy a new portable AC every few years. This would not be worth it since the initial cost of buying is relatively high.

But I would estimate that buying a new portable air conditioner for the sake of lowering your electricity bill, reducing noise and better efficiency is worth it every 5-8 years. 

Insulate your air conditioner hose

Another thing that will significantly improve your portable air conditioner efficiency is to insulate the air conditioner’s exhaust hose.

Keep in mind the goal of your portable air conditioner is to cool your room. To cool your room, the AC extracts the heat energy from the air and blows the heat outdoors.

This means that the exhaust hose always contains hot air and therefore acts as a heating body inside your room. It is similar to having a small space heater on running while you actually want to cool your room.

The problem gets even worse if your air conditioner hose has leaks that allow the hot air to reenter your room. This would nullify the point of having a portable air conditioner running in the first place.

Additionally, the portable air conditioner fan, which pushes the hot air outdoors would have to blow harder in order to get the same amount of hot air outdoors as without leaks. This decreases efficiency.

Therefore it is also crucial that parts that are connected to your AC’s hose such as the window insert and the hose connector have no gaps. The hose connections should be tight and bullet-proof.

For some people, the portable air conditioner hose sits loosely. I wrote an article on how to prevent the portable air conditioner hose from falling out here.

Use HVAC tape to seal leaks

To insulate your portable air conditioner hose you can wrap aluminum foil around it, which prevents the heat radiation from exiting the hose.

As an engineer, I am not really sure how much of a difference aluminum foil makes. It can help for sure. But the most important point is to ensure that there are no apparent leaks in your hose.

If there are any leaks, you can fix them with temperature-resistant HVAC tape (click here to view it on amazon). That’s a special kind of duct tape that can withstand higher temperatures without the glue melting.

It’s specially made for air conditioner use-cases.

Regular tape might help as well but it is for sure not as durable and sticky as HVAC tape.

Additionally HVAC tape insulates and prevents any leakage of heat. If you want you can wrap the entire hose in HVAC tape.

Lower your air conditioner’s settings

While portable air conditioners make your life comfortable by allowing you to portably cool your room, they can come with tradeoffs. Usually, a tradeoff is that they are not as powerful and efficient as fixed non-portable air conditioners.

One reason is that the exhaust hose of a portable air conditioner is much longer than that of a regular AC. The exhaust hose returns some heat to the room which we don’t want.

Also, lots of portable ACs come with only one hose. Actually, an AC needs two separate airways. One to suck in air from outdoors and one to blow hot air from your room out.

Portable ACs that have only one hose have to suck in the cool air from indoors and blow it out. This is fatal to efficiency. But it helps with convenience.

That’s why most portable air conditioners can’t compete with fixed ACs when it comes to efficiency.

To not suck in too much cold air from your room and blow it outdoors, usually, it is better to run your portable AC on lower settings. With lower settings, I mean that you don’t cool as much and the fan is set to a moderate level.

Don’t worry. Even on moderate settings, a portable air conditioner will get you through the high summer heat. As long as you don’t expect arctic cold you should be able to efficiently cool your room on moderate settings.


The best way to make your portable air conditioner more efficient is to ensure that the exhaust hose is tightly connected and has no leaks.

Also, if you have an old portable AC, buying a newer model might be worth considering. Not only are newer models oftentimes more efficient, but you also get rid of noise and possibly the smell of your old AC.

Also, portable air conditioners run more efficiently on moderate settings. Don’t turn your room into a fridge.

Since portable air conditioners oftentimes only have one hose they are not suited to cool your room to really low temperatures.

About the Author

Daniel Hirsch

Daniel is an electrical engineer, blogger, and author. He studied electrical engineering and information technology and decided to blog about heaters after working in the temperature sensing industry.