Portable Air Conditioner Exhaust Hose Gets Hot: Fixes

Portable air conditioners help us in keeping our rooms cool when we are experiencing hot days. However, sometimes they may not work as they ought to. Such as when your portable air conditioner exhaust hose gets hot, they can leave us with question about what to do next. 

portable air conditioner exhaust gets hot

Air conditioners are designed in such a way that they cool our rooms of space by extracting the heat from the air. The extracted heat it then vented away through the exhaust vent. So, it is normal for heat to pass though the exhaust. But if you notice that it is getting hotter than normal, then it is really something that you need to fix. 

Luckily in this article, we have identified possible reasons why your portable air conditioner exhaust is getting so how and how to fix this.  

Some of the reasons why your unit’s exhaust is getting really hot include. 

  •  Improperly vented exhaust 
  • Unsuitable air conditioner size 
  • Uninsulated exhaust 
  •  Buildup of frost in the unit 
  • Dirty air filters 

So, now let us dive into the details of each of the above possible issues and how to fix them. 

Top Reasons Why Your Portable Air Conditioner Exhaust Hose Gets Hot 

Improperly vented Exhaust

As I briefly mentioned at the beginning of this article, an air conditioner needs to be properly vented due to their design of operation. Proper ventilation is especially important as this ensures that the heated that is extract from the air withing the room is vented outside. 

Venting is done traditionally through a window but even if there are no windows, there some venting options to consider. 

However, if your portable air conditioner is not vented correctly, it will affect the efficiency and effectiveness of you air conditioner. 

Specified metrics such as the hose diameter, host length, should be left as they are. 

Proper venting involves the use of the recommended venting kit that comes with your portable air conditioner. It also means not making modifications to your exhausts such and lengthening it or making the hose shorter. This can affect the operation of your unit sometimes making it inefficient.  

Unsuitable Air conditioner Size

 The first thing you want to do before getting a portable air conditioner is know the size of you room. This is important because it will give you an idea of the size of the air conditioner that you need measure in BTUs. 

Picking a size of the air conditioner that is not suitable, either too large or too small, will affect the performance of the unit itself. 

Air cons come with BTU ratings that can help you determine size of Portable AC that you need. There are several tools online that can help you calculate the number of BTUs needed to cool your room. 

Using an air conditioner with BTUs higher than what your room need will cause intermittent on and off cycles that will make your compressor to overwork. 

It is important that you figure out the size of your room and together with other factors such as the number of occupants of the room, room insulation and the height of ceiling. These will help you get a suitable size of a portable air conditioner 

Uninsulated Exhaust Hose

portable air conditioner exhaust gets hot
A properly insulated exhaust hose

Heat passes through the exhaust host to the outside so an exhaust that is not properly insulated or wrapped will radiate heat and the hose will get hot 

If the exhaust hose is not insulated, use a duct wrap to cover so that there is no transmission of heated between the hose and its outer surface. 

Many portable air conditioners come with exhaust hose covers can easily be installed or removed for washing. 

Buildup Of Frost In The unit 

The buildup of ice and condensation of moisture in the unit is common. What happens is that when your air conditioner is extracting heat from the air within the room, the surrounding moisture can condense and then freeze around the coils. 

When this happens, the ice will start building up on the coils. This buildup can block the coils and eventually affect the performance of your air conditioner. This is the reason you might experience your portable AC exhaust hose getting hot. You may also notice undesirable temperatures in your living space. 

Another thing that will be affected by the buildup of frost of your unit’s coils is the consumption of electricity. Your ac will become inefficient as it will try to overwork to keep your room and in turn it will use up more electricity. 

Your unit can also have frequent shutdowns or even refrigerant leaks. 

The refrigerant is important in air conditioning as it absorbs the heat that is within the air in your room and thereby bringing about the cooling that you need.  

The coils are delicate and any damage to them can cause this refrigerant to leak. Without the refrigerant, an air conditioner cannot bring about any cooling no matter how long they can run. 

Dirty Air Filters 

Over time, dirt, dust, mold, and other unwanted substances get clogged in the AC filters. When this happens, your portable AC will become ineffective. You can notice this by the noise that your unit c makes and by the exhaust hose getting hot. Clogged filter can also cause the buildup of frost.  

You can prevent this buildup of frost by ensuring that the air filters are cleaned regularly. That is, for those that are washable. But for the non-washable filters ensure that you replace them with new ones in time. 

The Evaporator and condenser coils are more effective with adequate flow of air. 

Many manufactures recommend cleaning the filters 2-3 months. With dirty filters you will likely notice that your portable air conditioner fills with water quickly

If there is mold present, a common indicator of this is a musty smell. Check the drain pan and the drain. When cleaning up always mask up.  


We have looked at both possible reasons for your portable air conditioner exhaust hose getting hot and how to fix the issues. If you have tried all the tips given above and you still experience the problem, then consider calling your local technician. If your unit is within the warranty period, try contacting the manufacturers support team. 

I hope this article has been helpful.