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If you are concerned that you’ve an AC unit blowing hot air outside, then you are going to find this article useful. If your ac unit is blowing hot air outside when your ac is running properly and cooling your home inside, be rest assured that, this is completely normal, and your AC is working just fine.
Otherwise, you should only be concerned if your ac outside unit is blowing cold air or no air at all. Shortly I’ll be explaining how your ac system is designed to work in order to get rid of and dispose heat from your home.
Why Is My AC Unit Blowing Hot Air Outside?
If your ac outside unit is blowing hot air, you don’t need to worry about it at all. You should actually be happy because it’s a sign that your air conditioner is working as it should.
However, if your system is a heat pump and is blowing hot air outside when you have set it to heat, your home, that’s when you should be concerned. So, let’s look at why your air conditioner should be blowing hot air outside when its running. But first, we need to briefly understand how an air conditioning system works.
How Does an Air Conditioner Work?
An Air conditioner works by transferring heat from your home and disposing it to the outside air. It’s worth noting that, an air conditioner does not produce air. The following are the processes involved when your air conditioner is cooling your home.
- Your ac system uses a special chemical called refrigerant as the medium to transfer heat between your indoor environment and the outdoor air.
- When you turn on your ac, the compressor will pressurize the refrigerant and raise its temperature. Then it sends it to the condenser.
- At the condenser this refrigerant in gaseous form turns into liquid and travels to the evaporator coil, found inside your home.
- It’s at the evaporator coil, that the refrigerant in liquid form will absorb heat from the air on the surface of the evaporator coil.
- This is made possible by an indoor fan that blows air around the evaporator coil. The refrigerant absorbs heat from this air which then becomes colder. Its then blown and circulates back into your home
So Then, Why Should My Outside AC Unit Blow Hot Air?
- The process of absorbing heat continues and as it takes place, the liquid refrigerant evaporates, turning in to gas.
- Then it goes to the compressor where the compressor pressurizes it and raises its temperature. From there, it’s sent to the condenser coil. At the condenser coil, the heat from the refrigerant is released to the outdoor air.
The condenser fan helps with the process of releasing heat from the refrigerant. This is achieved when the blower fan draws in air into the condenser unit from the sides and ejects it up.
As the drawn in air passes around the condenser coil, it takes away with it the heat. And that is the reason why your air conditioner unit blows hot air outside when its running.
This process continues until the temperature that you want in your home is reached.
What Does It Mean When My Air Conditioner Is Blowing Cold Air Outside?
When your air conditioner is blowing cold air outside, it could be any of the following reasons.
1) Your Air Conditioner is Set to Heat Your Home.
When you put your air conditioner or mini split heat pump on heat mode, it will work in reverse. Instead of blowing cold air inside and hot air outside, it will blow hot air inside and cold air outside.
2) Delay Mode
If you expect your air conditioner to cool your home and you notice that its blowing cool air outside, this could be because your system is in delay mode.
3) Issues With Your AC System
An ac system that is running but blowing cool air outside could also be a sign of an issue with your air conditioning system. These issues might include:
A compressor that is not working.
If your compressor is not working, no refrigerant will be sent to the condenser coil to dispose the heat. And as such, the condenser fan will blow cool air instead of hot.
And your indoor unit will not blow cold air but just air of the room temperature. A compressor can be expensive to replace that’s why many homeowners may opt to replace the whole unit.
Problems with the changeover valve
A Changeover valve is a device that helps to switch your heat pump between the heating and the cooling functionality.
If the changeover valve is stuck in the heating mode, your ac won’t cool your home on cool mode. When this is happening, your ac outside unit will blow cool air. This problem can be solved by replacing your changeover valve.
How Can I Make My Air Conditioner Work Better?
You can make your air conditioner work even better by replacing air filters and having an HVAC tune up at least twice in a year. In the spring and in the fall.
Change Air Filters on Time
Air filters are very important in the working of your HVAC system. They screen out dirt and other things you don’t want to go in your air conditioner. If they are dirty, they could also be reason for your air conditioner blowing hot air inside and cold air outside.
Its best to change filters at least twice in two months. It’s even better to change them more often if your surrounding air is dusty or if you have pets at home.
Stick to Maintenance (tunes up)
If you are to keep your HVAC system better, you need to stick to regular HVAC tune ups. HVAC tune ups are effective if done twice a year. During a tune up, a technician will typically inspect electrical components and wires to ensure they are in good shape.
He will also verify the refrigerant charge and do many more other checks. In short, maintenance tune ups, will ensure that your system is working efficiently.
Now that you have learnt why you have an ac unit blowing hot air outside. Its also important to ensure that you have regular maintenance of your cooling system. Regular maintenance will keep your cooling system working in great condition and can prolong its life. Thanks for reading
HVAC tech with over 30 years of experience. Retired and doing repair work on the side around Madison County, AL.