Do mini-split AC units bring fresh air inside?

[Ninshub]

I wonder if anyone knows the correct answer here.

Where I live right now there's smoky air outside due to wildfires. I have a mini-split heating & AC system, so ductless. Does this bring fresh air from the inside in?

I see sites where the answer is Yes, and others No.

So I'm confused.

[Ninshub]

Most say no, but I saw at least one say yes. Too bad it's Sunday and I can't call the company!

I have no idea, didn't even know what that was. But from the little research I did it seems this is a combined refrigerator/heat-pump where I guess just like a normal refrigerator, or freezer, there is no airflow in or out of the storage compartment, the only flow is coolant in the pipes.

But, take that with more than a pinch of salt, I'm guessing and there might be different styles and designs, if it transfers air there would be a larger-diameter pipe than the much smaller pipe for the coolant.

[Ninshub]

I have no idea, didn't even know what that was. But from the little research I did it seems this is a combined refrigerator/heat-pump where I guess just like a normal refrigerator, or freezer, there is no airflow in or out of the storage compartment, the only flow is coolant in the pipes.

But, take that with more than a pinch of salt, I'm guessing and there might be different styles and designs, if it transfers air there would be a larger-diameter pipe than the much smaller pipe for the coolant.

This site, among others, says there's no air coming from outside. And it explains the mechanism so maybe you can take a look and let me know if it makes sense to you.
https://aircondlounge.com/do-mini-splits...m-outside/

In any event, the burn smell has entered my house because it's old and not that well-insulated, so I decided to turn the AC on and smelling the air coming through the vents I can't detect a particularly smoky smell.

This site, among others, says there's no air coming from outside. And it explains the mechanism so maybe you can take a look and let me know if it makes sense to you.
https://aircondlounge.com/do-mini-splits...m-outside/

In any event, the burn smell has entered my house because it's old and not that well-insulated, so I decided to turn the AC on and smelling the air coming through the vents I can't detect a particularly smoky smell.

I'm sorry to hear about the wildfires, it's not good that they are happening and not so easy to just move away from.


That seems like a good site with clear explanations. It looks like mostly the answer is no outside air is brought in. But it does say some designs include a duct which does transfer air. So that's a 'no' with a slight 'maybe'.

I think your sniff-test probably gives you the right answer, if it was bringing air direct from outside it would surely be much more strong-smelling than the air already in the room.