[omnimus]

They work ok in some places where have insulated windows and some source of colder air to get in.

Since these one tube systems just push hot air out, you are creating low pressure in your room and you will suck the air in from somewhere. Often times simply from outside from the leaky windows.

I don't understand why it's hard to buy systems with two hoses that would keep the pressure in the room.

[fc417fc802]

Insulated windows? That would apply equally to any other system. Where care is required is sealing around whatever passes through the window.

As to the negative pressure, personally I just leave the door to the room cracked open very slightly. But if you have central heat ducts air will get sucked in through that no problem.

[omnimus]

What i mean is that if you don’t have somewhere to take the colder air to take from you just end up sucking hot air in.

In system where the pressure would be equalized the leaks would be much smaller. For some reason it's impossible to buy these type units in EU.