portable air conditioners

[oj88]

To add to my previous post, the single-hose model will pull air from the interior to cool the condenser and then push the hot air down the hose to the outside. This design is less efficient because it pulls the already cool room air to cool the condensers. It also causes negative pressure in the room so the air it just cooled is continuously being replaced by outside air coming in through the spaces between doors and/or windows.

The dual-hose type uses one of the hoses to pull air from the outside, cool its condensers then exhaust the hot air through the second hose. This design keeps the interior air totally isolated from the outside.... no negative pressure and it is significantly more efficient at cooling, HP for HP, compared to a single-hose model.

Simple illustration: