Yes, single hose portable air conditioners pull air from outside to cool the room they are operating in. These portable air conditioners work by drawing in warm air from the room through the single exhaust hose, passing it over the cooling coils, and then expelling the hot air and moisture through the same hose to the outside.
The process of pulling in warm air from the room creates negative pressure, which draws in air from the outside to replace the expelled hot air. This continuous exchange of air allows the portable air conditioner to cool the room effectively.
One potential drawback of single hose portable air conditioners is that the negative pressure can cause warm air from outside to be drawn into the room through gaps around doors and windows, reducing their overall efficiency. Additionally, since they use the same hose for both intake and exhaust, some of the cooled air is also expelled with the hot air, which can slightly decrease their cooling efficiency compared to dual hose portable air conditioners.
Dual hose portable air conditioners, on the other hand, have two separate hoses - one for intake and one for exhaust - which can offer improved cooling efficiency by not drawing in warm air from outside the room. However, single hose portable air conditioners are still widely used and can be a practical cooling solution in many situations, especially for smaller spaces or when a more permanent air conditioning system is not feasible.