I have whynter portable two duct large size, it's noisy but cools well. I would never buy a single duct portable, they pull their coil cooling air from the room, so every other room gets hot air pulled in. No bueno.
If you have the money, buy a dual hose Whynter portable AC.
Otherwise - the design and construction of single hose units is such that you won’t be able to get it to not pull vacuum, even by adding a second hose to provide it with outside air. There will be leakage inside the unit itself that will prevent you from getting a perfect loop from outside to outside. But that’s still going to be much more effective than running it with the stock single hose, so it’s worth doing, and will be your best short term solution if money is tight.
Had a wynter dual hose on my sunroom last summer (250sqft, all window, no significant insulation) and it handled the space very well. It didn’t have an inverter, was only 12k BTU, so my expectation is the zafro will absolutely crush it. The inverter is also significantly more quiet, so if you use in bedroom, it may be a great option.
Marchy_is_an_artist
