Whynter - NEX ARC-1030WN Portable Air Conditioner

Whether you get a single- or dual-hose model (and dual is much more efficient) add an insulating blanket around the hot exhaust hose to increase efficiency. That made \~2º difference in my situation, and every degree helps! BTW, I've used a single-hose Koldfront for seven years and a dual Whynter for three, and both are still going strong.

You’re not doing anything wrong..portable ACs are mold traps by design. Sitting all winter with leftover moisture = fungus party. Run it on fan mode before storage to dry it out. As for brands, try Whynter or Midea dual-hose. They’re slightly easier to clean. Or go mini split and never look back.

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.

Get a dual hose. Home Depot had a nice Whynter one on sale, for like $389 which is a dual hose which means it takes air from outside and not inside and is far far more efficient. So far, so good. It blows so cold I had to cover up. Edit: link here https://www.homedepot.com/p/Whynter-NEX-10-000-BTU-12-000-BTU-ASHRAE-Portable-Air-Conditioner-Cools-500-Sq-Ft-with-Dehumidifier-Wifi-Enabled-in-White-ARC-1030WN/318926897

Realize this thread is old. OP, any update here? I'm having the same problem and it's driving me crazy.

I’ve owned multiple portable A/C units and have never had to drain them curious why Whynter is different.

I did this while using the heat mode and it still shut off every hour because the tank was full .

So which hose did you cap the intake or the outflow ?

If you’re going portable, go LG or Whynter. Midea’s hit-or-miss like a Tinder date..looks good online, but disappoints in person.

The 12K BTU portable units work fine for even a large bedroom. I have three, all Whynter two hose. One even keeps a 600 sf finished attic with seemingly no insulation in the roof at an okay temperature on hot days. When it is over 100F out, it struggles but still the attic is tolerable if not ideal.

Any dual hose one will be more efficient and possibly more quiet. I have the Whynter Arc. It does a great job. Some people may find it noisy but it doesn’t bother me. But it IS large so not easy to lug between places.

Whynter. They’re also packed very well in the box.