I am not allowed to have a window air conditioner where I live so I searched high and low for a solution that was a compromise. I considered dual hose units as a priority but I realized unit noise level and inconspicuancy was more important. This fit the bill. I was able to install and use  it without it being noticed. It successfully cooled a 300 sq ft area within a short time from 85 to 75 degrees. I made sure to cover vents and cracks beforehand. 
It was a lifesaver during the hottest part of the summer and appears to be energy efficient as well. 
Expensive unit but pleased with my purchase so far.