Mini-splits don't short cycle. They run at the speed required to keep the temp where you want it. If it was 3k over, it would just run slower. You can't hear them anyway. Get somebody who has done a lot of Mini-splits. I found many here in FL that didn't know what they were talking about.I wasn't clear. He did not say oversizing it by 3000 would make it short cycle. He did say if it's oversized it will short cycle and won't dehumidify properly. He did think 18-24 was way too much and says he has several 9Kbtu units in similar spaces that work great.