Emergency Department (ED) overcrowding is a common medical care issue in the United States and other developed nations. One major cause of ED crowding are holding patients waiting in the Emergency Room (ER) for inpatient unit admission where they block critical ED resources. With input data from a hospital in Massachusetts/USA, we tested five patient buffer concepts which aim at relieving pressure of the ER. The buffers are also assumed to improve patient and staff satisfaction through their design tailored to needs in patient flow. To ensure patients safety, we performed tests with discrete event simulation in which we discovered `triage to bed time' reductions of up to 22% and `diversion hour' decreases of up to 24%. All buffers managed to run with significantly less resources than the ER. Our findings have a potential impact on hospital process flow due to clear results which offer substantial improvement of hospital organization.