I have an older compressor (10yrs) and one just under a year. The noise seems to be the give away what I am doing. CPAP unts are so quiet and frankly more acceptable in every environment. It has a filter with small enough pores to keep unwanted viruses and bacteria out. With the correct medical coding, you can get a unit that is free or little cost. Adapting the CPAP unit for me was a direct fit. It is also typically programmable to idealize the airflow including some things that I love like air temperature, humidifier an airflow rate. If somebody is affected by certain nebulized meds, add an Environcare or as good but lower cost activated charcoal (A-C) equipped filter unit. I will look into a simple A-C origami gizmo for office or on the go. I have made half a dozen A-C devices, it isn't rocket science and it is effective.