I have the VIOS green Pari compressor. Pari said the compressor could not be run longer than 35 minutes to function properly. Then after it is run to let it cool down 30 minutes before running again. So, I ordered a second compressor from Direct Home Medical online (the most reasonable price -must have your Rx from doctor to provide). With two compressors I can be assured they won't burn our when I do back to back nebulizing of Levalbuterol followed by sodium chloride.