The purpose of this pilot study is to evaluate the effect of high intensity non-invasive positive pressure ventilation (HINPPV) for stable, hypercapnic COPD patients. The investigators believe that HINPPV, used at least 6 hours nocturnally over three months, will benefit the stable hypercapnic COPD patient through a reduction in the daytime partial pressure of carbon dioxide in arterial blood (PaCO2) levels.