Humidified Nasal High-flow with Oxygen (HNHF-O2) therapy has been reported to have acute beneficial effects in patients with hypoxemic respiratory failure. HNHF-O2 may be beneficial in patients with COPD and chronic impairments in gas exchange, both hypoxemia as well as hypercapnia. HNHF-O2 may decrease work of breathing, reduce dyspnea, improve airway humidification, and potentially stabilize or reduce carbon dioxide levels. However, there is limited data showing the chronic effects of HNHF-O2 in patients with hypercapnic respiratory failure, specifically those discharged to home following hospitalization for an acute exacerbation. Data that demonstrates that HNHF-O2 is well tolerated, and stabilizes or improves gas exchange long term in patients with COPD is lacking. Similarly, data that demonstrates that this therapeutic regimen is feasible to provide to patients in the home environment are lacking. This is an open-labeled pilot study of thirty patients to determine the safety and feasibility of using the device in the outpatient management of patients with COPD. A subset of ten patients will have serial sleep studies to determine the effects, if any, on sleep.