Goodman replied to my e-mail- Dear Darren Miller, Thank you for contacting Goodman/Amana's Consumer Affairs Division. The technical support department has advised that there isn't a direct specification regarding distance but they do recommend at least a 3 foot distance. If you desire additional assistance, please contact our toll free line at: 1-877-254-4729 and speak to any of our Consumer Affairs agents. Thank you, Michelle Weatherly Consumer Affairs 1-877-254-4729