FurnaceCompare.com reports that Dunkirk's popular Quantum 90 line furnaces have the most positive reviews, as of 2015. The Quantum 90-200 series follows the Q90 series in positive reviews, followed by the Q90-100 series which ranks third on Furnace Compare.
Information on individual furnace units' specifications can be found on Dunkirk.com. They offer several different models in addition to the Quantum models for individual needs. Model functions vary; additional information pertaining to each model can be found on Dunkirk's official product pages. Dunkirk can also be contacted through their site or over the phone for unlisted information, questions, and further recommendations through their site's Contact Us tab.