Import Water To Air Hanging Heat Exchanger 20" x 20" While we encourage you to purchase American made products, we also provide imported hanging water to air heat exchangers at a lower price than our American Made versions. These units will be of a slightly less quality then our standard hanging water to air heat exchangers. Hanging Units are great for Heating garages, greenhouses, workshops, and basements • 160,000 BTU, 20" x 20" • 16ga Material • Unit Is Imported from outside the USA