THE KNOCKDOWN CENTER This refurbished 19th-century brick factory compound at 52-19 Flushing Avenue (at 54th Street) in Maspeth, Queens, initially produced glass and then prefab, or knockdown, doors. Now, four years old, it is its own kind of strange hybrid. Overseen by the artists Michael Merck and Tyler Myers, it survives by renting parts of its 60,000 square feet for weddings, performances and other events. But along with Vanessa Thill, the two also oversee noncommercial art exhibitions. The best of the three current shows is “Transactions,” organized by Carolina Wheat and Liz Nielsen, who run Elijah Wheat Showroom, a small Bushwick space. They invited artists to contribute a favorite object and explain its importance. Nearly two dozen responded, including Carol Bove, Lisa Yuskavage and Yevgeniya Baras, and their often telling selections hang above little rugs and pillows that invite intimate contemplation. One of the most tangible effects of this barely-visible show is the hand-drawn map by Mr. Merck. In the courtyard, the capable sculptures and paintings of John Furgason, Serban Ionescu and Carlos Little all gain from being displayed in a romantic ruined boiler. A two-person show introduces the work of Anna Mikhailovskaia, a promising young Brooklyn sculptor, and John Schacht(1938-2009), a little-known Chicagoan, whose watercolor-gouaches of patterned biomorphic forms expand the legacy of the Hairy Who. The Knockdown Center brims with unrealized potential. It already has a restaurant.