Daniel is in the process of constructing a studio in his backyard, and the dimensions are depicted in the figure below. Daniel is considering using a window-unit air conditioner to cool the studio. To determine the necessary BTUs for effective cooling, he follows the guideline of 3 BTUs per cubic foot for well-insulated new constructions. If Daniel chooses this method of cooling, what is the least amount of cooling capacity he should seek when selecting a window-unit air conditioner?