It’s a common challenge faced by HVAC contractors across the country: In order to maximize living space, many new-home builders banish furnace and air conditioning units to small, remote closets — or, worse yet, to inaccessible, unconditioned corners of attics and garages.

While it may not occur to homebuyers at the time of purchase, and perhaps not even to some architects and builders, these space-saving techniques can cause numerous problems for homes, their owners, and the contractors who all too often must come up with corrective solutions.