My work as a designer would be a lot easier if every interior were free of structural impediments. But that would also make my job less fulfilling, because meeting the challenge posed by an exposed heating unit or water system does bring its own rewards.
A standard solution to the problem of intrusive elements is to ignore them. Many people believe that if a thick drywall beam is painted the same color as the ceiling and walls, it will somehow disappear. Sorry, it just doesn't work.
Instead of trying to camouflage a large functional element, I regularly take the opposite approach: I emphasize it.
A beam, for instance, can be turned into a lighting valance with a few easy alterations. And that duct over in the corner -- the one covered in drywall to form a pilaster-like projection: How can it possibly be disguised? It can't, so my strategy might be to cancel it out by introducing a similar object in the opposite corner.
Such an addition would serve no functional purpose, but it would achieve the goal of creating symmetry. And that might lead a viewer to assume that the two pilasters are structurally integral to the space.
Don't listen to those who say that decorative moldings can only be used in a traditional manner. In an already-disjointed setting, unorthodox use of moldings may be just what's needed to provide coherence.
The photo shows how a few architectural fragments -- antique columns and pilasters in this case -- can much improve the look of a space previously plagued by unsightly duct work. The dentil molding further enhances the room's elegance. It's a perfect complement to the furnishings.