We recently received a call from a long-time Levittown customer in North Park that was concerned about black marks on the walls above his baseboard heaters. This is referred to as ghosting or thermal tracking, which is a relatively common phenomenon that plagues both old and new construction. Here’s a look into the causes and some things you can do to prevent it.
The dirty streaks that can appear above your baseboard are mostly created by dirt, dust or carbon soot from a number of sources like fireplaces, cigarette smoke, pets, cooking byproducts, etc. that are spread by the natural convection created by the heating cycle. If the warm, dirty air from the baseboard heater comes in contact with a cool wall or one with a higher moisture concentration the dusty particles are deposited.