What causes this pattern on finished wall?

1958 Full brick split level, remolded in 2009. Pattern seen in one bedroom East side, nail pattern seen on painted wall. Top of wall where caulking is cracked shows dark areas. I’m thinking air movement at top but not sure why you can see the drywall nails through painted walls. Any Ideas?

Remodeled but probably not insulated. Ghosting. From the heating duct above the window. Oil heat maybe?

Gas furnace

Ghosting… http://inspectapedia.com/interiors/ThermalTracking.htm

*http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/98/980109.html *

You’re definitely seeing the framing members, most likely caused by thermal bridging of the wood studs creating ghosting, doesn’t matter what kind of heat

Glenn is right on!

Yes and no. Older oil furnaces put out many more impurities into the home than newer oil furnaces. This unit is 55 years old and if the burner and firebox have not been modernized / updated since installation, they are putting out many more impurities into the air in general. Those impurities can leave a darker stain in the same ghosting areas that a gas unit or electric forced air unit. When we replaced my 54 year old unit, there were 1/4 inch cracks on 2 sides of the heat exchanger that were not visible until most of the unit had been removed.

Nice pics, I wonder if you could have confirmed a lack of insulation through an outlet or switch. I’ve never seen ghosting in between the studs like that.

I had that about 3-4 years ago and insulation was missing.

Pics are a little fuzzy, what are the chances that they occupants liked to burn candles?