It's elementary physics, my dear Watson, elementary.
Heat seeks cold. Everyone thinks that heat rises. Well, it does! If it's seeking cold. If the cold is down, heat sinks!
As a Boy Scout, along the C&O canal, near the Antietam Battlefield, there is a large cave. It goes way in and eventually way down. It is full of bats! I have been all through it. Inside we could always tell which way the opening was, even way inside, because we could feel the July heat from that direction! As a 14 year old I marveled at that, not understanding the physics of it all.
This is what whooshing heat looks like from inside the room.
That is a small alcove behind the bureau in a very cold bedroom.
The studs are clearly defined in the walls and ceiling.
The purple areas are the colder spots - about 48F.
This is an exterior wall, with brick siding. The insulation behind the drywall has clearly settled, pulled away or was never placed there when the house was built 15 years ago. The warm/cold lines are very uniform. I think there is no insulation there.
And that will influence a room!
Sometimes aspects of the ceiling were not insulated properly, or it was removed to do a repair and not replaced well. Or at all!
And when that happens, this is what it looks like from the attic side.
The ambient temperature in the attic is 14F. So it is cold out.
You are looking at the flat drywall of a ceiling directly over an elderly woman's bed. She is cold at night. No wonder! This is uninsulated drywall! Her room has insulation gaps everywhere - walls, ceilings, and the clothes closet was nearly devoid of insulation! It was 41F in that closet!
That drywall is 71F. The ambient temperature of the room below is 60F and the hallway outside is 76F. They have the heat turned up to try to warm Mom's room.
This is heat going whoosh from the room.
Where is the heat going? TOWARD COLD! And anywhere it can.
My recommendation: the R-value of drywall is not much - about .45 for 1.2" drywall! Don't count on it to keep your house warm in winter or cool in summer! Insulation is the cheapest and most effective form of energy savings you can do, well, perhaps after caulking around windows and doors! If you have hot and cold rooms, have someone check it! Consider adding to it if you need! It's elementary...
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560