If you feel warm air coming and going behind a wall in your bathroom during your remodeling project, there are a few possibilities for what it might be:
Heating Duct or Vent: The warm air could be coming from a heating duct or vent that is located behind the wall. Heating systems in homes often have ductwork that distributes warm air throughout different rooms. If there is an opening or gap in the wall, you may feel the warm air escaping from the duct and entering the bathroom.
Hot Water Pipe: Sometimes, hot water pipes run through walls to supply water to fixtures like sinks or showers. If there's a leak or a poorly insulated hot water pipe, it could be heating up the air behind the wall, causing the warmth you feel.
Electrical Issue: In some cases, warm air might be an indication of an electrical problem. If there's an electrical circuit or wire running through the wall and it's experiencing some issues, it could generate heat and cause the wall to feel warm.
Adjoining Room's Heating Source: If the bathroom shares a wall with another room that is being heated, some of that warm air might be seeping through gaps or openings in the shared wall.
Sunlight Exposure: Depending on the orientation of the wall, it's possible that sunlight is hitting that specific wall, causing it to warm up.
To investigate the source of the warm air more accurately, you should inspect the area carefully. It's important to ensure that there are no safety issues, such as electrical problems or leaking pipes. If you're unsure about what's causing the warmth, it's a good idea to consult a professional, such as a plumber, HVAC technician, or an electrician, to assess the situation and provide appropriate recommendations.