Well, I have asked my builder to run the dryer vent pipe under the bathroom ceiling and out the side wall, so that the pipe is inside the conditioned space. The project manager just told me that the HRV crew already ran the pipe through the attic space before he could instruct them.
So, he's asking me whether I want the pipe moved to inside the heated space and vent it to the outside wall from the inside. Now, that they have the pipe in the attic space and wrapped in insulation and a hole punched on the side wall, I'm contemplating whether to leave it or get them to change it.
Here's the picture of the space with my artistic attempt to draw the options.
The red shows where they ran the pipe and the green shows where I wanted to run it. Running it inside the bathroom would mean cutting across the shower stall and adding a bulkhead around the pipe and then vent it directly to the outside wall with the window. It's not preferable for aesthetic reasons, but I made the decision to do it anyway in the name of efficiency!
This bathroom is on the outside corner of the main level. Meaning the wall behind the laundry stack and both shower walls are exterior walls. There is no heated space above the bathroom, just the attic. Attic insulation will be R50 and it has a raised heel truss design. The builder said that currently the pipe would be sitting inside the blown attic insulation once they add it. That means there would be a 4" hole in the insulation, but the pipe condensation risk should be minimized.
So, I am just thinking about the heated escaping up the pipe into the attic. Do you think I should ask them to change it and move the pipe from the attic inside the bathroom space or not worry about it? Does it make a difference if there is a hole punched in the outside wall of a heated space or in the ceiling?
Thank you!