I'll follow cyberwollf's lead and throw in another non-homebrew plumbing question.
My neighbor came over to ask me to take a look at his new furnace installation. He's not too happy with it, but I don't have any answers so hoped someone here could help. Lots of questionable workmanship, but the biggest concern is the reduction in pipe size. The house is a pretty big ranch with one zone. The main pipe exiting the old furnace and running through the house was about 1-1/2" diameter. The pipe coming out of the new furnace is the same size, but for some reason he reduced it to what looks like 1" for the short runs he made between the furnace and the existing plumbing on both the in and out lines.
Is there a reason for this or did the guy just cut corners and use the pipe that he had available. The installer was a private subcontractor hired by Sears to do the installation.
You can see the four points where the pipe goes from big to small in this picture.