Heating Help

Changing 5 ft of 1 Inch copper to 3/4 inch pex

Can i change 5 ft of 1 inch copper out to 3/4 inch pex to move the pipe for visual reasons?  I have a loop system and would like to move a pipe that is running over head thru my finished basement.  it is about 5 ft long and at the beginning of my downstairs heating zone.

Copper to PEX

You can do whatever you want. No one is watching.
However, pipes increase as do their squares.
That neans that it takes 4, 1" pipes to equal a 2" pipe. And it takes 4, 3/4" pipes to equal a 1 1/2" pipe.
And I think that 3/4" PEX has a smaller inside diameter than 3/4" copper tube.

pipe size

Ice is right. You get about half the capacity if you use 3/4". Why not use 1"? If you don't have a 1" pex tool, you can use "SharkBite" fittings that transition directly to copper. Make sure that you use Oxygen Barrier pex, not the regular pex that is used for plumbing.

If you have a Monoflo system, then chocking down the loop to 3/4" is really not a good idea. You also better know how to purge and bleed the air out or you'll be having alot of hydronic head aches.