pex info needed

[dave_dj1]

I'm about to install a self built loop in my outside hot air wood heater. My question is for you pex experts, if I hard pipe the pex at the furnace end and allow for expansion inside will this be ok? I have heard that pex will grow and I don't want it to grow on the outside end, if it grows on the inside end that will be fine.
thanks,
dave

 

[H-Ranch]

You're talking if it expands inside the house? Mine grows by as much as 2' over a 75' run or about 1.5% at 150F. The higher the water temperature the more it will expand. You can probably find the expansion rate with a search if you're looking for an actual value with temperature range. I have a 90 degree bend in mine to allow for movement where it enters the basement (it's 90 degrees when it's running and somewhat over 90 degrees during the off-season.)

 

[dave_dj1]

Good info, thanks.
I just don't want it to move/grow at the stove end, I don't know how to compensate for that end to move. It's no big deal if it moves inside the house.
Thanks again,
dave