I will soon be running wire for a heat pump I am having installedI need to run 2 6-gauge thhn, 1 10-gauge thhn wires in a conduit from the panel to where it will be hooked up to the furnaceI have a fair bit of electrical experience just not running something like this before.I'm wondering how this is generally done and have a few questions- What size conduit would be best to accommodate those wires? - Would installation in the attic or crawlspace be better? - If in crawl can i strap the conduit to the bottom for the rafters? Then go up into the rafters to cross a support wall in the center of building?- If in the attic can i run it over the rafters with out issue? and the same go down into the rafters cavity?I can easily install it either in the attic or the crawlspace but was not sure if there normals of how its installedThanks in advance!
To pipe, or not to pipe? If all the other circuits in your house are in pipe, go with 3/4 EMTIf not, then NM (romex) is indeed easier to runTrouble is you can damage the insulation driving the staples down on itRodents like to chew on itAnd If more than 4' from the tie beam you need to place a board along side it to prevent damage(We call that a Rat Run) EMT needs to be strapped within 3' of each connector (box) and every 10' there afterIt is OK to put straps closer than thatRomex needs to be strapped within 12 of a box and every 4' there afterIf you feel more comfortable working on your knees rather than on you back, go through the atticBut either route is fine.
Fiberglass is the bestYou can either go with batts or loose fill, which is blown in14 of loose fill gives you R-38, as does 13 of battsHope this helps.
