I am trying to add radiant floor heat to a old room that had electric baseboard heater. I currently heat the rest of my house with a pump driven boiler with radiant heat. I would like to tap into this existing system. But because of the allowable space in the new room. I am only going to be able to use 1/2 pex tubing. The rest of my system is running on a 3/4 copper pipe. I want to cut out a section of this 3/4 pipe. Run it into the 1/2 inch pex and back into the 3/4 pipe returning to boiler. Is this going to work or am I going to have to try something else?