I have an upflow propane furnace in my basement and plan on installing my hx in the main vertical plenum, about a foot above my a-coil, right below where it hits the horizontal trunk that feeds the whole house.
The vertical plenum is about 20" x 20", but I don't think a 20" x 20" hx would fit in that space, too tight.
Would you use a 19" by 20" in this situation?
Do you just attach a couple of small pieces of sheet metal angle to the insides of the duct to support the hx?
Also, it seems that all the hx inlet ports I have seen are sweat connections. Do I need to use a threaded adapter that sweats inside (male) the ports, outside (female), or does it matter?
I am a total greenhorn when it comes to sweat soldering but it's time I learned.