I am a new member, but have a college certificate in HVAC. I plan on doing this work full-time, to supplement my retirement salary. Over the last few years, I have hired a duct specialist to handle any duct work that may be necessary. However, I would like to tackle installing a plenum, on this unit, if I could get some suggestions from this group.
The AH is a Rheem variable speed with a supply dimension of 10 5/16 by 19.5 inches. The vertical duct and right side supply ducts are 12x12. The plenum box is 16L x 20w x14h. The 6 inch hole was for a supply to the room over the garage. I am considering installing a 6 inch takeoff, w/scoop to the vertical supply duct, because the homeowner says the room over the garage doesn't heat/cool very well.
Do you have any suggestions for a custom plenum design that would increase the flow to the two main supply ducts?