Plenum design

[razcob]

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?

[air2spare]

Get you post count up and apply for pro status, you'll get more help

[energy star]

First thing to do is rip that whole mess out (duct)

[air2spare]

First thing to do is rip that whole mess out (duct)


:ditto: ....and AMEN!

[genduct]

WOW, talk about Rube Goldberg and going around your elbow to get to your behind!
Don't understand where all that stuff is going but I doubt the air knows where it is supposed (expected) to go. For starter it looks like you need to extend that short plenum up 4 feet or more so you can grab those side hits. You may even need a divided flow fitting to get the air to go back down toward the floor to where ever its trying to go.

Without a real sketch and CFMs It is all a big guess. I'll bet you College course was all about the refrigeration cycle and not much about airflow.
You can use my email in profile If you would like to speak some more

[zzonko]

Ummm what did they cut that hole with? a pliers?

[energy star]

It will all be OK. Very simple to fix. I'm just not sure I can say much with you having only one post. I usually just wait until others give descriptive advice. So when that happens, I may chime in. You will have many ideas. Congrats on finding the best HVAC forum around.

[tinner73]

that's fine as is...leave it alone.