How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Rick Your Own Question
Rick, HVAC Supervisor
Category: HVAC
Satisfied Customers: 21805
Experience:  40+ yrs. experience as a licensed oil & gas technician.
Type Your HVAC Question Here...
Rick is online now
A new question is answered every 9 seconds

I'm reworking my heating duct, and I had a question about

Customer Question

I'm reworking my heating duct, and I had a question about proper sizing. Currently, there are 2 branches of 10" flex duct going to 3 rooms each.I plan on changing this all to rigid, but have just one branch to 6 rooms. Will this be adequate or do you suggest to do 2 10" branches like it is currently setup?
Submitted: 1 year ago.
Category: HVAC
Expert:  Rick replied 1 year ago.
Welcome to Just Answer, my name is ***** ***** I will do my best to help you with your issue. If my initial response doesn’t answer your question then let me know and we can continue our conversation.You need to maintain the same cross sectional area that you have now 2 10" round is barely big enough to handle 6 rooms. If you want to do it with 1 branch the duct should be ~160 sq. in. (8' x 20" if you use common prefab sizes )
Customer: replied 1 year ago.
I see. So definitely, stay with the 2 branch lines then.The previous contractor used flex duct for all connections, including the branch. By changing to rigid, would my airflow be better? It's very limited right now.
Expert:  Rick replied 1 year ago.
Changing to round rigid won't make a significant difference as long as the current flex is not squashed at any point.
Expert:  Rick replied 1 year ago.
Do you have any more questions?
Customer: replied 1 year ago.
Hi Rick. Can you please pass me on to a different expert so I can get another opinion? Thanks.
Expert:  Rick replied 1 year ago.
If you'd like a second opinion please post a new question on this topic
Customer: replied 1 year ago.
I'd like to know the benefits of flex duct vs rigid duct... Again another experts opinion.Thanks.
Expert:  Rick replied 1 year ago.
The site requires that you post a new question if you want a second opinion. The advantage of flex over rigid is that you don't have to insulate flex and it's easier and cheaper to install. There is no meaningful difference in flow between the 2.If flow to these rooms is inadequate there are likely other issues at work. They could include, inadequate return air capacity, inadequate blower capacity, poor overall duct design.