Proper Selection & Sizing of Return Air Grilles

[@Wilderness-Improvised]

Excellent work and Explanation dear! Good luck.

[@jefftee448]

Stupid question, cuz ive got to missing something hen calculating the Core Are Return Grill for a 18x10 grill = 18 in x 10 in = 180 inches^2 So when converting to feet (12" = 1ft) , why are you using 18" instead of 180? From my calculations it looks like its 180" / 12" = 15 feet. But in reality, 15 square feet doesnt sound right. EDIT: Nevermind, I knew it was something stupid I missed....you converted to feet first (18/12)*(10/12) = 1.25 ft^2

[@mohammadaliamiri5335]

بسیار زیبا موفق باشی خالق جان

[@apsalmofdavid]

Can you please share the table and documentation you use? Thanks.

[@iamEmanSWK]

Hi, would you be able to share the table with me as well? Thanks.

[@Espiritiv]

I have some questions that seem straight fwd, but confusing too! I have a group of (3) Diffusers i want to use that say its max CFM is 145 each for a 12x4 unit. The Plenum box they can supply with it says it only has a 6" duct. To me this in no way would exceed 75-85CFM. So Would i size my return grill based on this max CFM of the duct from the supplies?

[@theengineeringtutorial2290]

Yes, based on the maximum CFM of your supply

[@Espiritiv]

@@theengineeringtutorial2290 Thank you! My engineering brain told me that was correct but the guys selling the vents wanted me to size my return based on the max cfm of the supply registers, not the supply ducting (which is less). Their way would cost me more with a larger return grill.

[@ericg.magnaye6899]

Thanks it's really helpful..

[@TanweerAhmed]

Informative

[@ericg.magnaye6899]

Can you please share the table you use? Thanks

[@theengineeringtutorial2290]

Yes, no problem, the tables will be sent to you through your email soon.

[@ericg.magnaye6899]

@@theengineeringtutorial2290 send to [e-mail] thanks

[@thomasconklin7471]

@@ericg.magnaye6899 Could I get a copy of that table as well?

[@rat.y]

Can you please share the table you use? and why we need to divide by 0.5 sq.in .thanks sir

[@theengineeringtutorial2290]

1 CFM / 0.5 to 1 square inch of core area is just a rule that will allow you to maintain your air velocity suitable. So if you use 1 or more CFM for less than 0.5 square inch your return air grille will liable to noise or undersized and if you use 1 or more CFM for more than 0.5 to 1 square inch of grille that will be oversized. Some More rules for selecting return grille other than this rule has been also already explained in this video, can used be used to solve your problem.

[@rat.y]

@@theengineeringtutorial2290 Thanks bro..can share the table chart you use and email to [e-mail]

[@joginderkajal3436]

Very nice

[@kannu8019]

Means of - NC 20

[@kennybakerhvacr5751]

Hair Andler? Lol.good video but I can't not hear that lol

[@robertgranafei2781]

Sounds just like an engineer ; totally confusing.

[@correctingculture]

If youre in hvac, please disregard this video. He's WAY off