Trying to Understand my HVAC Distribution Issues
Live in Florida, 2800 sqft home.
I had an AC company replace my my condenser and blower last year. I believe they went too large, but house still struggles to stay cool. Additionally, the blower is sweating profusely. It's in an unconditioned Florida attic.
So I went up and took inventory and with the help of this post (https://russellking.me/2017/09/06/how-to-quickly-evaluate-a-residential-hvac-duct-layout/). I made the attached excel document to understand where I am. It appears that my main trunks are WAY undersized for the size system I'm using. However, the drops seem adequately fed.
Explanation of the document - each branch shows the size of the actual vent and theoretical CFM allowed/required for that size. The colored text below that is the actual CFM allowed through the branches nested/hanging off that branch.
House struggles to stay cool on hot days (which is everyday in the summer). I know I have problems with the degrading condition of the flexible ducts and the supply plenum. My plan is to replace all of that and bury the attic in blown in insulation.
My question is, will simply upsizing a couple of these trunks rectify some of the sweating? I fear that the trunks which allow for 1320 CFM on this much larger system are causing serious static pressure at the supply. Is this a correct assumption? If I upsize the trunks, say - upstairs trunk 2, do I then need to 'upsize' the drops hanging off of it?
Thank you in advance.
Posted Aug 11, 2024, 6:39 PM UTC