How To Add Vent To A Duckboard Ac Trunk Line

2 Answers ii

I adore the cartoon of your existing duct-work. Using a .i" external static resistance for the duct-work and guessing that you have a iii ton A/C organization that requires 1200 CFM of air flow, I would estimate that the eight"X20" duct is almost fully utilized every bit is the eight"X8" duct. The eight"X14" duct could handle all the airflow required for the basement heating. You lot did say that y'all wanted to utilise the viii"X20" duct for the basement heating. You tin do it merely it may unbalance the existing airflow. You lot may have to increase the blower speed to attain the required air flow in that duct and add dampers to the other ii ducts to aid control the increased air menstruation. Adding 4 heating registers would crave approximately 320 CFM more air flow you may or may not have bachelor. I would add the ducts you require and balance the resulting arrangement as all-time I could and alive with the results. If the blower that is installed in your present heating system is sized for more air menses and a college static head than I allowed for say yous could easily add together the iv registers you will demand. If on the other hand your blower is maxed out the system will still rut just the 2nd. floor heating may suffer. This is the best I can do since I am non at you residence and I am simply guessing as to the existing prepare-upward. good luck with your project. I call up that you will exist OK. I compared your home to mine 2000 sq. ft rqnch and finished basement. Mine heats great.

answered December 27, 2017 at 21:01

d.georged.george

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I forgot an item, what is the size of your A/C in btu's or tons and what are the last digits of the furnace's model number which tells usa the furnace input? If yous take more than iii tons of A/C calculation ducts to the 8X20 duct may not be feasible.

December 27, 2017 at 23:21
Total furnace model #: 59SC2B080S1712-16

Dec 28, 2017 at 12:12
The Air-conditioning unit is 3-tons.

Dec 28, 2017 at 12:23
You should exist OK on adding 4 ducts to the 8X20 duct and if you have A/C they would probably exist closed or mostly closed when the A/C is running.

Dec 28, 2017 at 12:23

You lot tin certainly add together as many ducts every bit you lot like, the more the merrier in fact as far as your equipment is concerned. The only problem you may see is balancing the entire system. Bold the ducts were sized correctly in the beginning identify you will be taking air from the other ducts on that trunk line. The furnace is nevertheless putting out the same amount of air for the about part simply the distribution will alter. The merely fashion to clinch proper distribution is to get-go do a Manual J load calculation so a Manual D duct sizing calculation (or equivalent) Anything else is guessing. Short of that yous could install dampers in all the branch lines and close them every bit necessary to try and balance the system. Full air flow should then be measured to make sure yous haven't closed likewise many dampers.

answered Jan 6, 2018 at 8:12