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Airflow only goes to one bedroom

345 Views 2 Replies 3 Participants Last post by  eggs
Hi All! I'm new to this forum. I have some DIY experience but little in the way of creating or altering ducts. I wanted to get a second opinion here on what I need to do to fix my airflow discrepancy between rooms. Below I am attaching a HVAC
drawing of my apartment. The red lines are covering an air handler that seems to work fine. The second air handler is where I have problems. I would say that about 90% of the airflow travels and exits through the branch marked number 1. and 10% of the airflow is split in between the two number 2's. A few additional problems with this airflow discrepancy is that the thermostat is in a room that gets air flow from duct number 1 and the room that gets air from duct 2 is facing east with large windows and with the door closed in the morning and during the day that room can be 10-20 degrees warmer than the rooms fed by duct 1. I think the problem is that branch 1 is too close to the end of the main duct and does not create any back pressure so all the airflow goes to duct 1. My Idea is to place a damper at the beginning of duct 1 to create backpressure and airflow for all the other branches. Will this be a good idea?

Thank you for all the help, everybody.

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See if here is already damper on that closed area 2 and needs to be opened. If you close all registers on zone 1 does zone 2 gets more air?
Your issue is proper air balancing. With a manometer you can trouble shoot and figure out your problem. With out one, you will be batting at straws. You will need to know static pressures in several spots of the duct work. This will identify where you problem is, then we look for dampers or restriction in that trunk. Duct sizes are also important in systems. This requires a duct calculator, helps decide duct sizes through out the system. If the duct sizes are wrong, it will be much harder to correct. Just tossing duct work up not knowing what you are doing only causes more issues, thus why left up to professionals. If you want to go down this path, I can help - just let me know...
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