Help troubleshooting TT AC airflow

That is because you have increased the static pressure in the system to the point that the blower can no longer move the air. Keep all the registers open. If you have an area that has low airflow; first check that the register there is properly sealed to the main duct. In fact it wouldn't hurt to check all of them. Depending on how the duct work is laid out you may be able to add an additional register in the bedroom area.

I may be misunderstanding, but the main "VENTS" in the unit, I would take as the return vent also? Obviously, that will not work. The unit needs to breath, as it is a closed system. The fan can only push so much air through the small ducts. Are you sure your bedroom ducts have no blockage, or leak into the ceiling? I can notice a big difference in flow to my bedroom ducts, just by closing the direct quick dump on my 15K unit.

Jerry

prichardson wrote:
That is because you have increased the static pressure in the system to the point that the blower can no longer move the air. Keep all the registers open. If you have an area that has low airflow; first check that the register there is properly sealed to the main duct. In fact it wouldn't hurt to check all of them. Depending on how the duct work is laid out you may be able to add an additional register in the bedroom area.

yup, you need a minimum open area for the vents. and most trailers ONLY have enough vents when open to meet that minimum area. so closing them really seldom increases airflow noticeably.

Right. The "dump" vent on the unit itself should be closed except when you want extra airflow in that immediate area.

The other possibility is that your cooling coils are so trashed that not much air can get through them.
coil cleaner
If the coils are too dirty , air can not pass through them fast enough.