Need help..2nd story zone wont cool.

[KStarkey]

My home is 9 years old. The GEO unit over the years has been having more and more problems cooling the 2nd story. The house has 4 zones. It freezes us out of other zones trying to reduce the temp in the upstairs zone. I have adjusted temp ranges to put most of the overflow cooling into the basement. (the least used part of the house) It does fine heating, it's only the cooling. Any suggestions on what my problem might be?

[AMI Contracting]

It sounds like a classic poorly designed duct system.
Code minimum ducts to the second floor are not easily compensated for with just a few dampers.
You are correct that dumping is the easiest fix.

[KStarkey]

Dumping extra cooling to the basement just doesn't cut it on the hottest days. I'm wondered if I need more venting in the attic. If adding more insulation on the duct work would help. Also the possibility of adding an inline duct fan. Do you think any one of these is a better option? any other ideas?

[engineer]

Inline blowers and added duct insulation are band-aids at best.

Do it right with a cooling load calculation for the problem rooms and measurement of the air flows into them

[mtrentw]

Instead of trying to push the cool, you may be better served getting more hot return from the hot zone.

[geome]

My home is 9 years old. The GEO unit over the years has been having more and more problems cooling the 2nd story.

How did the system cool the 2nd floor when the system was new?

[engineer]

It could be as simple as a failed zone damper

[Mark Custis]

so I did not respond until Trent, engineer and Geome hit the points I would have made. I would need more information on how the home is zoned and the size of the duct work to the hot area.

At 9 years old it is possible that blown in insulation is settling.

Keep us posted.

mark