I have had cooling problems last year and had several contractor coming in to tell me what they thought was wrong with my system.
Only one was able to show me (with a remote monitor) why my second floor was not cooling.
There are no ducts going from my returns to my unit in the basement! In all rooms i can see the return openings but the video showed no ducts.
So no matter how much air the fan pulls, it is never coming from the second floor.
Now my question: can I somehow add ducts without opening each single wall from the socond floor to the basement?
Could I run one main duct to the attic and split it uo from there to my bedrooms and hallway?
Or would it be better to add an additional, smaller unit in the attic that will only cool the second floor?
Heating is not a problem since hot air rises and I don't want my bedrooms too hot anyway.
Thanks in advance for your advice,
They may have used the space between the studs and drywall for the return, not installing any metal duct. While this is allowed by code in some places, its not the most 'elegant" way to duct a system. You need to test if there is any actual air flow to these returns. You can do this by holding a burning stick of incense near the duct. If the smoke is pulled in, the duct is connected to the furnace.
Is this new construction? If so, your problem could be as simple as not having the system balanced. There should be adjustable dampers in the supply ducts that allow you to regulate how much air goes to each room.
My other question is, what did the other contractors reccomend?
Getting a two story house to both heat and cool equally with one system is hard, it defys the laws of physics. In the summer you need more air upstairs, in the winter, you need more downstairs.
Zoning, with automatic dampers can make this happen.
i think it would be cost effective to install a unit in the attic for the second floor
at night you can run only this unit to sleep and save money on cooling in the long run