H.O. question...

[bluesy]

...been here in SE Michigan 25 years. I had a new gas forced air furnace/air cond. installed last October. Heated fine all winter. It's cooling fine right now. The issue is the basement. It's finished; large main area, (4 registers/1 large return) ,1/2 bath (1 register), good sized furnace/hobby room (no registers or return), and tv room (2 registers/1 return). There's a door at the TOP of the basement stairs. All the registers in the whole house are wide open. Humidity up and down is comfortable- although a tad higher in the basement when the air doesn't run a lot. The issue is-you'll freeze in the basement! How do I even out the temperature? Shut the basement registers and leave the door open? More return in the basement? I don't know. I'm fairly broke as far as calling the installing company back to "investigate". Anything I might consider? Thanks for the great forum.

[bluesy]

...just wanted to add that the old system was the same regarding it being cold in the basement in the summer with the air running.

[beenthere]

Close the supplies in the basement.

It doesn't take much to cool a basement.

[snupytcb]

is the basement ceiling insulated

[bluesy]

...the ceiling is not insulated. It's a drop ceiling. So, you think shut the basement registers and the door at the top of the steps?

[beenthere]

I'd try it with the door open, and with the door closed.

[RyanHughes]

Close the supplies in the basement.

It doesn't take much to cool a basement.

Just wondering: Could that cause backdraft/negative pressure issues with gas in the house? I just see a negative pressure possible with the supplies closed and the large return in the basement. I also have 4 (open) supplies and a return in my basement, which is finished. I have electric, so the backdraft isn't a problem, but I am curious still.

[beenthere]

Thats why I said to try it with the door open, and closed.

Plus he said the furnace room has no return in it.

[bluesy]

...the door open or closed thing- with the door open, more cool (conditioned) air rolls down the stairs-back to the basement return, right? That seems like it would help keeping humidity in check down there but it would still be cold. with the door closed, would the basement return "pull" as much downstairs air back through the return?
Seems like with the basement registers closed, and the door closed, I might not return as much basement air to the unit. That might leave it warmer down there but might give it a chance to build up humidity. Yes, no?
The gas water heater is in a separate room with a door and no registers or returns.

[beenthere]

The coldest air from teh first floor will go to the basement with the door open.
But the air won't be 50* air like it is out of teh registers. The return will remove higher humidity basement air and help to keep it dryer in the basement.

With the door closed. Your basement may become too humid. Depending on if the door is sealed or not. and if your returns for your other floors are under sized or not.

Try it each way.