"jamesgangnc" wrote in message
...
On Aug 4, 11:46 am, wrote:
On Aug 4, 9:13 am, Yong Huang wrote:

Thanks. More than half the time at night, the AC is not running. I
hope the room is not too warm during that time. I'll try to put more
insulation in the ceiling above this room.

That will make it WORSE by trapping the heat that is rising up from
the driveway below!

No, it won't. The room is already conditioned space. It is not
conducting heat from below the floor, thru the room, and out the
ceiling.

Improving the insulation below the floor would be more effective but
I'm assuming that space is unaccessible from above or below without
major demolition. In most cases the space above is easily accessed.
Improving the insulation up there, while not as effective, would still
reduce the overall heat transfer between the room and the surrounding
unconditioned spaces. Anything that does that will reduce the load on
the hvac service to the room.

Is it possible you don't know what you are talking about?

===

heh By the same logic he could drill holes to let the heat out g

I was going to suggest a register assist fan or larger duct. Insulation
never hurts. Another thing would be to check the condition of the duct work.
I have those insulated tubes, and in one of my main tubes, the insulation
collapsed inside the tube blocking the air. Easy to check, the tube will
collapes when the ac isn't running or feel mushy when squeezed.