Very possible there is a damper in the cellar that is partly closed.
Here is a picture of the ones typical near me.
http://www.hvacsolutionsdirect.com/i...lar%20AR-1.JPG

If the handle is in line with the tube, it's open. Across, is closed.
Two adults with walkie talkies can trouble shoot that pretty quick.
Sometimes if the adult upstairs bangs on the duct with a metal screw
driver, the one downstairs can tell which duct it is. Yelling into the
duct from above can also help pinpoint.

--
Christopher A. Young
Learn more about Jesus
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..


"annur" wrote in message
...
My tenant recently complained about one of the bedroom upstairs being
too hot. When I checked the vents in the floor (there are 2 vents) in
this bedroom, one of them has more air blowing than the other one. I
also checked all the rooms, and there is more air blowing on all of
them. Except this one vent in the bedroom does not have enough air
blowing. For this vent that has a problem, I opened the vent and
checked if there is anything stuck which I did not see and everything
seems to ok as far as I know. Is there something I can do to fix this
problem?


Thank you very much for your help.

Annur

Worst case, if you can't find a control damper somewhere in the
ductwork, replace the existing grill with a new one that has a damper
on it so you can open or close the grill.

On May 19, 8:09*am, Mikepier wrote:
Worst case, if you can't find a control damper somewhere in the
ductwork, replace the existing grill with a new one that has a damper
on it so you can open or close the grill.


Trace out the path from that register back to the main duct or
furnace. First, make sure that nothing has come disconnected. It's
common for taped joints to come apart and either leak badly or fall
apart completely.

As others have pointed out, it's possible you will find a flap in a
duct that controls the amount of air going to that register. If so,
if it's not fully open you can adjust it.

It's also possible that this particular run is farthest away from the
blower, is long, more turns, etc. For that, there are a couple of
possible fixes. One is the type of add-on blower that just sits on
top of the register and gets plugged into a wall outlet. It senses
when the system is on and turns itself on, pulling air out of the
register.

The other is an auxilliary blower that gets inserted into the duct
section going to that register or perhaps a couple of registers on the
same section that need more volume. The blower is powered off of the
furnace blower or with a sail type switch in the duct. I installed
one of those and it made a significant difference in airflow in the
upstairs bedrooms farthest from the furnace.

On May 19, 9:15*am, wrote:
On May 19, 8:09*am, Mikepier wrote:

Worst case, if you can't find a control damper somewhere in the
ductwork, replace the existing grill with a new one that has a damper
on it so you can open or close the grill.

Trace out the path from that register back to the main duct or
furnace. *First, make sure that nothing has come disconnected. *It's
common for taped joints to come apart and either leak badly or fall
apart completely.

As others have pointed out, it's possible you will find a flap in a
duct that controls the amount of air going to that register. *If so,
if it's not fully open you can adjust it.

It's also possible that this particular run is farthest away from the
blower, is long, more turns, etc. * For that, there are a couple of
possible fixes. * One is the type of add-on blower that just sits on
top of the register and gets plugged into a wall outlet. *It senses
when the system is on and turns itself on, pulling air out of the
register.

The other is an auxilliary blower that gets inserted into the duct
section going to that register or perhaps a couple of registers on the
same section that need more volume. * The blower is powered off of the
furnace blower or with a sail type switch in the duct. *I installed
one of those and it made a significant difference in airflow in the
upstairs bedrooms farthest from the furnace.

I would use the auxillary blower as a last resort. I have two vents
with very long runs. It made it difficult to keep our bonus room
comfortable. I think it's a common problem with bonus rooms since
they are often far from the air handler. I replaced the 6" flex with
8" flex and that solved the problem.