Air flow not even out of the HVAC vents

[Zack1978]

Hi everyone,
This weekend I spent a few days at our shore home. The forced hot air heat is cranking since it is cold here in NJ. What I noticed on Friday night was I was cold in bed....but the heat was on 70. In the morning I checked the vents and I noticed that the air volume out of the vent in my room was very little. In the other two bedrooms, one room is like mine, and the other room is like a hurricane blowing out of the vent. The bathroom vent also is blowing very hard.
The house has two separate furnaces, one is dedicated to the first floor, and the second furnace is for the second and third floors.
The furnace that is the issue is the second floor unit. On the second floor there is a vent in each of the three bedrooms and one in the bathroom. On the third floor, the air flow is ok, but certainly not like the one bedroom and bathroom on the second floor.
Any ides why the air flow is not even in the rooms? Is there anything that I can check?
Also in the bedrooms there is a second vent in each room that appears to be an air intake? Is that the case? If it is an air intake, is that air filtered in some way?
The only thing that I know that has been an issue (until yesterday) is that there was never a filter in the furnace on the second floor since the house was built in 2005. The builder never put a filter in, and I had no idea where the filter went on that unit. On the first floor there was always a filter that I changed often.

Thank you,
Zack

 

[fliphkd778]

Sounds a lot like what is known in the HVAC industry as a test and balance. Not so much for residential homes, but large buildings have each grill adjusted to provide the designed amount of airflow.

First thing to check is if someone has adjusted the anemic register/grill to a closed position. If so, open it up until you feel adequate flow.

If the low-flow vent is not closed, try closing down those that a blowing hard down a bit. This will force more air into the low flowing rooms.

 

[PAToyota]

One change to the above - are there dampers in the ductwork? Not just the registers - which should be obvious if they are closed.

I have dampers in the various duct runs in the basement and adjust the flow between winter and summer in my house. In the winter I typically want more airflow to the bedrooms and bathrooms for it to be a bit warmer where you are partially dressed. The living spaces can be a bit cooler. In the summer, the back of the house gets the full afternoon sun, so it requires more air conditioning to stay cool.

 

[AJP]

Had the same problem ... 4bdrm home .. 3 bedrooms are fine. Livingroom, family room, kitchen are fine, basement "ok" but the 4th bdrm was/is cold.... been adjusting vents and dampers for 10 years I think ... now I just put a extra blanket on the bed!

 

[itbrokeagain]

Vent pulled apart somewhere. I would disassemble that furnace and clean the blower cage, ac coil and heat exchanger ASAP if I were you

 

[wxm]

Just saw this now. Hope you have resolved the problem. I don't know anything about the HVAC, but this happened to me. The newer HVAC system these days all have the auto-shut control if it senses not air coming in from the intake. Given the cold and moisture air out side, it is quite common for intake pipe to freeze up and block the air from coming into the system... If it is your case, use a wood stick clear out the ice in the intake pipe.