What should I check if the vents in rooms don't blow equally?

[Steve]

I have central heat and air. In the rooms on the north end of my house, negligible air comes out of the vents. As a result, they're too cold in the winter and too hot in the summer. What should I check to try and figure out the problem? Is it likely to be something I can fix myself, or do I need to get an HVAC contractor out to investigate and do repairs?

 

[highhosilvam]

DEPENDS WHO LAID OUT THE DUCT TUBING FROM THE HEATER A/C UNIT THE DUCT FARTHEST AWAY WILL HAVE LESS POWER REMEMBER 1 UNIT TON COOLS ABOUT 500 SG FT IF YOU HAVE A 3 TON UNIT 1500 SG FT.......CHECK DUCT THEM SELVES FOR LEAKS AND RETAPE IF DUCTS ARE SQUASHED OR FLATTEN CHANGE THEM CHECK ALL FILTER AND SCREENS

 

[john]

its most likely an air flow issue, due to the duct design , sometimes this can be assisted by
having an air balancing done, other times its the poor design of the duct work and a contractor
needs to decide what can be done.
john, ajax of oakland heating and cooling.