I just bought my house and it stays rather cool. However I've found while painting that the flow of air through the house is limited. My vents are all on the base board/wall if you can imagine. Not sure if it matters, however some of these vents have no ventilation in them at all. In particular the bedrooms. Don't get me wrong it's cool temperature wise throughout the house naturally. I am generally concerned when it comes to winter. I would like to improve this, how can I?

I also noticed that in some spots the vents were actually blocked, could this be to improve the flow?

  • Some vents should be partially blocked. Your furnace/fan only puts out X cfm of air, and that needs to be divided up properly between all vents. By opening up a vent, that particular room can get more airflow, but at the expense of other rooms. If your house doesn't have enough airflow in any room, make sure the blower has enough power. Jul 29, 2015 at 18:53
  • air sealing the ducts you can access with a good quality duct mastic may help, as it will eliminate air leakage and have more air to be forced out the vents.
    – user20127
    Jul 29, 2015 at 20:57

1 Answer 1


For heating, the supply vents should be low on the walls, so that's a point in favor of winter performance.

You might be well served to have the system checked, possibly cleaned, and flow-balanced by a HVAC professional.

Note that a common misconception/error is that "opening up all vents to the maximum" is a good thing and reduces the workload of the fan - more air does move, but in point of fact, because more air is being moved, the fan is doing more work, and that takes more power - it is possible to overload the motor by "opening up" too many things fully (though this is usually controlled by less-accessible balancing dampers on the ducts, rather than louvers on the grilles in the rooms.)

The other major thing you can do before winter is to caulk, seal and insulate (or at least check the state of those things, and correct any deficiencies.)

  • Another issue I've found in the last few houses I've lived in is that the air returns end up being blocked by furniture and the like. It's great that the air handler is attempting to push out air, but if it can't be fed BACK to the air handler, the flow is greatly hindered. Jul 29, 2015 at 19:29

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