Replies

1. GBA Editor
   Martin Holladay|Oct 25, 2017 11:52am|#1

   Masb,
   Before we give you advice, we need to know what your complaint is.

   Complaint #1: "The temperature varies from room to room." This problem can be remedied by either installing zone valves, replacing baseboard units that aren't sized correctly with the right sized baseboard, or improving the air-sealing measures or the window performance in the cold rooms.

   Compalint #2: "The air feels stuffy." If this is the case, you might need a mechanical ventilation system. For more information, seeDesigning a Good Ventilation System.

2. Expert Member
   Dana Dorsett|Oct 25, 2017 03:21pm|#2

   Duty-cycling the air handler for the central AC would redistribute the air, but not the heat. If your central air system was designed with outdoor air ventilation intake & distribution it COULD be used for ventilation by duty-cycling it, but it's not very efficient, since most of the energy is spent just moving air around within the house, with only a small fraction of it being fresh air from the outside. If the AC system is not designed with ventilation air factored in, it's doing even less, but it might be doing some parasitic ventilation (at even worse efficiency):

   用管道输送交流不可避免地pressuriz空气处理程序e/depressurize rooms relative to one another, and some of the air movement that evens up the pressures uses "the great outdoors" as part of the return path, through all of the random air leaks in the house.

   The total volume of air moved by the air handler is also an order of magnitude larger than what would be needed for mere ventilation. The pressure differences induced even by unbalanced ventilation at appropriate ventilation volumes is tiny compared to those generated by ducted cooling & heating air handlers.