Home Ventilating Tips
by Building Inspector and Indoor Air Specialist, Dan Schilling
© Copyright 2002 Residential Inspections LLC, All Rights Reserved
Understanding Your Vents
Approximately half of your air registers blow heated or cooled air "out" and the other half draw air "in" to be reheated or re-cooled. The registers that blow air out are usually located on the outside or exterior walls of your home and are often located under windows. The registers that draw air back in, are usually located on the inside or interior house walls. So remember, in most homes, air comes out the outside wall registers and goes in the inside wall registers.
High Vents above Low Vents
If you air return vents on the interior walls of your home that are located one above the other, you can benefit if you know how to properly adjust the air return registers. There is usually a damper lever on each of the lower registers on these interior walls, but not on the top. Here is how you can adjust the levers on these registers to your best advantage:
When Heating The levers on the bottom registers should be in the position in which the bottom vent is fully open. By default, the cold air down at the floor level will be drawn into the bottom vent and will be returned to the system to be reheated.
When Cooling The levers on the bottom registers should be in the position in which the bottom vent is fully closed. By default, the hot air up at the ceiling level will be drawn into the top vent and will be returned to the system to be re-cooled.
Heating or Cooling Multilevel Homes
If you have a home with more than one level, balanced room temperatures can sometimes become difficult to maintain. This is largely due to the rising and falling of hot and cold air. Here is how you can adjust the registers in your home to your advantage:
When Heating First floor vents located on the outside walls should be full open and the second floor vents should be slightly restricted. This will promote more warm air distribution on the first floor which will naturally and gradually rise to the second floor between heating cycles.
When Cooling First floor vents located on the outside walls should be slightly restricted and the second floor vents should be full open. This will promote more cool air distribution on the second floor which will naturally and gradually fall to the first floor between cooling cycles.
NOTE: Performing adjustments as outlined above will help to circulate the air and maintain more even air temperatures throughout the rooms of your house. Minor deviations may be made in the adjustments if you have a room that is too warm or cold. Remember, if you restrict the air from one vent, you will be forcing a greater amount of air to the other vents. If you have a room that is excessively hot or cold, you may need to have the internal duct dampers adjusted. These dampers are usually hidden inside the air ducts in the basement or crawl space area but will have adjustment controls outside of the ducts.
CAUTIONS: Many doctors recommend filters that can be used directly on air registers in rooms, or magnets to close off air vents in rooms. Allergy supply companies are eager to sell these items. On the surface these ideas seem good, but in reality, they can reduce heating and cooling efficiency and have the potential of damaging your heating and air conditioning system by over restricting the air flow. These filters and magnets should never be used. A good quality furnace filter is a better choice. Also, you should have your heating and cooling equipment inspected annually for safety and efficiency.
with those you care about.