HVAC (heating, ventilation and air conditioning) baffles control the flow of hot or cold air throughout a structure's heating and cooling system. Baffles are designed to be adjustable, allowing greater air flow control. If the baffles are properly adjusted, the system will operate at a more efficient level. If the baffles are positioned incorrectly, it will take more time to heat or cool a room. The longer an HVAC system runs, the greater the energy cost. Use a few professional techniques to adjust the HVAC baffles, improving the efficiency of the structure's heating and cooling system.

HVAC baffles control the flow of air throughout the system.
The baffles are located near the HVAC unit.

Step 1

Locate the baffles. The baffles for most HVAC systems are located near the HVAC unit. In a residential structure, the unit would be located in the basement, or the garage if there is no basement. Look for a series of large galvanized steel tubes coming from the HVAC unit. Examine the sides of the tubing. There will be a threaded rod with a wing nut attached to it. At the end of the rod is a slot. A screwdriver is placed in the slot to adjust the baffle.

Use a spray lubricant to get into tight places.

Step 2

Lubricate the baffle. Place the spray lubricant's nozzle in the gap between the threaded rod and the metal duct. Spray the rod and the threaded opening. There is an identical rod on the other side of the duct. Spray that gap as well.

Use a screwdriver that fits tightly into the baffle's slot.

Step 3

Adjust the baffle. The screw slot in the threaded rod's head indicates the direction of the baffle. The baffle is a piece of metal slightly smaller than the diameter of the duct. The baffle controls how much air is pushed through the HVAC system. If the slot is parallel to the duct, the baffle is completely open. Place a standard screwdriver into the slot. Turn the threaded rod until it is parallel to the duct. The baffle is now set in the open position.

Open the vents all the way.

Step 4

Adjust the vent baffles. At the end of each duct is a room vent. The room vent can be opened or closed by adjusting a sliding switch on the side of the vent. Set the vent's baffles to the open position by sliding the switch and watching the vent baffles. When the vent baffles are parallel with the vent's casing, stop adjusting the switch.

Step 5

Test the HVAC system. Turn on the heating or cooling system at the thermostat. Allow at least 10 minutes for the system to fully engage. The HVAC system takes time to start circulating air throughout the structure. After 10 minutes, hold a piece of paper over the vents. The air pressure from the vents will cause the paper to flutter, indicating that air is successfully passing through the ducts. If the air is not flowing through the vent, check to see if there is a second baffle in the duct-work near the HVAC unit or if the air filters are clogged. The filters are located on the HVAC unit. Follow the same procedures for adjusting any additional baffles.