In residential air distribution system, to balance the supply of conditioned air among the distribution system, a device called Volume Damper is installed, by using a simple nut and bolt, near the exit of the supply air from the air distribution system (duct system).
To be comfortable in a room the air distribution system must deliver the designed CFM as per Heat Loss / Heat Gain Analysis for that room.
To achieve these CFM, the position of the Damper needs to be adjusted and locked. To effectively lock the Conventional Volume Damper at the required position, the access to the wing nut is required. But unfortunately this wing nut gets covered under the dry wall. So, effective Air balancing cannot be achieved with the Conventional Volume Damper, which leads to hot and cold spots in the home.
Most of the home owner assumes the reason for these hot and cold spots, is undersized furnace or A/C and so he installs supplementary heating (i.e room heaters) or Cooling (i.e window A/C) devices, which increases the utility bill.
This lack of Air Balancing causes two types of energy wastage in home.
- Energy wastage, when Air Balancing is not done at all, meaning dampers are fully open and air flow is delivered to the supply registers as per the resistance faced by the conditioned air in reaching that register.
- Seasonal Energy wastage, which is associated when we do not move the damper from its summer position to winter position and vice versa.
Location of Volume Damper
Boot Assembly through which the conditioned air is delivered into the room.
Boot assembly parts, Boot, Volume Damper, Pipe
Damper is used to regulate the air supply into the room.
Short comings of Conventional Volume Damper
- As conventional volume damper cannot be locked at the desired position during air balancing hence designed air flow cannot be guaranteed.
- After construction wingnut is not accessible to lock the damper at required position.
- Hot and cold spots are caused due to poor air distribution in the home.
- Due to its poor design and vibrations in the duct work, it will become loose and will rattle.
- Utility bills are higher due to longer furnace / AC operation hours.
- Home owner cannot perform the seasonal air balancing.
- The lost balancing position during duct cleaning cannot be retrieved.
- The damper is made of very poor quality, sometimes break during air balancing.