Your heating system relies on efficient airflow to keep the house heated at all times. The air needs to flow to and from the heating system without obstructions. Below are some of the restrictions or obstructions that can interfere with the airflow.
Objects in the Air Duct
Air ducts supply air to different rooms and also return air to the furnace for reheating. The air ducts are designed (size-wise) depending on the amount of heating needed for different rooms. Therefore, if something is obstructing the ducts, it reduces the effective volume of the ducts, and hence the volume of circulating air. Frequent culprits include objects sucked into the air ducts such as loose parts of the heating system, like air filters, and dead animals.
A Clogged Air Filter
Since the air filter cleans the air getting into the furnace, the debris clog will lead to inadequate air flowing through into the furnace. The dirt and debris that the filter traps as it cleans the air will eventually clog it. That is why regular filter replacement is necessary.
The furnace blower is equipped with a fan that is responsible for getting the air moving. Dirt accumulation on the fan blades, which are usually cupped, changes the aerodynamics of the fan blades. The fan will still spin just fine, but it will be moving less air than it does when it is cleaning.
A typical heating system is equipped with several dampers that perform various purposes. For example, the fire damper prevents the spread of fire into the ductwork. The zone dampers control the volume of air passing into specific parts of the house. Unfortunately, the dampers sometimes get stuck in positions that prevent efficient airflow.
It is also possible for an air duct to collapse and restrict airflow due to the reduced internal diameter. Air ducts can be made from different materials, such as aluminum, fabric, PVC, and fiberglass, among others. Some of these materials are more susceptible to collapse than others.
Lastly, clogged resisters can also restrict airflow within the house. The registers are the openings that deliver air into different parts of the house or allow stale air to get into the ductwork for return flow to the furnace. Household objects, such as furniture, are some of the common causes of obstructions in these areas.
Your house may be uncomfortable if you are dealing with airflow obstructions. Contact a heating repair service to diagnose and get rid of the obstructions.