There are several elements that influence airflow in your ductwork, but the bigger question is why does it matter?
When addressing airflow, we look at five key factors:
1. Dimensions & length of your air ducts
The more limited your airflow, the smaller your air ducts. Simply said, compact areas allow for less space for air to circulate freely and effectively. Small air ducts are commonly seen in many older homes since air ducts were initially built to transmit heat. The less airflow pressure present, the longer the ducting run (or length of the ductwork). HVAC contractors frequently shorten ductwork to boost pressure; however, shrinking ductwork reduces the ductwork’s size, resulting in a loss in air volume.
2. The dimensions of your a/c coils
Backpressure is created by A/C coils. When we drive airflow through small, narrow places, we produce backpressure. As A/C coils grow more efficient at cooling, the space between them becomes tighter and narrower, resulting in an increase in backpressure. Furthermore, small, confined areas provide an ideal habitat for dust, grime, and debris to accumulate at a rapid rate. Clogged a/c coils add to the reduction in space, resulting in higher backpressure or lower airflow.
3. Type of ductwork
- Externally lined sheet metal ducting is smooth and provides for good airflow.
- The roughness of sheet metal internally lined fiberglass ducting is harsh, preventing air from flowing easily. Because of the rough texture, dust and debris accumulate at a quicker rate, further restricting airflow.
- Flexible ductwork does not provide as effective airflow as sheet metal ducting and is sometimes misapplied, for example, for lengthy lines in a home. Because of its flexibility, this sort of ductwork frequently becomes condensed or “squished” between a home’s rafters and floors, resulting in reduced airflow.
4. Relocating to a new house
Things evolve and change with age, and your house is no exception. As your home settles, ductwork of any sort becomes compacted over time, limiting ventilation.
5. Clogged air ducts
When particles from our home environment accumulate in our ductwork, we have dirty air ducts. Dust, filth, debris, pet dander, pollen, mold, dust mites, and other particles that accumulate in our ductwork reduce volume and size, resulting in lower pressure and airflow.
So, what is the issue with limited airflow? Because of the restricted airflow, your home will take longer to heat and/or cool. This raises your electric, gas, or oil cost and forces your heating/cooling system to run at longer intervals. Running your system at lengthier intervals puts wear and tear on it and shortens its life.