8 Common Causes of Low Airflow from a Home HVAC System

If certain rooms feel uncomfortable despite repeatedly adjusting the thermostat, try placing your hand over a few supply vents. Does the air seem to barely blow from the register? If so, your HVAC system is suffering from low airflow. Here are the eight most common reasons for this and how to fix each one.

1. Closed air vent: Before you panic, make sure the air vent you’re testing is open all the way. Adjusting the louvers may be all it takes to restore airflow. Check all the return and supply vents around the house to ensure they’re open and unblocked by furniture, curtains, or area rugs.
2. Dirty air filter: Airflow suffers as the filter becomes clogged with dust, hair, pet fur, textile fibers, and other airborne debris. To prevent this, change the filter every one to three months or as the manufacturer directs.
3. An excessively efficient air filter: The Minimum Efficiency Reporting Value (MERV) conveys a filter’s efficiency, with higher MERV ratings indicating a tighter material weave. If you want to install a filter above the MERV 7 to 12 range without overly restricting airflow, you’ll need an HVAC technician to boost the fan speed.
4. Crushed or disconnected ductwork: The further conditioned air must travel through ductwork, the more turbulence is created, and the less air reaches its intended destination. Add a partially crushed, bent, kinked, or disconnected air duct to the mix, and the airflow is sure to suffer even more. If this is the underlying cause, you need an HVAC technician to fix or replace the damaged ductwork.
5. Leaky air ducts: Most ducted HVAC systems have significant leaks, wasting conditioned air and reducing airflow from the register. Sealing your leaky ducts can improve airflow by up to 50 percent.
6. Poor ductwork design: This could include meandering ducts, oversized ductwork, or an insufficient number of return vents, all of which impair airflow. A ductwork redesign and installation is the only fix available.
7. Undersized HVAC system: Have you made additions to your home since installing your furnace and air conditioner? Perhaps your HVAC equipment has always been undersized. Either way, your system may have an inadequate blower that can’t produce the airflow required to keep your home comfortable. The only option is to replace your heating and cooling system with properly sized equipment.
8. Sluggish blower motor: If you haven’t maintained your HVAC system in years, the blower motor may be all gummed up. A thorough cleaning and oiling may restore proper function and airflow. Otherwise, you may need to replace the blower motor, an affordable repair to restore home comfort.

If you’re struggling with hot and cold spots, high humidity, or other problems caused by low airflow, turn to Parley’s PPM Plumbing, Heating & Cooling for the HVAC repair you need. We offer 24/7 emergency services for your convenience. To schedule a visit from our experienced team, please call 801-226-3033 if you live in Utah County, or reach us at 801-229-2665 if you’re a Salt Lake County resident. You can also contact us online with any questions you have.