HVAC Tips: 6 Possible Reasons for Low Airflow Problems

Coming home to expectations of cool house temperatures in summer of warm and toasty temperatures in the winter is every HVAC owner’s expectation. However, when you turn on your air conditioner to cool your house and do not get the warm air or turning on the heat and not achieving the desired temperatures in winter, your HVAC may not be working correctly. Your HVAC relies on proper airflow to achieve efficient operation and energy usage. It’s important to keep your system maintained, and cleaned regularly by a Portland duct cleaning company.

Airflow problem can cause different conditions in your home, and you may have noticed a few such as:

• Hot and cold spots all over your home

• Weak or no airflow coming through your vents

• Warm air instead of cool air coming from the Air Conditioner

• Pressure imbalance, whistling sounds, and drafty areas

Taking note of airflow problems and fixing the fast can prevent the total failure of your systems. Here are possible reasons for low airflow problems.

1. Clogged Air Filters

The most common and persistent cause of low airflow in the HVAC is clogged filters. As your HVAC works to keep the air in your home clean, the filters do the work of gathering dust, debris, and biological contaminants in the air. After a while, these particles end up blocking the air filters, and you end up with unevenly distributed air and stuffy areas in your home. HVAC experts from Chicago HVAC recommend that you check and replace your air filters regularly, at least every 30-90 days.

2. Obstructed Condenser Unit

Your outdoor units are most prone to blockage from debris that collects inside and around it. Even condenser units located in an enclosed mechanical room can have furniture, clutter, and other storage items that prevent proper airflow. Blocked condensers will not effectively release heat from your home; the unit can potentially overheat and ultimately damage.

You can clear away leaves, branches, and any debris around the condenser unit. If debris has penetrated the unit, turn the power off before cleaning the inside of the unit. Clear away any clutter that could obstruct airflow in and out of the condenser unit if it is located inside a mechanical room.

3. Blocked Air Vents

Your heating system’s air vents and returns are strategically placed to provide proper airflow. However, furniture, drapes, and any clutter can easily block your ducts if you miss their positions. As a result, you will be experiencing heat even when you turn your thermostat low.

Check if your furniture and drapes are blocking the air vents and move them before the AC overheats. If the air vents seem damaged, consider buying and installing a replacement.

4. Damaged Ductwork

Unless you are using a ductless system, your home’s ductwork is the mode of transportation for air into each area of your home. A leaky or obstructed ductwork could cause low airflow in your house. If you have not inspected your ductwork in a while, it may have developed cracks, dents, and loose seams, causing air to escape. Also, old ductwork is prone to rust and fissures.

It is possible to check your ductwork for leakages through the exposed areas in the attic and basement. Specific blockages caused by dust, rodents, and insects will need an expert inspection to detect and clear away. You will need to schedule a maintenance check with an HVAC technician for inspection and determine possible repairs to solve the low airflow issue.

5. Low Refrigerant Levels

The low refrigerant level is a common problem, especially with old HVAC systems that are not well maintained. All HVAC’s used refrigerant to cool the air. Refrigerant leakage will cause airflow issues, and you will see this with low cooling. You will also notice warm instead of cold air coming out of your vents when you intend to cool the air.

Sometimes the assumption is that the refrigerant levels have depleted, and addition is required. But, note that this will not solve the problem if the cause is leakage. Scheduling a visit with an HVAC technician will enable them to check the leakage, repair it, and ensure your system’s airflow is back to proper flow.

6. Improper sized AC Unit

Believe it or not, the size of your SC Unit can determine the sufficient flow of air in your homes. In the past, the misinformation that bigger units are better. If your unit to big for the space it is supposed to heat or cool, it will run inefficiently. Airflow will be low because the unit will keep turning or and off frequently. If your unit is too small for your space, it will also have to run longer to heat or cool your home.

The only way to fix this is to have an HVAC technician do a load calculation of your home, considering the square footage, windows, and factors that can affect the house’s heating and cooling. This calculation will enable you to pick the AC Unit’s right size to suit your home’s heating and cooling needs.


Managing common airflow issues in your HVAC is easy if you know what to look for and fix the problems as soon as possible. You can also seek expert help from HVAC technicians if you are not sure where the issue is, and they will perform maintenance checks to prevent total system failure.

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