A consistent airflow is vital for the performance and energy efficiency of the HVAC system. If the airflow is impeded or inhibited, there can be a number of problems from a lack of treated air right up to overheating and equipment failures. If you’ve experienced hot or cold spots in your home or strange whistling noises, this may be caused by low air pressure. If you place your hand up to the vent when the HVAC system is running and there is a lack of air this is a sure sign that something is wrong. In this article, we will look at eight leading causes of HVAC system airflow issues.

1.  Blocked Air Vents and Registers

One of the leading causes of a decreased level of airflow through the vents is closed or blocked vents and registers. They should be open, clear and not blocked by drapes, wall hangings, high pieces of furniture and other obstructions. In a larger home or office, it can be hard to get people to agree on the thermostat settings. Some people may attempt to compensate by closing or blocking air vents and registers to alter the temperature in their office or room because they feel cold. A better way to handle this problem is with HVAC zoning which allows for more precise temperature control in different areas of the home or business.

2.  Clogged Air Filters

Many people believe that the primary function of an HVAC air filter is to improve the indoor air quality (IAQ). But, this is a misconception, some improvements to IAQ are made, and yet this is a secondary benefit. The true purpose of an air filter is to protect the sensitive components in the system from dust and dirt particles that can cause damage. When the air filters are clogged with debris, they prevent the easy passage of air that is essential for normal operations. The HVAC system may run harder to try and push air through the clogged air filter, which causes the equipment to overwork. When components are overworked in this way, they are more prone to failure. This can lead to an unexpected repair bill that can be easily avoided with a simple air filter change. As an added bonus, a clear air filter will make the HVAC system more efficient, and this will lower your energy bills. So, if you can’t remember when you last changed the air filter, do it now and follow the manufacturer’s recommendations for the frequency of future changes.

3.  A Condenser Unit Obstruction

This is a common problem, and like the air filter issue, it’s easy to fix yourself. Most conventional air conditioning systems have a condenser unit located outdoors or in a dedicated mechanical room. The outdoor units are more common in residential homes, and they are exposed to a wide variety of weather conditions. They are designed to operate in these conditions, but they are vulnerable to obstructions from leaves, twigs, litter, and other debris. Any debris that’s accumulated around the outdoor condenser unit should be removed to prevent overheating issues that can degrade performance and energy efficiency. Prevention is better than the cure; remove any items stored around the unit, cut back any plant growth in the area and keep it clean and tidy.

4.  Thermostat Problems

The thermostat is the brain of your entire HVAC system, and if it’s not functioning as intended, this will be reflected in the performance. A lack of HVAC airflow could be caused by a thermostat with a fault sensor unit or even a failing battery that needs to be replaced. If you have an older thermostat, it may be time to consider an upgrade to a programmable or smart unit.

5.  A Slow Blower Fan

The treated air is pushed through the air vents by a blower fan, and the airflow is decreased if this unit is not working at optimal efficiency. The blower unit can be coated with dirt and grime, which can degrade the performance. Another potential problem is a blower motor that’s beginning to fail, and a replacement may be required. If the fan itself is dirty, it’s easy to clean, and this can improve the airflow.

6.  Dirty Condenser Coils

The AC condenser coils are a vital part of the air conditioning system. They are designed to release the heat that has been collected from the interior spaces. The condenser is located outdoors, it’s exposed to the natural elements, and it can get dirty. When the condenser is dirty, it needs to work harder to cool the spaces, and this can lead to overheating problems. This indirectly causes airflow issues, and it’s advisable to get the coils clean once or twice per year to prevent these problems. Cleaning the condenser coils is included in a regularly scheduled maintenance visit.

7.  Leaky or Blocked Air Ducts

Any dust that gets past a clogged air filter will accumulate on the inner surfaces of the air ducts. When dust builds up, the capacity of the AC system is diminished because the ducts are narrowed, and they can clog easily. This is especially true if you live in an older building and there may be insects, birds, rodents, and other pests living in compromised air ducts. Another problem is cracks and leaks or gaps from improperly installed air ducts that release the treated air. The airflow will be redacted and can lead to a number of other problems. The best course of action is to schedule an inspection or air duct cleaning to fix the problem.

8.  Low Refrigerant

If an HVAC system is older or poorly maintained, it can be prone to refrigerant leaks which will indirectly lower the airflow and performance. The refrigerant must be kept under pressure to circulate through your home to collect and transport the heat outdoors. A slower refrigerant leak will lead to a gradual decline in cooling performance. It’s tempting to recharge or top off the refrigerant yourself, but this is a bad idea. There are very specific refrigerant grades, and they should not be mixed, or the performance is degraded. It’s also important to identify and fix any refrigerant leaks before more is added. Checking the refrigerant levels is an important part of regularly scheduled HVAC maintenance.

If you have air conditioning airflow problems, contact your local heating and cooling specialist today.