May 28, 2019

How HVAC System Manages Airflow


Airflow is very important to your home HVAC system. Your HVAC System manages airflow in your home. The system takes in air, warms or cools it and then redistributes it around your home to maintain the desired temperature.

Of course, there is much more to it. As the air is brought into the system, it is filtered to remove contaminants and debris.

Residential HVAC systems require unobstructed airflow in order to operate properly.

Airflow Resistance

Resistance is caused when airflow is blocked or limited. The air is pulled into the system by a motor operating a fan which pulls the air in.

Dirty Air Filter

Most residential HVAC systems use a 1/3 to 1/4 horsepower motor to do this. This is sufficient to pull the air through the filters and into the system for cooling or heating. If there is any strong resistance, blockage or impediment to the air flow it can cause the motor to have to work much harder. A consistent strain on the motor can damage or weaken it’s function.

Sometimes there are purposeful obstructions such as dampers installed in the ductwork to limit airflow to particular areas at certain times. These do not interfere with normal functions of your HVAC system and allow control over zones in your home.

Obstructed HVAC

Airflow to outdoor units is also important since they can become hot and use the fans to cool the units. If the unit continually runs hot it can damage the system. It is important to keep any obstructions away from your outside HVAC units. There should be at least 24” clearance surrounding three sides and 6” to the building. There should be 36- 48” clear space over your units.

Obstructions include walls, shrubbery, tall grasses, fencing, etc. This is a general rule of thumb clearance requirement and may vary somewhat per the manufacturer’s instructions.

Air Intake

Clean air intake is important to the proper function and efficiency of every HVAC system. Your air filters are important to this function. Air filters require replacement every three months or every month is you have pets or high traffic. This ensures that contaminants are reduced or eliminated before being conditioned and recirculated into your home.

There are many different kinds of filters, some only remove larger particulates, others can remove fine particulates, microbes, mold spores and other debris. See our blog on Air Filters.

Reme- Halo

Air purifiers take it to another level by destroying most all contaminants, microbes, VOCs and odors. For more information visit our Reme-Halo blog.

Air Output

The air output should be cleaned and conditioned (either heated or cooled) air which is recirculated throughout your home. The volume of air circulated is dependent on the size system you have. If your air filters are dirty or clogged then debris and contaminants will enter your HVAC system and may cause buildup or damage. Furthermore, the contaminated air will be recirculated into your home which can cause many health concerns.

AC Maintenance

Regularly scheduled twice a year HVAC maintenance is important to ensure your system is operating properly. Air Doctor Heating and Air can provide you with service and maintenance. We also offer maintenance contracts which provides these services and also offers discounts.


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