Air ducts: Know their importance in the SVAC - AJ´s AIR
Air ducts: Know their importance in the SVAC
February 28, 2021
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Air ducts importance in the HVAC

Air ducts importance in the HVAC

Air ducts are structural elements that allow air circulation in a controlled manner by means of an HVAC.

Likewise, the air ducts can also extract stale air from a room or introduce new air from the outside in order to regulate the temperature and clean the air in a closed space.

What are air ducts and how do they work?

It is important to note that air ducts are the elements of an air conditioning or air conditioning installation, through which we distribute the treated air between the air conditioning device and the conditioned spaces.

To achieve their objective, the air ducts must be dimensioned within the available space in order to adequately control speed, noise level, pressure drops, as well as heat losses or gains, in addition to avoiding leaks.

Types of air ducts

Flexible air ducts

The most widely used flexible air ducts in HVAC are made of two sheets of PVC or aluminum, with an intermediate insulation and a spiral steel wire armor to keep the part circular.

They are used as connecting sections from the main conduit to the terminals or outlets, with a maximum length that is recommended not to exceed 39.3 inches due to the possible loss of load or noise production.

Sheet Metal Air Ducts

These are air ducts made of different materials that adapt to any installation. They require external insulation to avoid temperature loss, isolate noise and protect the duct.

Glass wool air ducts:

They are rigid panels that make use of agglomerated glass wool. They are covered by an external aluminum layer that acts as vapor protection and makes the duct hermetic.

Air duct distribution parameters

Duct distribution systems are classified according to two parameters:


  • Low speed: With airspeeds between 157.48 and 393.70 inch / sec. The most common in air conditioning systems
  • High speed: With speeds of more than 393.70 up to 590.55 inch / sec. Used in the conditioning of industrial premises or large spaces, where the sound level is not critical.


They are classified according to the type of fan that fits in the system:

  • Low pressure: Up to 70 Pascals.
  • Medium pressure: From 70 to 3000 Pascals in most installations.
  • High pressure: More than 3000 Pascals.

Depending on their function, the ducts receive the same name as the air they carry.

Considerations when installing air conditioning ducts

Keep in mind that air ducts are the best option whenever we have to acclimatize more than one room. This is due to several reasons:

With air conductors, you only need to buy an air conditioner

The first thing that comes to mind is the financial savings of not having to buy more than one air conditioner and the fact that the ducts do not have an expiration date.

In addition, not only money is saved, but the time and space that the installation of more than one device would suppose us.

Savings in energy efficiency

No less important is the energy saving, since the greater energy efficiency derives from the fact of working with a single large capacity air conditioning unit instead of several lower power appliances.

This allows us to ‘zoning’ or the ability to regulate the temperature and air flow in each space, in addition to representing great savings at an economic level.

Aesthetics and decoration

Usually, we place the air conditioners outside and move the air through them from one room to another, through ducts that are placed in false ceilings, in this way, the air will reach the different rooms through a grid that reduces noise and controls airflow.

As you can see, air ducts are an excellent option for air conditioning distribution.

Always remember to perform air conditioning duct installations and leave air conditioning maintenance to refrigeration specialists. Contact us, our technicians will be happy to help you.