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  • Return Air Diffuser
  • Return Air Diffuser

Return Air Diffuser

  • Low Noise Level
  • Easy mounting procedure
  • Various designs and materials for different applications

Biyang Return Air Grille, also named Ceiling Return Air Diffuser, Return Diffuser, or Return Air Register, is made out of different materials, such as extruded aluminum sections, steel bars, plastic injections or solid wood.  Our products vary in different shapes, such as Round Diffuser, Square Ceiling Diffuser, Linear Diffuser, and so on.

The Return Air Grille allows air to get back to the heating or cooling system, or ventilation ductwork.  Biyang Return Air Grille can have a good connection to the return air ductwork and can be concealed suitably in a home or a building which works as a channel for pumping air out of the room.

As one of the leading supplier for Air Diffuser, Biyang products cover all types of Return Air Diffusers.  Aluminum extruded Return Air Grille is the most common product.  For different demands, Biyang provides extruded materials in 0.8mm, 1.0mm, and 1.2mm.

Biyang common coating is a cheap but good option to be used for normal interior situations.  Biyang highly resistant powder coating can be applied for a tough environment with colors made based on RAL color standard such as RAL9010 and RAL9016.  Air flow directions can be selected and made based on different designs.

Biyang Plastic Return Air Grille or Plastic Air Registers also vary in different shapes.  You can always select the right shape for your own project.  With existing injection molds, these are the good and economical choice for clean air ventilation.

Biyang Stainless Steel Return Air Grille or Stainless Steel Return Grilles are more expensive than other materials, but they can be used for structure supporting in the floor and bad environment.  Biyang offers different sizes for your selection and we can also make them based on your required size and structure.

Biyang Wood Air Grille can work as the Decorative Return Air Grille and is a good option for home overall matching.  This can be totally custom to your demand, with different paint finishes wood finishes or stain finish.

Biyang Return Air Grille has a variety of designs.  Please contact us for details.

ProductReturn Air Diffuser
MaterialAluminum, steel, plastic, wooden
ColorWhite power coated RAL9010/9016

paint finishes, wood finishes, stain finish

SizeOn request

Return Air Diffuser: The Ultimate FAQ Guide

If you’re looking for more information about the return air diffuser, then read this guide.

You will learn every aspect about return air diffuser systems.

Let’s get started:

What is Return Air Diffuser?

It refers to a type of vent in the HVAC component, engineered to discharge air in a particular direction, specific pattern, or spreading pattern.

It primarily directs air in numerous directions other than merely up and down depending on the particular type of diffuser it is.

In essence, the design construction for this component might include multiple air patterns.

It is also available in a number of shapes, and in most instances, it is installed in ceilings and also tend to have somewhat horizontal flow.

Return air diffuser

Return air diffuser

What is the Function of Return Air Diffuser?

The return air diffuser is an indispensable component in the general function of the HVAC system.

It plays critical roles, thus making it a necessary tool herein.

The primary function of a return air diffuser is to extract air from a specific room and recycle it through the HVAC system.

This consequently leads to enhanced conditioning of the recycled air within the system by cooling and heating hence increasing airflow efficiency within the room.

The second function of this component is to help in reducing the overall velocity of the air, which flows into the system as it increases its pressure.

Of course, this is fundamental since it enhances the productivity of the entire system.

Thirdly, the return air diffuser is also integral in distribution of air along various duct branches evenly.

In an ideal situation, consistent air distribution in any HVAC system is what makes it possible for you to stay within the space comfortably.

And lastly, this component also assists in reducing noise level, often occasioned by the fan.

If the HVAC system is installed correctly, the return air diffuser will certainly, help in suppressing the noise, which is often familiar with the running fans.

How does Return Air Diffuser compare with Register?

Ceiling register

Ceiling register

Essentially, a register refers to a grille, which has moving parts and can open, close as well as direct airflow in the HVAC system.

It primarily consists of fins, which are essential in channeling airflow towards a particular room.

Register controls the overall direction of airflow.

The heat registers are also adjustable and can also be opened or closed to allow for flow of air.

It consists of either standard or customized dampers or louver options.

On the other hand, return air diffuser does not have any damper since they need to permit free airflow into the vent.

It is comparatively superior to heat register in terms of efficiency and overall functional performance.

Return air diffuser

 Return air diffuser

What are the Common Types of Return Air Diffusers?

There are several types of return air diffusers in the market varying from one industry to another but play a similar function.

Even so, they come in different designs, which is also dependent on the supplier.

Some of the common ones you are likely to come across include the following;

Linear slot diffusers – They are the type of diffusers engineered to combine technical performance with aesthetics.

Typically, you can always mount this return air flow design in a false ceiling, or better still suspend it from the actual ceiling.

Louver bladed diffusers – They refer to the designs of return air diffusers, which supply air at the ceiling level.

They are available in either round or square shape but capable of deflecting in more than two directions, depending on where it is located.

Straight bladed diffusers – They are more or less similar to louver bladed diffusers only that some of the types of this design come with adjustable blades.

Perforated plate diffusers – These are the types of return air diffusers commonly used in manufacturing and processing plants.

They allow air to flow to all the directions hence enhancing efficiency in replacing contaminated air with fresh air from the supply.

Induction diffusers – They are the design of return air diffusers commonly used in office spaces hence also referred to as office type diffusers.

They are engineered to direct airflow into various directions within the office space.

Swirl diffusers – They refer to the design of return air diffusers, which rotate during fresh air supply hence allowing the distribution of cool air throughout the entire space.

What Parameters Determine Sizing of Supply Air Diffuser?

When sizing the return air supply diffuser, it is always important to figure out the critical aspects, which propel attaining desired results.

Some of the common parameters to look into when sizing this component include the following;

  • Height of ceiling
  • The general design of the space
  • The dimension of the area in regards to width and length
  • Cooling/heating area

It is also fundamental to understand that determining sizing of return air supply air diffusers entails a number of factors.

Some of these elements include the following;

  • Finding out the size and layout of the ductwork system.
  • Figuring out the heat load of your building. In essence, if the building contains several rooms, it would be indispensable to find out possible heat loss in every room. It is what, in the long run, enables you to the general heat load of the building.
  • The need to choose the most suitable return air supply diffuser for the ductwork system.

In general, it is always ideal to ensure you factor in all these parameters when sizing the supply air diffuser.

It helps in attaining and enhancing efficiency as far as air extraction and recycling in a particular space is concerned.

How does Return Air Diffuser and Nozzle compare in HVAC System?

Jet nozzle diffuser

Jet nozzle diffuser

In HVAC system, the purpose of a nozzle diffuser is to enhance the velocity of air as the pressure decreases.

Nozzles have different cross-sectional areas depending on the design of the component, as well as the volume of pressure it is projected to handle.

On the other hand, the function of return air diffusers in the HVAC system is to suppress the velocity of air as the pressure increases.

The essence of reduction in this velocity is, of course, to improve the proper mixture with the surrounding air.

What are the Benefits of Return Air Diffuser?

This component exhibits quite a number of advantages in the overall functioning of the HVAC system.

Some of the reasons, which make investing in this equipment a worthy deal include the following;

  • It ensures proper ventilation within a room or a specific space.

This, of course, is essential, and it happens by regulating the volume of air, which flows into the room as the pressure of the airflow increases.

Ultimately, this creates a serene environment hence enhancing the general experience in staying within the confines of the room.

  • It distributes airflow evenly in the desired directions.

The significance of this is it makes it possible for you to attain a proportional cooling effect within your space and to eliminate stuffiness.

  • It helps in cutting costs related to energy consumption since it tends to utilize the available air within the space.

This happens by extraction and recycling of the air inside the particular room.

  • It enhances the general aesthetics of the space in addition to the technical performance it offers.

This is important since it helps to create a visually appealing surrounding, especially when you match the color with other components of the room.

  • It is relatively easy to mount and maintain.

You do not necessarily require the assistance of a professional as long as you have the basic knowledge of how to go about it.

Moreover, most suppliers usually enclose a user manual, which is essential in guiding you on how to handle, install, and maintain the unit accordingly.

  • It is highly versatile, a clear indication you can use it in different applications across various industrial, residential, and commercial settings.
  • You can always get your ideal return air diffuser by making an order for customized designs.

This is beneficial since you’re certain of getting the specific type, which fits your requirements.

  • In addition to the extraction and recycling of air, the return air diffuser also plays a critical role in noise reduction.

It suppresses noise pollution within the specific setting hence creating a more serene environment.

Can you get a Replacement for Return Air Diffuser?

Absolutely correct! Several dealers can provide the replacements for this component.

However, it is always vital to confirm and establish the particular replacement is compatible with other aspects of the HVAC system.

What Factors do you Consider when Looking for Ideal Material for Return Air Diffuser?

Back of return air diffuser

Back of return air diffuser

You need to consider several elements when it comes to choosing the material for a return air diffuser.

It is what ultimately makes it possible for you to attain the desired results.

Typically, some of these factors include the following;

Flexibility – A suitable return air diffuser material must be flexible.

And at the same time, it should also exhibit incredible strength to withstand the dynamic pressure and volume typical with an HVAC system.

Durable – The material should also portray a number of resilient features to wide-ranging elements.

The essence of this is to enable you to attain the best results in regards to service from this component.

Insulation – If possible, always go for a material with proper insulation. This aspect plays an integral role in ensuring the material functions properly and effectively.

High resistance – It would also be vital to go for a return air diffuser material, which has incredible resistance to various elements.

Essentially, this type of material should be able to withstand different environmental, mechanical, and chemical elements.

It is a sure way of guaranteeing quality air, high efficiency as well as durability.

What is the difference between Return Air Diffuser and Exhaust Air Diffuser?

Absolutely correct!

These two elements tend to differ in some ways, which include the following;

Direction of air flow – It is arguably the biggest difference between these two elements. Fundamentally, in a return air diffuser, the air flows back into the ductwork system.

In exhaust air diffuser, the air flows out of the ductwork system.

Vent size – On many occasions, you’ll realize the size of the vent in return air diffusers tends to be relatively larger than those in the exhaust air diffuser.

The essence, in this case, is because an ordinary HVAC system has several exhaust air diffusers than return air diffusers.

Filters – Return air diffuser has several filters behind it.

Of course, this is essential since it helps to prevent dirt, dust, and other contaminants from attacking and hurting the HVAC system.

The filters tend to contain all the contaminants and before getting into HVAC’s air handler, which could result in damage.

Exhaust air filter, on the other hand, only has a few filters for filtering air for quality purposes.

Where is the Suitable Place to Install Return Air Diffuser?

Ideally, return air diffuser is a relatively versatile component.

It thus means you can mount in various locations within a building and still attain the best results.

Some of the common and suitable spots to mount this component include the following;

  • Ceiling
  • Wall
  • Floor

The precise location for installing this component is also dependent on several factors.

For instance, the general design of the room dictates the best place to install this device.

Also, the activities taking place within the room is another critical element, which determines location suitability for mounting this component.

And finally, the general design or type of the return air diffuser also defines the best place to fix it.

What is the Suitable CFM in Return Air Diffuser?

The ideal and recommended Cubic Feet per Minute in a diffuser in a standard return air diffuser is 50 per linear foot.

Is there difference between Return Air Diffuser and Grille?


Return air grille

Yes, these are two different elements of a HVAC system.

Grille is primarily a vent cover through which air circulates into or out of a particular space and back to the central cooling or heating unit.

It does not have a damper for controlling air flow, and this allows air to flow freely.

A grille essentially extracts and supplies air vertically without deflecting it.

It is also fixed permanently and mostly found in residential walls and ceiling surfaces.

On the other hand, the return air diffuser is somewhat an advanced grille located at the ceiling or hallway.

The essence of return air diffuser is to extract and recycle air from a room through the system, respectively.

It contains a cover, which attaches to a filter frame assembly.

How do you Choose Return Air Diffuser?

If you are a first-timer, you have to be meticulous when it comes to selecting and purchasing this component.

It is ideal to look into several factors as a way of attaining the best results regarding this equipment.

Some of these elements include the following;

Mounting location – It is always important to consider the specific use of the return air diffuser before purchasing one.

And this implies the particular area where you’ll fix the device.

It could be a factory, office set up, residential home, or hallways, among others.

All these settings require different types and designs of return air diffusers.

Material –Material plays a significant role because it determines several elements revolving around the durability, functionality, and efficiency, among others.

Air flow – It is the movement of air, which is directly related to composition, altitude, and temperature.

Air throw– It refers to the measurement of how appropriate shifts from the diffuser to the rest of the space it is cooling.

Noise criteria – An ideal return air diffuser should be incredibly silent irrespective of its CFM/L/s or any other related factor.

Ideally, it should help in diffusing any form of sound produced by the fan.

Terminal velocity – It refers to the optimum speed a free-falling object attains when the resistance of the medium resists it from further acceleration

Maintenance cost–A suitable return air diffuser should be cost-effective when it comes to repairing, maintenance as well as replacement.

Brand – It is also necessary to go for a reputable and reliable brand, which, of course, is tried and tested in various issues surrounding HVAC systems.

Is there Shape Limitation for Return Air Diffuser Designs?

Not at all! If anything, return air diffusers come in a wide range of shapes depending on the preference of the customer.

In many instances, customers often go for custom-made designs since they have varying requirements as far as the design specifications are concerned.

Some of the common designs of this component in reference to shapes include;

  • Square ceiling return air diffuser
  • Round ceiling return air diffuser
  • Rectangular flush mount ceiling diffuser
  • Square perforated diffuser
  • Oval perforated diffuser
  • Risk resistant ceiling diffuser
  • Square flush mount ceiling diffuser

Ideally, the specific shape design of this component is also dependent on the particular supplier.

It is thus necessary to always ensure you inquire from the manufacture to determine their capacity to produce a specific customized design.

What is the cost of Return Air Diffuser?

Return air diffuser

Return air diffuser

Generally, the cost of this component is dependent on several factors.

In most instances, some of the fundamental elements, which determine the pricing model for this component include the following;

  • Design
  • Brand
  • Shipping
  • Size
  • Customization needs
  • Type of material

So, in essence, there is no definite price for purchasing this component.

All these and many more aspects are determinant factors of this device.

What is the Suitable Color for Return Air Diffuser?

The ideal color for this component is dependent on the customer’s preference.

Ideally, it is available in wide-ranging color shades, which all meet the different approved color standards.

This is essential since you’re certain the shed you select will fit into the specific application accordingly.

How do you Size Return Air Diffuser Duct?

It is a process, which requires meticulousness. The stages for attaining sizing of the component include the following;

  • Check at the rear side of the outside of your condenser to determine the actual size of the return air diffuser
  • Now determine whether you’ll be using a return air diffuser duct of a rectangular or round shape.
  • Then calculate the size of the return air diffuser duct using depending on the conditioner’s size as well as the type of duct you are using.
  • Find the square root of the total dimensions you calculated at step 3, and you’ll have the actual dimensions of your return air diffuser sized duct.

Can Return Air Diffuser Duct be Insulated?

Absolutely correct!

Insulating a return air diffuser is essential because it helps in enhancing its durability, efficiency as well as the functionality of this component.

Insulating this device is also necessary since it helps in preventing leakages and other possible longitudinal warps and defects.

What is the difference between Return and Supply Air Diffuser?

Supply air diffuser refers to the ducting in a HVAC system, which distributes air inside a particular area, building, or room.

It supplies warm air upon running the heater. On the other hand, a return air diffuser sucks or returns the air to the HVAC system.

Where can you Use Return Air Diffuser?

There are several areas or environments where you can easily use this component to regulate, extract, and recycle air flow.

Some of these areas include the following;

Classrooms – It is integral equipment in any classroom setting.

In essence, classes often contain a considerable number of students; thus, the need for ensuring the air within the space is sufficiently extracted and recycled.

Hotels – You can as well find this component in various eateries, restaurants, and related spaces.

Such premises are often public hence tend to hold a number of people at any given time, thus the essence for having a return air diffuser.

Offices – You can also use this component in various office set up, whether open or closed.

It generally helps in regulating the air around hence creating a comfortable and serene office environment.

Shopping malls – Return air diffusers are also commonly used in a wide range of shopping malls.

It is essential in this setting due to the high traffic of people it experiences at any specific time.

What Quality Standards does Return Air Diffuser conform to?

Return air diffuser conforms to numerous quality standards internationally recognized.

These standards are essential since they enhance consistent production of the same, which meet the required customer and legal needs.

Some of the typical standards this component conform to include the following;

  • ISO 9001
  • CE
  • UL
  • ASTM
  • SGS
  • RAL9010

At Biyang, we design and manufacture high quality and reliable return air diffuser system.

Whether you want standard or custom options, we offer a perfect solution that conforms to the international and local standards.

Contact us today for the best prices on return air diffuser systems.

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