Best Diffusers For Your HVAC Duct System

In the world of HVAC engineering and design, there are a myriad of materials, pieces and parts. In order to have a firm understanding of how HVAC systems work, it is vital to have a firm grasp on the individual parts that make a system whole.

While many HVAC designs contain a collection of these pieces, not all systems contain all the different pieces every time. Some parts are more appropriate for certain designs. One such part is the diffuser, which helps “diffuse” the air through your room.

The diffuser is a part that serves a vital function but also has decorative appeal since it’s the part that facing the room. There are many types and shapes of diffuser that lend themselves to different applications.

Quick Comparison Chart of the Best HVAC Diffusers

What to Look for in a Diffuser

A diffuser is most-often utilized in a system to create airflow throughout a space. Let’s discuss how to evaluate and apply the appropriate diffuser in a specific setting.

The selection of an air output is as important as any piece in the design of an HVAC system. If an inappropriate output is chosen, then the entirety of the system is impacted negatively. This would be a waste of the expense of the design, mechanical systems, control systems and the like|.

There are a couple of main factors to keep in mind when starting the selection process for an appropriate diffuser: performance and design. Performance impacts many aspects of the decision-making process. The appropriate diffuser will impact the maximum space, create maximum comfort while maintaining maximum efficiency. It will also be minimally noisy.

“Throw” and “drop” are major pieces of the performance consideration. The “throw” is the distance the air travels from the face of the diffuser. “Drop” is the distance of impact from the face of the diffuser downward into the space. Drop mostly impacts the comfort of the room. An inappropriate amount of drop will create the feeling of a draft in a particular space in the room. A proper diffuser will allow air to flow out and along the ceiling before falling into a space, creating an overall better and more consistent comfort level.

“Spread” also impacts the overall effect of an HVAC system. The spread is the horizontal impact of the air leaving the duct. The wider the spread, the lesser the drop. This can improve the comfort in a room. Overall, lower drop is better as it will eliminate a drafty environment and avoid hot and cool spots in the same room.

The last major consideration is the sound impact. Diffusers can range in sound levels and each room has an appropriate sound level depending on its use, space and design.

Of course we need to note that all these factors are impacted by the system itself and the airflow created by the system. A diffuser can help but is not a be-all and end-all solution. When deciding on a diffuser, consider all these elements and how they fit the design of the space they are being installed.

Review of the Best HVAC System Diffusers

There is great diversity amongst options when trying to select a diffuser. When looking at the myriad of choices, you must always consider the application being chosen for.

What is a Diffuser and How is it Different from a Grill or Register?

A diffuser is a common component in most HVAC systems. The main role a diffuser plays is spreading the air around a given space to increase the impact area of the air. A diffuser also allows air to be comfortably spread, as opposed to pouring directly out of a duct onto the space below it. The diffuser is beneficial for noise reduction, assuming the system is designed properly.

While a diffuser can come in many shapes (square, rectangle, linear or round), the most popular and recognizable style is the large round diffuser. A classic presentation is round ductwork in an open ceiling concept and circular (round) diffusers spaced appropriately along the duct. The diffuser, in this scenario, spreads air along the ceiling to enhance the cooling effect of the system.

In the majority of scenarios, a diffuser works on the air delivery side of the system. In a few cases, they may be used on the return side but most often a grill serves as the inlet.

Oftentimes, a novice may confuse the grill or register with a diffuser in an HVAC system. In the simplest terms, a grill is used to keep large objects from entering the HVAC systems both on the return and output side. Most often, a grill is used on the return side to protect the system from objects entering the intake. An air return is most recognizable by the large square or rectangular grill covering the duct. This air is then returned to the central system for reconditioning and cooling.

A register is a grill with a damper attached to it. As a grill is often used on the return side, it must be free of a damper to ensure the unrestricted flow of air back to the central system. A register is often used on central heat systems so the flow of air can be controlled via the damper.

A diffuser spreads air in a given space, a grill allows uninhibited flow of air and a register allows airflow restriction as the user sees fit. The diffuser proves unique as it can truly control the directionality and impact of an HVAC system. It is valuable in the spreading of cool, conditioned air through a given space.

Conclusion

The selection of a diffuser plays a major role in the success and efficiency of an HVAC system design. While most diffusers will do an adequate job, the most appropriate diffuser will allow for a highly-efficient, highly-effective system that will be pleasing to those involved with creating and benefiting from the system.

There are many, many diffusers that have a myriad of appropriate applications. It is important that any HVAC engineer realize the impact that the diffuser can “make or break” the unit. The selection of the appropriate diffuser could be considered the most important choice when designing an HVAC unit.