Damper selection can be tricky. It may seem like each damper type is designed for a specific task, but sometimes multiple damper types can fit the same application. How do you tell which one works best?

At AWV, we write blogs to help you understand your options. We want to help you make informed decisions when designing your HVAC system. For this article, we are going to test your understanding. We will list three applications that require a damper. Then, we will list two possible options for each application.

You choose the damper type you think will fulfill the requirement. At the end of the article, we will display our answers and explain why we chose each damper type. Remember to consider the details of application when you make your decision.

Application 1 – Cellphone Repair Shop

You are tasked with designing an HVAC system that will provide air conditioning to a cellphone repair shop. The shop will have a store front area, where customers can present their phones for repair or shop for accessories.

There will also be a repair area where store employees will conduct repairs on the customers’ phones. It will be the employees’ responsibility to keep this area clean. The store should be split into two different zones, so that customers and employees can maintain their own level of comfort.

Image of two dampers to be used in a cellphone repair shop

For this system, you will need:

Control dampers
Isolation dampers

Application 2 – An HVAC System with Excess Pressure

You are reviewing the designs of an HVAC system that will serve a large office building. The building will be several stories tall. Each floor will consist of open floors for cubicles, multiple standalone offices, and two meeting rooms. During your review, you discover a potential risk to the system.

You find several ducts that will potentially generate excess air pressure during heavy load. These ducts deliver airflow between floors. The amount of pressure involved could damage the surrounding HVAC equipment, if left unchecked.

Two dampers to be used to relieve excess air pressure

To alleviate the pressure in these areas, you will need:

Balancing dampers
Pressure relief dampers

Application 3 – Ventilation for a Transit Tunnel

There is a new transit tunnel in the works, and it needs an HVAC system up to the task. The tunnel will house a railway station that connects to the pre-existing subway network. The station will need airflow for commuters as they wait for their train. There will also be pathways connected to the new tunnel for railway technicians and staff to move between stations.

The HVAC system for this tunnel will be able to provide air to every connected space, but there is an additional consideration unique to this type of project: the piston effect.

Two dampers to be used in a transit tunnel

To direct airflow through this HVAC system, you will need:

Tunnel dampers
Isolation dampers

Below are our solutions to the applications listed above. Try to make your best guess on each application before you view the answers.

Application 1 Answer

For the cellphone repair shop, you will need control dampers to direct airflow.

Standard control dampers can establish the necessary zones for the storefront area and the repair area. You don’t need to isolate the repair area from the rest of the building. Employees will be working with exposed electronics to make repairs, but they won’t need the clean air environment of a laboratory.

Clean air requirements are reserved for facilities that design and manufacture individual chips, such as research labs. These facilities need dust-free airflow to manufacture these small, intricate parts.

Image of a control damper to be used in a cellphone repair shop

Repair shops may use vent hoods to conduct repairs on sensitive areas, but these units will be separate from the HVAC system. The building’s HVAC system can get by with standard control dampers for establishing zones.

Application 2 Answer

To alleviate the excess pressure in the affected ducts, you should use pressure relief dampers.

Pressure relief dampers will help relieve the pressure in these ducts. Each damper can be configured to open when pressure in the duct reaches a specific point. This ensures the pressure in the duct never reaches a critical point. Pressure relief dampers will close on their own when pressure in the duct returns to nominal. Balancing dampers aren’t designed for instant relief. They are designed to balance pressure between sections of ductwork.

Image of a pressure relief damper to be used to relieve excess air pressure

For example, consider a duct that runs along a hallway. This duct feeds air to several rooms along the hall. If you find a pressure issue in one room, you can use a balancing damper to adjust the pressure between the hallway and the room.

Use the pressure relief dampers in this scenario to keep your HVAC equipment safe.

Application 3 Answer

To direct airflow through the tunnel, use tunnel dampers.

Tunnel dampers are specifically designed for the intense airflow needed for tunnel structures. HVAC systems need to produce massive airflow to provide the necessary ventilation for these spaces. These dampers are built from heavy duty materials. Transit tunnels will need to deal with piston effect.

We discussed this effect in a previous blog. To summarize, high speed trains create a massive gust of wind when they pass through a tunnel. This gust can be particularly strong when the train reaches a stop, disrupting commuters while they wait for the train to arrive. Tunnel dampers alleviate this effect by opening and releasing the pressure before it reaches the stop.

Image of a tunnel damper to be used in a transit tunnel

Isolation dampers are also built from heavy materials, but they are designed for near zero leakage applications. Isolation dampers work best for environments that need clean air, like microchip manufacturing facilities or sensitive research labs.

How did you do? Did you choose the best dampers for each application? It’s important to understand the needs of each application when selecting the right dampers. You can review our blogs if you need a refresher. If you have a current project, and you need help, don’t hesitate to ask AWV. We have over 100 years in HVAC, helping customers find the best solutions for their systems.

Consider adding AWV dampers to your next project. We build every damper to meet your requirements. Browse our wide range of dampers today. When you’re ready, contact AWV online. We are ready to help you!

Which Works Best? - Damper Selection