Best Concentric Vent Kit Guide: How to Find the Right One?

Adequately disposing of the different types of smokes of heating systems generate is crucial for the unit’s functioning and your safety. In this guide to the best concentric vent kits, we’ll show you how to use them to draw dangerous gases out of your home.

These kits are designed for high-efficiency furnaces and water heaters, and before you start searching for a concentric vent, you must first find out which model is compatible with your home’s heating system.

So, to make the search for a concentric vent kit easier, we’re going to take you through some of the best options you can find on the market. You should also go through our guide to furnace types to learn more about the central component of all home heating systems.

The 5 Best Concentric Vent Kits

Model Pipe diameter  height price range
DiversiTech CVENT-2 2 inches 34.75 inches $$
RHEEM SP20245 3 inches 42 inches $$$
AO Smith 9006328005 3 inches 40 inches $$$$
Dakota Sourcing 22152 2 inches 34 inches $$$
DiversiTech CVENT-4 4 inches 59 inches $$$$

What is a High-Efficiency Furnace?

To understand what a high-efficiency gas furnace is, you first need to understand the concept of Annual Fuel Utilization Efficiency or the AFUE. This rating shows the amount of heat a unit can generate from the fuel it uses.

In order to qualify a high-efficiency gas furnace, the unit must have an AFUE rating above 90%, which suggests it generates more heat than a conventional vent system can withstand.

Concentric vent pipes are made from PVC material that is not affected by exposure to hot gasses. Besides furnaces, concentric vent kits can dispose of the gases generated by residential water heaters. Read our guide to water heater systems if you’re unsure how these systems work.

The Contents of a Concentric Vent Kit?

Concentric Vent

All concentric vent kits contain the following components:

  • rain cap
  • 2 pipes with different diameters
  • Wye fitting

The wye fitting enables you to connect the gas furnace’s vent and combustion pipes, while the two-pipe system guides the gases outside of your home. The longer inner pipe that holds the rain cap that protects the system from moisture is located inside a shorter pipe attached to the wye fitting.

Unlike conventional vent systems that require you to drill a hole for both vent and combustion pipe, the concentric vent kits allow you to drill just one hole. Optionally, you can extend the length of a concentric vent by removing the wye fitting and attaching another pipe to the system.

It is worth adding that the diameters of these vent pipes vary from 2 to 5 inches, and you must make sure that the model you choose can be fitted onto your furnace or water heater. Check out our guide to the best fireplace systems for further information on how these systems work.

The Installation Process

Although they simplify the process of installing a vent system by reducing the number of holes you have to drill in a wall or roof to just one, concentric vent kits are still difficult to install.

Hence, you should hire a professional contractor to complete the installation for you, as failing to install this system properly can result in gas leakage.

The concentric systems can be installed either horizontally or vertically, so you don’t have to search for a specific model if you want to guide the furnace’s ventilation system through the roof.

It is worth pointing out that you cannot connect multiple furnaces to a single concentric vent, as each unit must have its ventilation system. Also, the manufacturers provide detailed steps for procedures that have to be completed before the installation process can begin.

Read our guide to the best induction furnaces if you’re in the process of setting up a metalworking workshop.

Adjusting the Length of the Pipes

Finding the kit that fits the distance between the furnace and the wall or a roof perfectly can be difficult, the most pipes are between 30 and 40 inches long. Fortunately, you can trim the pipes if they are too long, but you must shorten each pipe equally.

Cutting both pipes to the same length will affect the kit’s efficiency, and you’ll have to get another kit if you do so. However, extending the length of the pipes up to 60 inches is also a possibility, as you can insert an SDR-26 PVC pipe between the wye, fitting the kit’s wider pipe.

Adjusting the length of a concentric vent kit on your own isn’t advisable, and you should allow a professional installer to complete this task for you. Some models don’t have a fixed length, and their telescope design enables you to modify the pipe’s length without cutting it.

Read our guide to the best HVAC tools to find the tools that will enable you to shorten the pipes in the concentric vent kit.

Using the Concentric Vent Kits for Water Heaters

These kits are compatible with tankless and various other types of water heaters. Structurally, there is no difference between kits designed for furnaces and water tanks as both options allow air intake and exhaust gases to move through separate chambers.

Opting for a concentric vent kit enables you to direct exhaust gases from a gas water heater outside and guide the unit’s combustion air. Consequently, you won’t have to drill multiple holes to terminate gases, and you’ll be able to shorten the length of the water heater’s vent system.

Even though there’s no structural difference between concentric vent kits for furnaces and water heaters, you must check if the model you want to get can be used as a ventilation system for a water heater.

Read our guide to the best propane conversion kits if you want to change the type of fuel you’re using to power your furnace.

The Most Important Factors to Consider While Choosing a Concentric Vent Kit?

heating system vent

Ventilation is one of the essential components of gas-based home and water heating systems, as it enhances the system’s performance. That’s why you shouldn’t commence your search before consulting with a professional about possible ventilation solutions for your gas furnace or water heater.

In most cases, the manufacturer recommends the most suitable ventilation options for the particular model, so you should go through the unit’s manual to determine which ventilation system the unit’s manufacturer recommends.

Besides this information, there are several other factors you have to consider that can help you find the right concentric vent kit for your furnace or water heater, so let’s take a closer look at them.

Kit’s Compatibility

Concentric vent kits are not universal, and they usually fit just a handful of gas furnace or water heater models. That’s why you must check if the kit is compatible with the unit to which you want to connect it before setting to purchase it.

If your furnace or water heater arrived with a ventilation system, the safest option would be to get an identical one if you have to replace it. Also, you should consult with the contractor that will install the concentric vent kit and follow the recommendation they’ve given you.

The Dimensions of the Pipes

Comparing the size of the fitting that comes with the kit to the unit’s exhaust dimensions will ensure that you can connect it to the ventilation system you selected.

In addition, you should find out the diameter of the kit’s outer pipe so that you can calculate how wide the hole in the roof or wall should be.

Checking the length of the pipe will enable you to determine the unit’s location, but you should keep in mind that most models come with pipes that are between 30 and 40 inches long.

Installation Requirements

The kit’s installation manual contains the instructions and prerequisites for the successful installation of the ventilation system. For example, these instructions may include the list of materials used to seal the opening in the wall or how to assemble the kit.

These guidelines feature pre-installation requirements that must be met to avoid the appliance and causing gas leakage. You shouldn’t attempt to install a concentric vent kit by yourself if you’re not familiar with the process because you might end up causing an accident.

Cost and Durability

The PVC material components of concentric vent kits are made of, resist high temperatures well, which makes them more durable than conventional ventilation systems.

Even so, the kit’s durability depends on the model and the manufacturer, so you should try to find out its average life span before installing it. The price of these kits ranges from approximately $40 for entry-level models to $200 for high-end models.

It is worth adding that most manufacturers don’t offer a warranty for these kits, and you must replace the entire kit if any of its components break down.

The advantages of Concentric Vent Kits

The Simplified Installation Process of the Vent System

Conventional ventilation systems contain two pipes located next to each other that guide the gases away from the furnace and take the combustion air into the unit. Concentric vent pipes are located inside each other, which enables you to drill just one outlet hole.

Excellent Heat Resistance

The materials from which the components of these kits are made enable you to connect them to furnaces that have high AFUE ratings. Prolonged exposure to high temperatures does not affect the concentric vent, enabling you to use it for a long time without any risk of failure.

Multiple Installation Options

Concentric vents can be installed horizontally or vertically, which allows you to adjust them to the on-site conditions. You can also shorten the pipes if they’re too long for the setup you want to use them.

The Disadvantages of Concentric Vent Kits

Limited Compatibility

The vast majority of these kits are designed for a specific gas furnace or a water heater, and finding the model that fits the unit in your home can be difficult. You need to find out if the water heater or gas furnace is compatible with concentric vents before you decide to replace the unit’s original ventilation system.

Top 5 Concentric Vent Kits

DiversiTech CVENT-2

DiversiTech CVENT-2

The DiversiTech CVENT-2 kit can be installed horizontally or vertically, and you can choose if you want to guide the gases produced by the furnace through the wall or the roof.

The length of the pipes included in this kit is limited to 34.75 inches, affecting the unit’s position in a room. The kit is compatible with furnaces with 2-inch gas outlets and 2-inch gas inlets, and you must check if it is compatible with the unit you want to pair it with.


  • Made from durable materials
  • The rain cap prevents the humidity from entering the ventilation system
  • The kit can be installed horizontally and vertically
  • All connections required for successful installation are included in the kit


  • Limited compatibility
  • short pipes



The 3-inch wye fitting lets you connect the RHEEM SP20245 kit to gas furnaces with matching intake and exhaust vents. However, you should bear in mind that the hole in the wall for this kit needs to be more than 3 inches in diameter for the successful installation of the kit.

In addition, the kit contains multiple connections that allow you to adjust the position of the pipes to the space in which they are installed, as well as the rain cap that protects the ventilation system from moisture.


  • Long and adjustable pipes
  • Great for furnaces to water tanks with 3-inch exhaust and intake vents
  • Reasonable price
  • Functional design


  • The Complicated Pipe Extension Process
  • Some components of the kit aren’t durable

AO Smith 9006328005

AO Smith 9006328005

The AO Smith 9006328005 is designed for the Vertex™ GDHE-50 gas water heater and other models from the brand’s Vertex series. The accessory allows you to position the heating unit freely as the pipes are long enough to reach the opening in the wall or on the roof.

Even though the fully assembled kit ships, you still have to glue the joints and attach the rain cap, but it doesn’t contain the screws you’re going to need to fasten the rain cap.


  • simple assembly process
  • Allows for horizontal and vertical installation
  • The kit includes the wye fitting
  • It contains a grill that keeps prevents insects from entering the ventilation system.


  • Pipe connectors must be purchased separately
  • Not compatible with gas furnaces

Dakota Sourcing 22152

Dakota Sourcing 22152

You should take a closer look at the Dakota Sourcing 22152 kit if you need a concentric vent for a residential gas water heater. It is compatible with a variety of units with 2-inch exhaust and intake vents, but you still need to check if the kit can be used with the water heater you have.

The pipe’s length is limited to 34 inches, which forces you to position the water heater near the opening in the wall or the roof that should hold the pipe. This kit comes with a manual that contains the necessary information to install it.


  • Moderately priced
  • Effortless assembly
  • Excellent heat resistance
  • Great aftermarket solution


  • short pipe length
  • Limited compatibility

DiversiTech CVENT-4

DiversiTech CVENT-4

The DiversiTech CVENT-4 is a versatile kit that fits furnaces and water heaters with 4-inch intake and exhaust vents. The entire kit is made of thick PVC plastic that resists high temperatures well and stays in good condition for a long time.

You will have to drill a 5-inch hole in the roof or the wall to install this kit successfully, and you must assemble it before installation. The kit’s lower temperature rating is set to 32F, and exposure to extremely low temperatures can damage the pipe.


  • Compatible with high-efficiency furnaces and water heaters
  • Long and easily adjustable pipe
  • Affordable and durable
  • Excellent heat and cold resistance


  • Suitable only for units with 5-inch outlets and intakes
  • No warranty

Frequently Asked Questions about Concentric Vent Kits

Question: Can Concentric Vent Kits Replace Stainless Steel Ventilation Systems?

Answer: The concentric vent kits are usually made of PVC, and they can’t be installed in place of ventilation systems made of stainless steel.

Question: Are Concentric Vent Kits Pressurized?

Answer: The air and gases inside concentric vent kits aren’t pressurized.

Question: Is it Possible to Purchase the Components of Concentric Kits Separately?

Answer: In most cases, you will have to purchase the entire kit, as rarely sell components individually.

Question: How Long Do Concentric Vent Kits Last?

Answer: These kits are made from sturdy materials that can last for years if they’re not damaged.

Our Verdict: What is the Best Concentric Vent Kit For Your Furnace or Water Heater?

Ensuring that the gases generated by a furnace or water heater are safely guided outside of your home will make the entire heating system more efficient.

The concentric vent kits reduce the amount of work you have to go through to set up the heating system in your home as they only require one pipe outlet.

Despite having identical components, these kits are compatible with specific water heater and furnace models.

So, if you’re searching for a ventilation system you can use with a water heater from the Vertex series, you should consider getting the AO Smith 9006328005 kit.

On the other hand, a kit like the DiversiTech CVENT-2 can be a good solution for gas furnaces with 2-inch exhaust and inlet vents, but you must check its compatibility with your furnace.

We hope this guide has helped you find the best concentric vent kit for your gas-fired furnace or water heater system.

Let us know in the comments, or continue reading our guide to the best wood stoves if you’re searching for alternatives to gas furnaces.

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