Wood Burning Stove Rear Flue Options (Expert Rear-Vent Guide)

Understanding Rear Flue Options for Wood Burning Stoves: An Expert Guide

Rear flue exits on wood stoves offer a space-saving alternative to top exits, especially in tighter rooms or when dealing with low ceilings. But choosing this option requires careful consideration of several factors. From proper clearances to optimal draft, I’ll walk you through everything you need to know to ensure a safe and efficient installation.

Why Consider a Rear Flue Exit?

For many homeowners, the decision to opt for a rear flue exit comes down to space and aesthetics. In smaller rooms, a rear exit allows the stove to sit closer to the wall, maximizing usable area. Aesthetically, some people prefer the cleaner look of a rear exit, as it can minimize the visible flue pipe.

• Space Saving: Ideal for compact living spaces.
• Aesthetic Appeal: Offers a cleaner, less obtrusive look.

Initial Considerations Before Choosing a Rear Flue

Before you even think about purchasing a stove with a rear flue exit, there are several crucial factors to consider. These include local building codes, chimney height, and the overall layout of your room.

• Local Building Codes: Always consult your local building codes for specific requirements regarding wood stove installations.
• Chimney Height: Ensure your chimney is tall enough to provide adequate draft.
• Room Layout: Consider the placement of furniture and other appliances to ensure proper clearances.

Detailed Steps for Installing a Rear-Vented Wood Stove

Installing a rear-vented wood stove is not a task to be taken lightly. It requires careful planning, precise measurements, and a thorough understanding of safety protocols. I cannot stress this enough, if you aren’t comfortable with this process, hire a professional. Your safety and the safety of your home depend on it.

Step 1: Planning and Preparation

The first step in any successful wood stove installation is meticulous planning. This involves assessing your existing chimney, measuring clearances, and gathering the necessary tools and materials.

• Chimney Inspection: Have your chimney professionally inspected to ensure it’s clean, structurally sound, and properly sized for your stove.
• Clearance Measurements: Measure the distance from the stove to any combustible materials (walls, furniture, etc.). Consult your stove’s manual for specific clearance requirements.

• Tool and Material List:

  • Wood stove
  • Chimney liner (if needed)
  • Stove pipe (24 gauge or thicker)
  • Elbows (45 or 90 degree, depending on your setup)
  • Wall thimble
  • Non-combustible hearth pad
  • Heat-resistant gloves
  • Safety glasses
  • Screwdrivers, wrenches, drill
  • Level
  • Measuring tape
  • Pencil
  • Smoke detector
  • Carbon monoxide detector

Step 2: Preparing the Chimney

If your existing chimney is not suitable for wood stove use, you may need to install a chimney liner. This is a flexible stainless steel pipe that runs the length of your chimney, providing a safe and efficient pathway for the exhaust gases.

• Liner Installation: Carefully lower the chimney liner down the chimney, ensuring it is properly connected to the stove pipe adapter.
• Insulation: Insulate the liner to improve draft and reduce creosote buildup. This can be done using a wrap-around insulation blanket or by pouring vermiculite down the chimney around the liner.

Step 3: Installing the Wall Thimble

The wall thimble is a crucial component that protects combustible walls from the heat of the stove pipe. It consists of two metal rings separated by a layer of insulation.

• Locate Studs: Use a stud finder to locate the wall studs in the area where you plan to install the thimble.
• Cut Hole: Cut a hole in the wall that is large enough to accommodate the thimble. The size of the hole will depend on the diameter of your stove pipe and the thickness of your wall.
• Install Thimble: Slide the thimble into the hole, ensuring it is flush with the wall on both sides. Secure it to the studs using screws or nails.

Step 4: Connecting the Stove Pipe

The stove pipe connects the stove to the chimney, carrying the exhaust gases away from the stove. It is important to use high-quality stove pipe that is specifically designed for wood stove use.

• Attach First Section: Attach the first section of stove pipe to the stove’s flue collar, using screws to secure it in place.
• Connect Elbows: If necessary, use elbows to connect the stove pipe to the wall thimble. Ensure the elbows are properly aligned and securely fastened.
• Insert into Thimble: Carefully insert the stove pipe through the wall thimble and into the chimney liner adapter.

Step 5: Final Checks and Testing

Once the stove pipe is connected, it’s time to perform a final inspection and test the stove.

• Inspect Connections: Double-check all connections to ensure they are tight and secure.
• Clearances: Verify that all clearances to combustible materials meet the requirements specified in the stove’s manual.
• Smoke Test: Perform a smoke test to check for leaks in the stove pipe or chimney. Light a small fire in the stove and observe the smoke. If you see smoke escaping from any of the connections, tighten them or replace the damaged components.
• Carbon Monoxide Test: Install a carbon monoxide detector in the room and test it to ensure it is working properly.

Addressing Common Challenges with Rear Flue Installations

Rear flue installations, while offering certain advantages, can also present unique challenges. Here are some common issues I’ve encountered and how to address them:

Draft Issues

One of the most common problems with rear flue installations is poor draft. This can be caused by a variety of factors, including:

• Insufficient Chimney Height: The chimney may not be tall enough to create adequate draft.
• Cold Chimney: A cold chimney can impede the flow of exhaust gases.
• Obstructions: The chimney may be blocked by debris or creosote buildup.

Solutions:

• Increase Chimney Height: Extend the chimney by adding a section of stove pipe.
• Insulate Chimney: Insulate the chimney to keep it warm and improve draft.
• Clean Chimney: Have the chimney professionally cleaned to remove any obstructions.

Creosote Buildup

Creosote is a flammable substance that can accumulate in the chimney and stove pipe. It is formed when wood burns incompletely, and the resulting smoke condenses on the cool surfaces of the chimney.

Solutions:

• Burn Dry Wood: Only burn wood that has been properly seasoned (dried) for at least six months.
• Maintain Hot Fires: Burn hot fires to ensure complete combustion and reduce creosote formation.
• Regular Chimney Sweeping: Have the chimney professionally swept at least once a year, or more often if you burn wood frequently.

Clearance Issues

Maintaining proper clearances to combustible materials is essential for preventing fires. If the stove is too close to a wall or other combustible surface, the heat can cause the material to ignite.

Solutions:

• Increase Clearances: Move the stove further away from combustible materials.
• Install Heat Shield: Install a heat shield on the wall behind the stove to reduce the amount of heat that is radiated to the wall.

Optimizing Performance and Safety of Your Rear-Vented Stove

Once your rear-vented wood stove is installed, it’s important to take steps to optimize its performance and ensure its safety.

Wood Selection and Storage

The type of wood you burn and how you store it can have a significant impact on the stove’s performance and the amount of creosote that is produced.

• Hardwoods vs. Softwoods: Hardwoods, such as oak, maple, and ash, are denser and burn longer than softwoods, such as pine and fir.
• Seasoning: Wood should be seasoned for at least six months before burning. This allows the moisture content to drop to 20% or less, which results in a hotter, cleaner burn.
• Storage: Store wood in a dry, well-ventilated area. Cover the wood to protect it from rain and snow.

Regular Maintenance

Regular maintenance is essential for keeping your wood stove in good working condition and preventing problems.

• Ash Removal: Remove ash from the firebox regularly.
• Stove Pipe Inspection: Inspect the stove pipe regularly for signs of damage or creosote buildup.
• Gasket Replacement: Replace worn or damaged gaskets on the stove door and flue collar.

Safety Precautions

• Smoke and Carbon Monoxide Detectors: Install smoke and carbon monoxide detectors in the room and test them regularly.
• Fire Extinguisher: Keep a fire extinguisher nearby in case of a fire.
• Child Safety: Keep children away from the stove and teach them about fire safety.

Advanced Techniques for Efficient Wood Burning

Beyond the basics, there are several advanced techniques that can help you burn wood more efficiently and reduce emissions.

Top-Down Burning

Top-down burning is a technique where the fire is started at the top of the wood pile and burns downward. This results in a hotter, cleaner burn with less smoke.

How to do it:

1. Place several large pieces of wood at the bottom of the firebox.
2. Stack smaller pieces of wood on top of the larger pieces.
3. Place kindling and a fire starter on top of the small pieces.
4. Light the fire starter and let it burn down.

Air Control

Most wood stoves have an air control that allows you to adjust the amount of air that is fed to the fire. By adjusting the air control, you can control the rate at which the wood burns and the amount of heat that is produced.

Tips for air control:

• Start with the air control fully open to get the fire going.
• Once the fire is burning well, gradually close the air control to reduce the rate of burning.
• If the fire starts to smolder, open the air control to increase the airflow.

Catalytic vs. Non-Catalytic Stoves

Catalytic stoves use a catalytic combustor to burn off the smoke and gases that are produced during combustion. This results in a cleaner, more efficient burn. Non-catalytic stoves do not have a catalytic combustor and rely on other methods to reduce emissions.

Advantages of catalytic stoves:

• Lower emissions
• Higher efficiency
• Longer burn times

Disadvantages of catalytic stoves:

• Higher cost
• More maintenance

Troubleshooting Common Issues with Rear-Vented Stoves

Even with proper installation and maintenance, you may encounter problems with your rear-vented wood stove. Here are some common issues and how to troubleshoot them:

Smoke Coming into the Room

If smoke is coming into the room when you open the stove door, it could be caused by:

• Poor Draft: The chimney may not be providing enough draft to pull the smoke up the chimney.
• Blocked Chimney: The chimney may be blocked by debris or creosote buildup.
• Damper Closed: The damper in the stove pipe may be closed.

Solutions:

• Check Chimney Height: Ensure the chimney is tall enough to provide adequate draft.
• Clean Chimney: Have the chimney professionally cleaned to remove any obstructions.
• Open Damper: Make sure the damper in the stove pipe is fully open.

Stove Not Producing Enough Heat

If the stove is not producing enough heat, it could be caused by:

• Wet Wood: The wood may be too wet to burn efficiently.
• Air Control Closed: The air control may be closed too far, restricting airflow to the fire.
• Dirty Stove: The stove may be dirty, which can reduce its efficiency.

Solutions:

• Burn Dry Wood: Only burn wood that has been properly seasoned.
• Open Air Control: Open the air control to increase airflow to the fire.
• Clean Stove: Clean the stove regularly to remove ash and creosote.

Excessive Creosote Buildup

If you are experiencing excessive creosote buildup, it could be caused by:

• Wet Wood: Burning wet wood can cause excessive creosote buildup.
• Low Fire Temperatures: Burning low fires can also cause creosote buildup.
• Restricted Airflow: Restricted airflow can cause incomplete combustion and creosote buildup.

Solutions:

• Burn Dry Wood: Only burn wood that has been properly seasoned.
• Burn Hot Fires: Burn hot fires to ensure complete combustion.
• Ensure Adequate Airflow: Make sure the stove is getting enough air.

The Future of Wood Burning Stoves: Innovations and Trends

The world of wood burning stoves is constantly evolving, with new technologies and innovations emerging all the time. Here are some of the trends that I’m seeing:

EPA Regulations

The Environmental Protection Agency (EPA) has been tightening regulations on wood burning stoves in recent years. These regulations are designed to reduce emissions and improve air quality.

Impact of EPA regulations:

• New stoves must meet stricter emissions standards.
• Older, less efficient stoves may be phased out.
• Consumers may need to purchase new stoves to comply with regulations.

Smart Stoves

Smart stoves are equipped with sensors and controls that allow you to monitor and adjust the stove’s performance remotely. These stoves can also provide data on wood consumption, emissions, and efficiency.

Benefits of smart stoves:

• Improved efficiency
• Reduced emissions
• Convenient remote control

Alternative Fuels

In addition to wood, some stoves can burn alternative fuels such as pellets, corn, and biomass. These fuels can be more sustainable and environmentally friendly than wood.

Advantages of alternative fuels:

• Renewable resources
• Lower emissions
• Convenient to store and handle

Case Studies: Real-World Rear Flue Installations

To illustrate the principles discussed in this guide, let’s examine a few real-world case studies of rear flue installations I’ve personally been involved with.

Case Study 1: The Tight Space Challenge

Situation: A homeowner in a small Vermont cabin wanted to install a wood stove but had limited space. A rear flue exit was the only viable option.

Challenge: Ensuring proper clearances in a confined space.

Solution: We used a combination of heat shields and precise measurements to meet the clearance requirements. We also opted for a smaller, more compact stove model.

Outcome: A safe and efficient installation that provided ample heat without compromising space.

Case Study 2: The Drafty Chimney Dilemma

Situation: An old farmhouse with a tall, uninsulated chimney was experiencing significant draft issues with a rear-vented stove.

Challenge: Overcoming the negative effects of a cold, drafty chimney.

Solution: We installed a fully insulated chimney liner to improve draft and reduce creosote buildup.

Outcome: A dramatic improvement in draft and overall stove performance.

Case Study 3: The Modern Aesthetic Preference

Situation: A homeowner with a contemporary home desired a wood stove but wanted to minimize the visual impact of the flue pipe.

Challenge: Balancing aesthetics with safety and performance.

Solution: We used a rear flue exit with black stove pipe and carefully concealed the pipe behind a decorative panel.

Outcome: A visually appealing installation that met all safety requirements and provided efficient heating.

Conclusion: Mastering the Art of Rear Flue Wood Stove Installation

Rear flue wood stove installations can be a great solution for certain situations. They are not without their challenges, but with careful planning, proper installation, and regular maintenance, you can enjoy the warmth and comfort of a wood stove for many years to come. Remember, safety should always be your top priority.

Learn more