Concentric Exhaust System
Concentric Exhaust System Concentric Exhaust System, Customer Photo Concentric Exhaust System Concentric Exhaust System - Tee Fitting video

Concentric Exhaust System



  • Steam Pipe insulates the Smoke Pipe and allows for zero clearance from combustibles
  • Dramatically increased natural draw in Steam Pipe
  • Hot embers are extinguished by the steam when they reach open air
  • Requires only ONE roof penetration
    • Reduces risk of roof leaks
    • Reduces potential roof jams
  • Cost is comparable to other systems
  • Easier hood removal on your evaporator
  • Condensation drain
    • Evacuates both condensation and rain
    • Prevents rust from developing in your arch


  • Stainless Steel 90º Elbow (attaches to hood)
  • Stainless Steel “T” (connects the base stack, strap stack and vertical pipes)
  • Stainless Steel Strap Stack (connects the “T” and the 90º Elbow)
  • Gaskets and Hardware for Strap Stack
  • Stainless Steel Concentric Fins (Keeps the smoke stack centered within the steam stack)
  • Assembly Guide
  • (NOTE: Round, Stainless Steel Stack Pipe sold separately.)


This system is compatible with all Smoky Lake Fitted Hoods. It is not designed for use with suspended hoods nor competitor hoods.


Select your Smoke Pipe diameter, below, to receive a quote. Then, enter the measurements from the Dimensions Worksheet to ensure perfect fitment.

If you are unsure about a dimension, you may write “contact me” in that field. Please note, we may not be able to start production on you Concentric Exhaust System until your dimensions have been confirmed.


Measurement “A” (inches) * 

Please refer to the dimensions worksheet and confirm the diameter of the hub on your Smoky Lake Fitted Hood.

Measurement “B” (inches) * 

Please refer to the dimensions worksheet and confirm the diameter of the top of your Base Stack.

Measurement “C” (inches) * 

Please refer to the dimensions worksheet and confirm the distance between your Smoky Lake Fitted Hood’s top Hub and your Base Stack. This should be the distance from center to center.

Measurement “D” (inches) * 

Please refer to the dimensions worksheet and confirm the distance from the TOP of your Smoky Lake Fitted Hood’s Hub to the top of your Arch rail.

Measurement “E” (inches) * 

Please refer to the dimensions worksheet and confirm the measurement from the bottom of your Base Stack to the top bead of the Base Stack. Do NOT include the top crimped edge of the Base Stack in your measurement.

Type of Pan Being Used * 

What is the model of the Smoky Lake pan that will be used with this system. (ie. Hybrid Pan vs Drop Flue Pan Set vs Raised Flue Pan Set)

Overall Size of the Pan(s) * 

Please confirm the overall footprint of your pan(s). For example, if you have a 2×2 Front Pan with a 2×4 Flue Pan, your total footprint would be 2×6.


Assembly Instructions

The cooler steam pipe completely surrounds and insulates the extremely hot inner smoke pipe, allowing you zero clearance to combustibles and making a safer environment in the sugarhouse.

The hot inner smoke pipe dramatically increases the natural draw of the steam pipe. This creates a negative pressure inside the steam hoods, thus reducing steam in the sugarhouse.

The steam exhaust surrounds the inner smoke pipe. This will greatly reduce fire danger by immediately extinguishing hot embers and sparks as they enter open air.

The Concentric Exhaust System allows for only one roof penetration, instead of two or even three. This will reduce the potential for roof leaks and snow jams.

The Concentric Exhaust System requires only one roof jack for roof penetration and one stack cover. Other systems require two or even three. Each roof jack costs $400 – $500, each stack cover costs about $200. The savings in roof jack expense and stack cover expense normally covers the expense of this upgrade; or more than covers it.

The horizontal pipe extending from the top of the hood to the tee fitting is a removable strap stack. This makes hood removal many times easier than a normal scenario where the weight of the long vertical stack pipe is resting on the hood.

On the outer pipe — located at the bottom of the tee fitting — is a condensation drain. This will control any water that might develop in the pipe from condensation and will also control and evacuate any rain water that might enter the system from above the roof. This prevents moisture from running down onto the arch and causing rust as it would with a traditional system.

This Is What It Boils Down To

Sizes of the Concentric Pipe Pairs

Outer Pipe Diameter (Steam) Inner Pipe Diameter (Smoke)
12″ 8″
14″ 10″
17″ 12″
20″ 14″
Builder Spec Sheet


There are no reviews yet.

Be the first to review “Concentric Exhaust System”

14 + 19 =