Answering your search for the best double wall flue pipe, this guide highlights durable, stainless-steel, and class-A options designed for safe venting of wood, pellet, and multi-fuel stoves. Ideal buyers include homeowners upgrading an existing chimney, new stove installations, or HVAC professionals seeking reliable double-wall systems. Below are five top choices with practical differences to help you pick the right fit. A quick summary table follows to compare core specs at a glance.
| Product | Best For | Key Benefit |
|---|---|---|
| AllFuel HST 6″ x 48″ | AllFuel HST Class-A users | 2″ clearance to combustibles with ceramic fiber insulation |
| AllFuel HST 6″ x 36″ | Compact installations | Same 304 stainless steel build and insulation in a shorter length |
| Selkirk 6″ SureTemp 48” | High-heat applications | UL-listed to 2100°F, robust double-wall design |
| DuraVent PelletVent Horizontal Kit (3 in) | Horizontal pellet/multi-fuel venting | Complete kit for safe horizontal through-the-wall venting |
| AllFuel HST 8″ x 36″ | Larger-diameter installs | Consistent draft with 2″ clearance and stainless steel |
AllFuel HST 6″ x 48″ Double Wall Pipe
Reference features: 304 stainless steel inner and outer walls with laser welded seams, maximum corrosion resistance, and ceramic fiber blanket insulation providing a 2″ clearance to combustibles while maintaining high internal temperatures for proper draft. This option is compatible with AllFuel HST Class-A double wall pipe, but cannot connect to other brands’ class-A systems. Best for buyers already using AllFuel HST components who need a long run with durable insulation.
Best for: Homeowners or installers who require a long, seamless run with strong corrosion resistance and a guaranteed 2″ clearance to combustibles. Choose this if your chimney path is extended or you’re replacing an existing AllFuel HST run.
Caution: Not compatible with non-AllFuel Class-A chimney brands. Ensure proper fit with your existing AllFuel HST components.
AllFuel HST 6″ x 36″ Double Wall Pipe
Reference features: 304 stainless steel inner and outer walls with laser welded seams, insulated with ceramic fiber blanket to maintain a 2″ clearance to combustibles while promoting proper draft. Compatible with AllFuel HST Class-A pipes only. Best for: compact installations where space is limited but you still want reliable Class-A performance.
Best for: Projects needing a shorter segment without sacrificing the double-wall insulation benefits. Consider this when closet or utility areas constrain pipe length.
Caution: Limited to AllFuel HST Class-A systems; not interchangeable with other brand Class-A pipe.
Selkirk 6″ SureTemp 48” Double-Wall Pipe
Reference features: Double-wall stainless steel inner liner and durable outer casing, UL-listed and tested up to 2,100°F for surge protection, designed for venting wood, coal, oil, or gas heating appliances. Best for: high-temperature applications where reliable safety margins are essential. Better for: installations requiring strong heat resistance and long-term durability.
Best for: Systems that may encounter rapid temperature spikes, such as dense wood-burning setups. Avoid if your installation has strict brand compatibility requirements with non-Selkirk parts.
Caution: Higher-heat ratings are beneficial, but ensure compatible components and clearances in your overall venting plan.
DuraVent PelletVent Horizontal Double-Wall Kit, 3 in
Reference features: Complete kit with five 12-inch pipes, 90-degree elbow tee, cleanout tee with cap, appliance adapter, wall thimble, horizontal termination cap, and installation instructions. Designed for pellet and multi-fuel stoves requiring double-wall venting for safe horizontal through-the-wall installation. Best for: homeowners venting pellet stoves horizontally where neat, code-compliant routing is needed.
Best for: Horizontal venting projects where a full kit streamlines installation. Better for: pellet stove setups needing a secure, ready-to-use kit. Caution: As a 3-inch system, it may not fit larger appliance outlets without adapters.
AllFuel HST 8″ x 36″ Double Wall Pipe
Reference features: 304 stainless steel inner and outer walls, laser welded seams for corrosion resistance, and ceramic fiber insulation maintaining a 2″ clearance to combustibles while preserving high flue temperatures for draft. Best for: larger-diameter stove venting where robust insulation and durability are required. Better for: installations that need a balance of length and diameter without sacrificing safety margins.
Best for: projects requiring an 8-inch diameter run with reliable draft control. Caution: Larger diameter pipes require appropriate clearances and support structures; verify fit with existing hardware.
Buying Guide
- What is double-wall flue pipe and why it matters: Double-wall construction provides insulation and a cooler exterior, reducing heat transfer to surrounding materials and improving safety and draft consistency.
- Material and compatibility: Stainless steel inner and outer walls resist corrosion and provide long-term durability. Only mix compatible brand components when specified by the manufacturer to maintain warranty and performance.
- Insulation type and clearance: Ceramic fiber blankets typically support a 2″ clearance to combustibles while preserving internal flue temperatures. Ensure your install meets local code requirements.
- Diameter and length: Choose a size that matches your stove outlet and the path to the chimney. Longer runs may need additional support or heat management considerations.
- Horizontal vs vertical venting: Horizontal kits are available for pellet stoves; ensure proper through-wall routing and termination clearances. Vertical runs generally require different fittings and supports.
- Temperature ratings and safety: Look for UL listing or equivalent certifications, especially for high-heat appliances. Severity of heat events should factor into your selection.
FAQ
- Q: Can I mix brands of double-wall Class-A chimney pipe?
A: Generally not recommended. Brand-specific connections ensure proper fits and fire safety approvals. - Q: What is the 2″ clearance to combustibles?
A: It’s the minimum distance between the pipe and any combustible material, achieved by the insulation thickness. - Q: Which pipe is best for pellet stoves?
A: Kit options like the DuraVent PelletVent Horizontal Kit are designed for horizontal pellet venting, while AllFuel HST options provide strong Class-A performance. - Q: Do larger diameters require more support?
A: Yes. Larger pipes need appropriate brackets and supports to prevent sagging and ensure proper draft. - Q: Are stainless steel pipes more durable than galvanized?
A: Yes, stainless steel resists corrosion better over time, especially in high-temperature or humid environments.