Stacool 2PCS Air Parking Diesel Heater Exhaust Pipe,Stainless Steel 24mm Flexible Exhausts Pipe with Clamps,Diesel Heater Accessories Generator Exhaust Extension for Diesels Air Heaters

Tight spaces around a diesel air heater exhaust can turn a simple installation into a puzzle. I picked up the Stacool exhaust elbow kit to clean up a cramped routing job on a 5 kW parking heater in a van build, and after a few days of installs and runtime, I have a solid sense of where this kit shines and where it falls short.

What’s in the kit

You get two stainless 90-degree elbows and four worm-drive clamps. The elbows are compact—roughly three inches on each leg—intended for 24 mm exhaust systems. The clamps cover 18–29 mm, which fits most common corrugated stainless heater exhaust hoses. There’s no muffler, no straight pipe, and no gaskets—this is a focused solution for turning a corner and securing it.

Build quality and design

The elbows are made from stainless steel and feel robust. They held their shape during installation with no hint of kinking or collapsing at the bend. They’re not “flex pipes” in the sense that you can massage a new angle; they’re fixed 90s with just enough compliance to seat cleanly over a corrugated hose. That rigidity is a strength for durability and a limitation for fine tuning.

After several heat cycles, the elbows showed the typical straw-to-blue discoloration of stainless near the bend, but no warping, cracking, or seam issues. Threads on the included clamps are clean, though the bands are on the thinner side. They’re adequate for light to moderate vibration; if you’re mounting on a long, unsupported run or near a frame rail that transmits resonance, a higher-grade clamp (or dual clamping) is a smart upgrade.

One design note: the elbows are not swaged or stepped. Both ends are the same diameter, meant to slip over a 24 mm corrugated exhaust hose and be clamped. If your existing pipe is rigid tubing or you were hoping to slip one elbow inside another for a nested joint, this kit won’t do that without an adapter.

Installation and fit

The install process was straightforward:
- Cut the corrugated exhaust to length and deburr the cut edge.
- Slip the clamps over the hose first.
- Seat the elbow squarely over the hose, align the bend, and tighten the clamps.
- Repeat on the other side if you’re coupling two hoses with the elbow between.

Because the legs are short, the elbows are easy to position in tight bays and underbody channels. I used one elbow to drop the exhaust under a crossmember and a second to direct it away from a plastic splash guard. The compact geometry made it possible to maintain a gentle overall routing without introducing an overly long loop.

Clamping onto corrugated stainless always benefits from some finesse: I snugged each clamp, then rotated it slightly to find a land between ridges that would compress and seal. With reasonable care you can achieve a gas-tight joint without sealants. If you want belt-and-suspenders certainty, a thin smear of high-temp exhaust paste at the interface helps, but isn’t required.

Performance and noise

There’s no magic here—these elbows don’t add muffling—but rerouting the exhaust can reduce perceived noise inside the cabin. In my setup, pointing the outlet downward and away from the rocker panel trimmed some high-frequency rasp and killed a subtle drumming I was getting through the body. Backpressure remained a non-issue; the heater ramped up and down as normal, and exhaust temps at the outlet stayed consistent with a straight-run baseline.

Vibration at the joints was well controlled. The elbows’ rigidity actually helped prevent the hose from “wagging” at idle. I also didn’t detect any whistling or harmonic noise at higher fan speeds, which can happen with sloppier bends.

Heat and longevity

I ran several extended cycles, including full-load burns. The elbows took the heat without complaint. No loosening of clamps, no sooting at the joints, and no smell of hot volatiles—important if your routing passes near insulated panels. The stainless appears to be a mid-grade (likely 304). For road salt or marine environments, I’d still plan on periodic inspection; true 316 would be better around saltwater, but for automotive use this is more than serviceable.

Compatibility and limitations

A few things to check before you buy:
- Sizing: This kit targets 24 mm systems. Many heaters use 24 mm, but some use 22, 25, or 26 mm. Measure your hose OD and the mating hardware. The clamp range (18–29 mm) gives some leeway, but you still need a proper fit to the elbow’s tubing.
- Connection type: If your existing exhaust is rigid tube rather than corrugated hose, you’ll need a coupler or reducer. The elbows aren’t stepped for slip-fit into another rigid pipe.
- Bend radius: You get a sharp 90. If you need a sweeping bend for smoother flow or to clear a long obstruction, a flexible stainless section might be a better choice.
- Space: The overall envelope is small, but the fixed 90 means you can’t “cheat” the angle. In very tight installs, two shallow bends or a flexible section can be more forgiving.

Practical tips from the install

• Pre-fit dry, then mark clamp positions with a paint pen so you can reassemble quickly in the right orientation.
• Don’t over-torque the clamps; corrugated hose can deform. Tighten until you see even compression around the circumference and then add a quarter-turn.
• Maintain a slight downward slope to the outlet to prevent condensate pooling.
• Keep at least an inch of air gap from plastics, wiring looms, and fuel lines. Where that’s not possible, add a small heat shield.
• If you’re routing near a body panel, consider a small standoff bracket to remove weight from the elbow joint and reduce transmitted vibration.

How it compares and value

There are more elaborate exhaust kits for diesel heaters that include mufflers, flexible runs, and pre-swaged ends. Those are great when you’re fabricating a full system from scratch. The Stacool kit feels purpose-built for tweaks and corrections: turning a corner neatly, avoiding a heat-sensitive component, or adapting an existing run after you discover an interference.

For the price, getting two elbows and four clamps is reasonable value. The stainless quality and consistent bends inspire confidence. I would budget a few extra dollars for upgraded clamps if your install sees heavy off-road use or you simply prefer a more robust fastener. Otherwise, the included hardware gets the job done.

What I’d change

• A swaged end on each elbow would allow a slip-fit into rigid tubing or another elbow, expanding compatibility without adapters.
• Slightly heavier clamps would be a welcome bump, even if it raised the price a touch.
• A short length of matching straight pipe in the box could help bridge gaps and would make this a more complete mini-routing kit.

Bottom line

The Stacool exhaust elbow kit is a simple, sturdy solution for redirecting a diesel heater’s exhaust in tight spaces. It’s correctly sized for common 24 mm systems, stands up to heat, and installs without drama. Its fixed 90-degree design and same-diameter ends limit some flexibility, so measure carefully and plan your joints. For most van, RV, and shop installs where you just need to make a clean turn and seal it, it delivers.

Recommendation

I recommend this kit for anyone running a 24 mm diesel air heater who needs reliable 90-degree turns and a compact routing footprint. It’s durable, heat-resistant, and easy to install, with just enough hardware to complete two corners. If your system uses rigid tubing or a different diameter, or if you require adjustable bends, look elsewhere or plan on adding adapters. But for common corrugated-hose setups, this is a straightforward, cost-effective fix that performs as expected.