The best 3-inch by 5-inch concentric vent choice depends on the appliance, venting requirements, and length needed. The DuraVent 24-inch and 36-inch pipes suit buyers looking for different straight-pipe lengths. The VATTCEEL kit is a short stainless-steel option, while the DiversiTech kit is designed for 3-inch concentric vent applications. The RTG20151R is another short 3-inch/5-inch straight vent. Check the appliance manufacturer’s instructions before choosing: similar dimensions alone do not confirm that a vent is approved for a particular appliance.
| Product | Listed size or length | Best suited for |
|---|---|---|
| DuraVent 35CVS-24 | 3 x 5 inches; 24 inches long | A shorter straight-pipe section |
| DuraVent 35CVS-36 | 3 x 5 inches; 36 inches long | A longer straight-pipe section |
| DiversiTech CVENT-3 | 3-inch concentric kit | Buyers seeking a low-profile kit |
| VATTCEEL 3 x 5 Vent Kit | 12-inch straight pipe | Buyers seeking a stainless-steel kit |
| RTG20151R Straight Vent | 11.66 inches; 3″/5″ | Buyers needing a compact straight vent |
DuraVent 35CVS-24 24-Inch Pipe
This DuraVent concentric vent system pipe measures 3 by 5 inches and is 24 inches long. Its listed feature is an easy in-and-out fit. It is the shorter of the two DuraVent lengths in this comparison, making it best for buyers whose layout calls for a 24-inch section.
Why it was selected: It provides a clearly specified 3 x 5-inch size and a middle-range length among the listed straight-pipe options. Choose this if 24 inches matches the installation plan and appliance instructions.
Limitation: The provided product details do not specify all connection or appliance compatibility requirements. Confirm fit with the manufacturer’s documentation before ordering.
DuraVent 35CVS-36 36-Inch Pipe
This model has the same listed 3 x 5-inch size and easy in-and-out fit as the 24-inch DuraVent pipe, but it is 36 inches long. It is best for buyers whose planned straight run needs the longer section.
Why it was selected: The 36-inch length gives buyers a direct alternative to the 24-inch version without changing the listed size. Choose it when the extra length suits the installation design; do not assume a longer pipe can replace a required vent configuration.
Limitation: The listing details provided do not identify specific appliance models or all installation requirements. Verify approved vent lengths and connections in the appliance manual.
DiversiTech CVENT-3 Concentric Kit
DiversiTech describes this as a 3-inch concentric vent kit for tankless gas water heaters and high-efficiency furnaces. Its dual-pipe configuration is intended to streamline installation, and its low-profile design conceals intake and exhaust pipework for a tidier appearance. The listed dimensions are 7.75 x 40 x 6.75 inches.
Best for: Buyers looking for a kit-style, low-profile venting option for an appliance type identified in the product description. It was selected because its listed purpose specifically mentions high-efficiency furnaces and tankless water heaters.
Limitation: The product is described as a 3-inch kit, not as a 3 x 5-inch straight pipe. Confirm that its configuration is the one required by the appliance manufacturer.
VATTCEEL 3 x 5 Stainless-Steel Kit
This kit includes one 3 x 5-inch straight pipe measuring 12 inches. The product description names Rinnai, Navien, Rheem, and A.O. Smith among the brands it is compatible with. It is made from 304 stainless steel, which the listing describes as corrosion-resistant and suitable for high-temperature conditions.
Best for: Buyers seeking a short stainless-steel vent kit and a listing that names several tankless water-heater brands. It was selected for its stated dimensions, material, and named compatibility.
Limitation: The listing says it is compatible with “most” 3 x 5-inch gas tankless water heaters, which does not establish compatibility with every model. Check the exact appliance manual and vent requirements.
RTG20151R 11.66-Inch Straight Vent
The RTG20151R is listed as a 3-inch/5-inch concentric straight vent measuring 11.66 inches. Its product details describe durable materials for long-lasting performance, but do not provide a specific material in the information available here.
Best for: Buyers who need a compact straight vent with a listed length just under 12 inches. It was selected as another short 3″/5″ option for comparison with the 12-inch VATTCEEL pipe.
Limitation: The available features do not identify appliance compatibility, connection details, or material type. Confirm these specifications before selecting it for an installation.
Buying Guide: How To Choose A 3 x 5 Concentric Vent
Does the appliance require a concentric kit or a straight pipe?
These are not interchangeable product descriptions. A kit may provide a particular intake-and-exhaust arrangement, while a straight pipe is a length of vent pipe. Check the appliance manual for the specified vent type, dimensions, approved components, and installation configuration before comparing products.
Which length should you choose?
Compare the listed length with the planned vent run and the appliance’s permitted venting design. The products here range from 11.66 to 36 inches. Do not choose a longer or shorter section based only on convenience; the total vent arrangement must follow the manufacturer’s instructions.
Does the product name establish compatibility?
No. Size alone does not confirm compatibility. The VATTCEEL listing names several brands, but buyers should still check the exact appliance model. The other products provide varying levels of compatibility information, so verify requirements directly with the appliance documentation.
Should material and appearance affect the choice?
Material claims may help narrow options when they match the installation needs. VATTCEEL specifies 304 stainless steel, while the DiversiTech description emphasizes a low-profile appearance. Compare these stated features with the required installation conditions rather than assuming every product has the same material or finish.
Frequently Asked Questions
What does 3 x 5 mean for a concentric vent?
It identifies the listed vent size as 3 inches by 5 inches. Check the appliance documentation to confirm that those dimensions and the product configuration are appropriate.
Are a concentric vent kit and a straight pipe the same thing?
No. A kit and a straight pipe are different product descriptions. Select the type specified by the appliance manufacturer.
Which listed product is 36 inches long?
The DuraVent 35CVS-36 is listed as a 3 x 5-inch concentric vent pipe with a 36-inch length.
Which product specifically lists stainless steel?
The VATTCEEL kit lists 304 stainless steel and includes one 12-inch 3 x 5-inch straight pipe.
Can these products be used with any tankless water heater?
No universal compatibility is established by the provided details. Confirm the exact vent requirements for the specific appliance model before buying.