Anti-Down Draught Chimney Cowl (CAGI Deflector)
The indicated price is valid ordering till 12.09.2026.
RENOFAST Stainless Steel Aerodynamic Chimney Cowl (Anti-Downdraught)
Product Description
The RENOFAST aerodynamic cowl is a static device designed to stabilise and enhance natural draught in chimney and ventilation systems. It is installed at the very top of the chimney pipe.
Operating Principle: The design utilises wind energy for the benefit of your heating system. Airflows flowing around the cowl body accelerate and create a low-pressure zone inside the cylinder (Bernoulli principle). This physical phenomenon literally "sucks" flue gases out of the pipe, ensuring stable exhaust of combustion products even in weak winds.
Furthermore, the device acts as a reliable shield against back-draught. The outer cylinder dampens lateral wind gusts, preventing them from "blowing out" the flame or driving smoke back into the room. This is the ideal solution for houses located in open terrain or areas with unpredictable wind loads.
Features and Benefits
- Wind Protection: The cylindrical body effectively breaks up airflows, protecting the chimney from downdraughts even during gale-force winds.
- Fuel Economy: Stable draught ensures complete combustion of firewood or coal, increasing the efficiency of the heating appliance.
- Comprehensive Protection: A classic rain cap is hidden inside the device, preventing precipitation (rain, snow) and debris from falling directly into the chimney channel.
- Reliability: Unlike rotary turbines, there are no bearings or rotating parts here. The cowl will not jam due to soot, ice, or corrosion — it works as long as the wind blows.
- Material: Manufactured from acid-resistant stainless steel AISI 304L/316L, resistant to aggressive combustion products.
Technical Specifications
| Element Type | Aerodynamic Cowl (Static) |
| Operating Principle | Static (Non-rotating) |
| Construction | Spigot + Diffuser + Outer Body + Cap |
| Material | Stainless Steel AISI 304L / AISI 316L |
| Steel Thickness | from 0.6 mm |
| Certification | CE |
Application Recommendations
- Purpose: Strongly recommended for solid fuel boilers, fireplaces, and stoves if the house experiences draught problems, smoke spillage during lighting, or the boiler being blown out by the wind.
- Installation: The cowl is installed on the top chimney pipe. The device has high wind resistance ("sail effect"), so it must be securely fixed to the pipe with stainless steel rivets or self-tapping screws.
- Maintenance: The device requires no lubrication. Maintenance is limited to periodic (1-2 times a year) cleaning of soot along with the main chimney channel.
