For effective operation of the cooker hood it is important the correct choice of air ducts. With the advent of the construction market of plastic pipes mounted ventilation communication has become easier and cheaper. Plastic ventilation ducts become an affordable alternative to galvanized ducts for exhaust.
Specifications and features
For the manufacture of plastic ducts used 4 kinds of polymers: polyethylene, polypropylene, polyvinyl chloride (PVC), Teflon (PVDF). Consider the characteristics of each species.
Polyethylene plastic ducts are mainly used in suburban homes with a seasonal residence. They have UV protection and anti-static coating. Polyethylene is resistant to temperature extremes, it can be used outside and inside. Safe operation of polyethylene pipes is guaranteed in a range from - 45C to + 75C.
Polypropylene ducts are used to connect the hood because of the low cost and ease of installation. Polypropylene is a good insulator, resistant to aggressive media, but can not withstand low temperatures, so is used only in a warm room.
Important! When the temperature exceeds the norm + 85C flammable material and melts easily. You can find varieties with fire-resistant components.
The main quality of the ventilation ducts of PVC - lightness, rugged construction and affordable price. The temperature range for effective operation from 0C to 80C, a temperature below zero is not transferred. Heating above + 120 ° C is a health hazard, the product starts to allocate chlorine. PVC pipes are widely used for mounting the hood when the temperature during use does not exceed the recommended threshold.
Ventilation ducts of polytetrafluorethylene are durable and resistant to aggressive media. They are able to withstand the acid-base pair, so mostly used for ventilation of aggressive air flow in the workplace. safe operating temperature from -40C to + 140C. Due to the high cost and increased permeability of the material they are rarely used in the apartment.
Advantages and disadvantages of the ventilation plastic pipes
Ducts made of plastic have the following advantages:
- light weight;
- complete tightness;
- low noise levels;
- finished look that does not require painting;
- ease of installation;
- corrosion resistance;
- toxic safety;
- produce minimum static air flow resistance;
- easily disassembled for installation in another embodiment;
- antistatic treatment prevents dust settling within the system.
Disadvantages:
- friability in comparison with the metal;
- low fire.
The main types of plastic ducts
According to the type of plastic section of the ventilation ducts are:
- rectangular;
- square;
- round.
Round air ducts are suitable for the installation of long air lines. They are not very suitable for small kitchens - are bulky and highly distinguished in the interior. However, the capacity of their best, they are almost noiseless and easy to install.
Diameter circular vent pipe is 80 mm - 150 mm. Length is 500 mm, 1000 mm, 1500 mm. The larger the diameter of the duct, the more air through it can skip itself. For example, a 100 mm pipe has a sectional dimension bandwidth 300 m3 /час. Bandwidth ducts shown in the table.
Plastic air ducts of a rectangular or square shapes are more compact in size. Flat ventilation circuit can be easily attached with special holders to the walls and ceiling. Flat and square box can be hidden in the closet or under the ceiling. Assembling the elements does not require the presence of experts. For the installation of ventilation required track tees and flanges.
On sale there are the following dimensions of the ventilation rectangular plastic pipes for exhaust equipment:
- width - 110 mm, 122 mm, 204 mm;
- height flat ventilation pipe - 55 mm, 60 mm;
- length - 350 mm, 500 mm, 1000 mm, 1500 mm, 2000 mm and 2500 mm;
- wall thickness of from 2 to 8 mm.
The wall thickness depends on the size of the cross section - the larger cross section, the thicker wall.
Round and rectangular exhaust pipes are:
- tough;
- Flexible.
In hard - thick walls, so they do not lose their shape over time.
In rigid pipes smooth inner surface, there are no drops and bumps. The air flow moves through it quickly and quietly. On smooth walls inside will build up a deposit - this will facilitate the care of the exhaust system.
Flexible plastic tubes are corrugated, which during assembly can be stretched, bent at any angle.
Corrugated pipe is used where there is no technical possibility to lay rigid boxes. The length of one such duct is up to 2.5 meters. Their installation does not require a large number of fixtures. Disadvantages are the same as that of the flat plastic - instability to high temperatures.
Plastic corrugated pipe for exhaust is rarely used, preference is given basically similar smooth metal structure. Channels of corrugated pipes emit higher noise of the ventilation.
Calculation of the cross section of plastic ducts
Each model has exhaust pipe with a certain cross-section, so round ducts should be selected under this size. When mounting boxes requires the calculation of plane sectional area of a circular pipe.
If the diameter is drawn at 110 mm, the area is calculated by the formula:
S = πD² / 4 = 3.14 x 0,11²: 4 = 0.01 m²
flat tube size with sides of 80mm * 125mm is equal to 0.01 m2. Obtained by replacing circular duct with a diameter of 110 mm. You can install a larger, but less impossible. This will lead to a decrease in overall system performance.
The diameter of the hood outlet is at the original size selection ventilation plastic pipes. Also take into account the capacity of the hood and duct length. The long and winding road, the lower the performance of the entire system. Optimal - one rotation during the transition from the hood on a horizontal portion.
The correct calculation of the cross section of plastic ducts to ensure the efficiency of extraction equipment and optimum ventilation in the room.
Attention! If there is no confidence in the correctness of independent calculations - it is necessary to turn to professionals. Engineer Service Payment times cheaper than the cost of correcting any deficiencies.
After calculating the results need to be sure to double-check and only then make a decision about buying and attempting to install.
What equipment is used for mounting
To attach the ventilation of the plastic pipes to draw their own hands will be required:
- tube of rectangular or circular cross section;
- Lugs of the same diameter with the outlet of the hood;
- coupling the corresponding diameter fittings;
- ventilation grille;
- silicone sealant.
assembly rules
Corrugated ducts very easy to install. Cutting is performed without the use of such fittings, with any bends. Corrugated stretched well, so one segment may be enough for the whole route.
To exhaust pipe corrugation is secured with a plastic clip. No more fasteners is not required. Likewise the other end is attached to a side of the ventilation grille. The grille is screwed on the screws to the exhaust hole in the wall.
Ducts PVC hacksaw cut into segments of the desired size.
Round and flat plastic ducts require additional elements for the connection between a network and when cornering. For their compounds are used double-sided sleeve round or rectangular cross-section. Clutch diameter slightly larger diameter of the pipe, so it can be easily inserted into it. For sealing the junction structure are processed with silicone sealant.
For flat airbox more attached fitting. Since drawing a round tube, it can not be directly installed rectangular box. Here, special adapter is used, one side of which a circular opening for planting, and with another rectangular. fitting size is selected according to the magnitude of the duct.
In certain cases, for the connection of ventilation pipes, exhaust hood is required dismantling it. Then the entire structure assembly set in place.
Recommendation of experienced craftsmen
For efficient operation of the duct during installation must comply with the following rules:
- observe pipe diameters and the air vent;
- not exceed the length of the structure - 3 meters;
- not do more than three bends and elbows;
- try to avoid angles of 90 degrees;
- take into account the direction of air flow - from the bell to the thin end of the pipe.
Ducts of polymers are gaining popularity gradually displacing steel counterparts. For efficient operation of the ventilation system in the kitchen you need to select the appropriate option. Proper installation of the pipe will provide a long operation of the equipment.
