Plastic ventilation pipes for hoods: technical specifications and installation


The cor­rect choice of air ducts is essen­tial for effi­cient oper­a­tion of the kitchen hood. With the advent of plas­tic pipes on the con­struc­tion mar­ket, it has become cheap­er and eas­i­er to install ven­ti­la­tion com­mu­ni­ca­tions. Plas­tic ven­ti­la­tion pipes have become an afford­able alter­na­tive to gal­va­nized exhaust ducts.

Vari­ety of plas­tic air ducts

Specifications and properties

For the man­u­fac­ture of plas­tic air ducts, 4 types of poly­mers are used: poly­eth­yl­ene, polypropy­lene, polyvinyl chlo­ride (PVC), flu­o­ro­plas­tic (PVDF). Con­sid­er the char­ac­ter­is­tics of each type.

Poly­eth­yl­ene plas­tic air ducts are used main­ly in coun­try hous­es with sea­son­al res­i­dence. They are UV pro­tect­ed and anti­sta­t­ic. Poly­eth­yl­ene is resis­tant to tem­per­a­ture extremes, it can be used both out­side and indoors. Safe oper­a­tion of poly­eth­yl­ene pipes is guar­an­teed in the range from — 45C to + 75C.

Polypropy­lene ducts are used to con­nect the hood due to their low cost and ease of instal­la­tion. Polypropy­lene is a good dielec­tric, resis­tant to aggres­sive envi­ron­ments, but does not with­stand low tem­per­a­tures, there­fore it is used only in a warm room.

Impor­tant! If the tem­per­a­ture norm + 85С is exceed­ed, the mate­r­i­al is com­bustible and melts eas­i­ly. You can find vari­eties with fire-resis­tant com­po­nents.


The main qual­i­ties of their PVC ven­ti­la­tion ducts are light­ness, struc­tur­al strength and inex­pen­sive price. The tem­per­a­ture range for effi­cient oper­a­tion is from 0C to 80C, tem­per­a­tures below zero are not tol­er­at­ed. Heat­ing above +120C is haz­ardous to health, the prod­uct will begin to release chlo­rine. PVC pipes are active­ly used when installing the hood, if the tem­per­a­ture dur­ing use does not exceed the rec­om­mend­ed thresh­old.

PTFE ven­ti­la­tion ducts are durable and resis­tant to aggres­sive envi­ron­ments. They are able to with­stand acid-base vapors, there­fore they are main­ly used for ven­ti­lat­ing aggres­sive air flow in pro­duc­tion. Safe oper­a­tion tem­per­a­ture from ‑40С to +140С. Due to the high cost and increased gas per­me­abil­i­ty of the mate­r­i­al, they are rarely used in an apart­ment.

Advantages and disadvantages of plastic ventilation pipes

Plas­tic air ducts have the fol­low­ing advan­tages:

  • light weight;
  • com­plete tight­ness;
  • low noise lev­el;
  • fin­ished appear­ance that does not require paint­ing;
  • ease of instal­la­tion;
  • resis­tance to cor­ro­sion;
  • tox­ic safe­ty;
  • pro­duce min­i­mal sta­t­ic resis­tance to air­flow;
  • eas­i­ly dis­man­tled for instal­la­tion in anoth­er ver­sion;
  • anti­sta­t­ic treat­ment pre­vents dust from set­tling inside the sys­tem.


  • brit­tle­ness in com­par­i­son with met­al;
  • low fire resis­tance.

The main types of plastic air ducts

Accord­ing to the type of sec­tion, plas­tic ven­ti­la­tion ducts are:

  • rec­tan­gu­lar;
  • square;
  • round.
Round plas­tic pipes for con­nect­ing the hood


Round ducts are suit­able for instal­la­tion of long ven­ti­la­tion ducts. They are not very con­ve­nient for small kitchens — they take up a lot of space and stand out strong­ly in the inte­ri­or. How­ev­er, their through­put is bet­ter, they are almost silent and easy to install.

The diam­e­ter of the round ven­ti­la­tion pipe is 80 mm — 150 mm. The length is 500mm, 1000mm, 1500mm. The larg­er the diam­e­ter of the duct, the more air it can pass through itself. For exam­ple, a pipe with a cross sec­tion of 100 mm has a capac­i­ty of 300 m3 /hour. The capac­i­ty of the air ducts is indi­cat­ed in the table.

Capac­i­ty table for plas­tic air ducts

Rec­tan­gu­lar or square plas­tic air ducts are more com­pact in size. The flat ven­ti­la­tion route is eas­i­ly attached to the walls and ceil­ing with spe­cial hold­ers. Flat and square box­es can be hid­den in a clos­et or under a false ceil­ing. The assem­bly of ele­ments does not require the pres­ence of spe­cial­ists. Tees and flanges are required for mount­ing the ven­ti­la­tion duct.

Plas­tic rec­tan­gu­lar ducts for the hood in the apart­ment


On sale there are the fol­low­ing sizes of ven­ti­la­tion rec­tan­gu­lar plas­tic pipes for exhaust equip­ment:

  • prod­uct width — 110 mm, 122 mm, 204 mm;
  • flat ven­ti­la­tion pipe height — 55 mm, 60 mm;
  • length — 350 mm, 500 mm, 1000 mm, 1500 mm, 2000 mm and 2500 mm;
  • wall thick­ness from 2 to 8 mm.

The thick­ness of the walls depends on the size of the sec­tion — the larg­er the sec­tion, the thick­er the walls.

Round and rec­tan­gu­lar exhaust pipes are:

  • hard;
  • flex­i­ble.

Rigid ones have thick walls, so over time they will not lose their shape.

Rigid air ducts in the inte­ri­or

Rigid pipes have a smooth inner sur­face, there are no drops and bulges. The air flow moves through them quick­ly and silent­ly. Soot will not accu­mu­late on the smooth walls inside — this will facil­i­tate the main­te­nance of the exhaust sys­tem.

Flex­i­ble plas­tic pipes are cor­ru­gat­ed, which dur­ing instal­la­tion can stretch, bend at any angle.

Plas­tic cor­ru­ga­tion for ven­ti­la­tion sys­tems


Cor­ru­gat­ed pipe is used where there is no tech­ni­cal pos­si­bil­i­ty to lay rigid box­es. The length of one such air duct is up to 2.5 meters. Their instal­la­tion does not require a large num­ber of fas­ten­ers. The dis­ad­van­tages are the same as those of flat plas­tic ones — insta­bil­i­ty to high tem­per­a­tures.

A plas­tic cor­ru­gat­ed pipe for exhaust is rarely used, main­ly a sim­i­lar smooth met­al con­struc­tion is pre­ferred. Chan­nels made of cor­ru­gat­ed pipes emit increased noise dur­ing ven­ti­la­tion.

Calculation of the section of plastic air ducts

Each hood mod­el has a branch pipe with a cer­tain cross sec­tion, so round ducts must be select­ed for this size. When installing flat ducts, it is nec­es­sary to cal­cu­late the cross-sec­tion­al area of ​​​​a round pipe.

If the diam­e­ter on the hood is 110 mm, the area is cal­cu­lat­ed using the for­mu­la:

S=πD²/4= 3.14 x 0.11²: 4 = 0.01 m²

The area of ​​a flat pipe with sides 125mm * 80mm will be equal to 0.01 m2. It turns out the replace­ment of a round duct with a diam­e­ter of 110 mm. You can set a larg­er size, but not a small­er one. This will degrade the per­for­mance of the entire sys­tem.

The diam­e­ter of the out­let of the hood serves as the ini­tial size when choos­ing ven­ti­la­tion plas­tic pipes. Also take into account the pow­er of the hood and the length of the duct. The longer and more wind­ing the track, the low­er the per­for­mance of the entire sys­tem. The best option is one turn when mov­ing from the hood to the hor­i­zon­tal sec­tion.

The cor­rect cal­cu­la­tion of the sec­tion of plas­tic air ducts for the hood will ensure the effi­cien­cy of the equip­ment and opti­mal air exchange in the room.

Atten­tion! If there is no con­fi­dence in the cor­rect­ness of inde­pen­dent cal­cu­la­tions, you need to turn to pro­fes­sion­als. Pay­ment for the ser­vices of an engi­neer is some­times cheap­er than the cost of cor­rect­ing the defects that have arisen.

After the cal­cu­la­tion, it is nec­es­sary to dou­ble-check the result and only after that make a pur­chase deci­sion and pro­ceed with instal­la­tion.

What equipment is used for installation


To con­nect ven­ti­la­tion from plas­tic pipes to the hood with your own hands, you will need:

  • pipes of rec­tan­gu­lar or round sec­tion;
  • clamps of the same diam­e­ter with an exhaust out­let;
  • cou­plings, fit­tings of the appro­pri­ate diam­e­ter;
  • ven­ti­la­tion grille;
  • sil­i­cone sealant.

Installation rules

Cor­ru­gat­ed ducts are the most con­ve­nient to install. Inser­tion of such is car­ried out with­out the use of fit­tings, with any bends. The cor­ru­gat­ed pipe stretch­es well, so one piece can be enough for the entire route.

The cor­ru­ga­tion is attached to the exhaust pipe with a plas­tic clamp. No more fas­ten­ers are need­ed. In the same way, the oth­er end is attached to the sides of the ven­ti­la­tion grill. The grate is screwed onto the screws to the exhaust hole in the wall.

PVC air ducts are cut with a hack­saw into sec­tions of the desired size.

Hack­saw for met­al eas­i­ly copes with plas­tic

Round and flat plas­tic ducts require addi­tion­al ele­ments for con­nec­tion between each oth­er and when turn­ing the net­work. For their con­nec­tion, dou­ble-sided cou­plings of round or rec­tan­gu­lar sec­tion are used. The diam­e­ter of the cou­pling is slight­ly larg­er than the diam­e­ter of the pipe, so it can be eas­i­ly insert­ed into it. For tight­ness of the struc­ture, the joints are treat­ed with sil­i­cone sealant.

A fit­ting is also attached to the flat ven­ti­la­tion ducts. Since the branch pipe in the hood is round, it is impos­si­ble to imme­di­ate­ly install a rec­tan­gu­lar box into it. A spe­cial adapter is used here, on one side of which there is a round hole for land­ing, and on the oth­er, a rec­tan­gu­lar one. The size of the fit­ting is select­ed accord­ing to the size of the duct.

In cer­tain cas­es, to con­nect the ven­ti­la­tion pipes to the hood, it is required to dis­man­tle it. Then the entire assem­bly is installed in place.

Recommendations from experienced craftsmen

For effi­cient oper­a­tion of air ducts dur­ing instal­la­tion, the fol­low­ing rules must be observed:

  • observe the diam­e­ters of the pipe and the ven­ti­la­tion hole;
  • do not exceed the length of the struc­ture — 3 meters;
  • do not make more than three bends and knees;
  • try to avoid 90 degree angles;
  • take into account the direc­tion of move­ment of the air flow — from the sock­et to the thin end of the pipe.
Cor­rect air­flow direc­tion

Air ducts made of poly­mers are gain­ing pop­u­lar­i­ty, grad­u­al­ly replac­ing steel coun­ter­parts. For the effi­cient oper­a­tion of the ven­ti­la­tion sys­tem in the kitchen, it is nec­es­sary to choose the appro­pri­ate option. Prop­er instal­la­tion of pipes will ensure long-term oper­a­tion of the equip­ment.


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