• Homogeneous air distribution and temperature

  • Air distribution with low energy consumption

  • Efficient air distribution in your greenhouse

  • Specific air solutions for your specific project




A good air distribution duct will determine a homogenous climate in your greenhouse. It goes further than just selling a hose with little holes. At KE GrowAir it is all about dialogue, expertise and reliability. We don’t have a standard duct, components or end-products in stock, it will be customised and made for you.

GrowAir ducts create a homogenous air distribution for cooling, heating and ventilating. A patented outlet pattern provides a more homogenous climate in your greenhouse with the result that the horizontal and vertical temperature gradient becomes smaller compared to other air distribution systems. A more homogenous climate ensures a more uniform growth pattern of your product, enabling more production in the entire greenhouse.

Why choose a GrowAir duct system?

1. Flexible and customised solutions
Solutions specifically customised to your project and designed to ensure optimal air distribution

2. Efficient air distribution
The system has a high inductive outlet pattern that provides a good mixture of the injected air with the air that is already in the greenhouse.
Due to the position and our hole pattern, you obtain a lower temperature in the crop of the plant

3. Unique design
With this specifically developed duct for greenhouses we have found the right balance between the dynamic and static pressure.
This is why the air flow at the beginning and at the end of the duct is more uniform than in any other system

4. Patent
The duct system has a uniquely designed, patented and highly inductive outlet pattern. This unique outlet pattern ensures a very good
mixture of the injected air with the air that is already between the leaves and in the greenhouse

5. Entrainment
Entrainment is an undesired parallel airflow along the air distribution duct in the direction of the airflow, which is usually created in air
distribution ducts with only a normal hole pattern. Entrainment is a major cause of poor air distribution in greenhouses. Due to the slanted
outlet, there are high air speeds and a shortage of air at the beginning of the air distribution duct and an excess of air at the end

6. Less energy consumption
Due to the single duct concept and a balanced ratio between the selected ventilator and the air distribution duct, the power consumption of
the ventilator is considerably less, resulting in lower energy consumption or a larger quantity of air supply

7. UV-stabilised
The material is transparent or white polyethylene (PE) and is UV-stabilised [320 Kilo Langley per Year (KLY); 80 KLY is one year of UV in
the Netherlands]. The thickness of the material is 150 or 180 micron. It is produced in three layers, resulting in a material that can optimally
withstand cracking (breaking by continuous movements)

8. Easy to mount
An additional advantage of a single hose is the easy mounting: you have to mount only a single duct and that will save you time. You don’t
have to consider the second duct which will be inside the outer duct that can move with the installation. The weight is many times lower so
that you can install a lighter suspension construction. When replacing the ducts, you have to pay only half the amount of environmental tax
for transporting the discarded plastic

The GrowAir® solution is based on a patented system designed with holes in combination with flow controlling direction baffles. This will reduce the air flowing along the textile duct and ensure a uniform air distribution.

Patented Diffusion Holes


More even air distribution in the length and height of the duct

Lower overall pressure loss 

Takes less time to install due to the GrowAir® duct patented pattern system, only requires one duct

The patented pattern in the GrowAir® system will be made in such a way that the entrainment problem seen on the Double Duct system will be balanced more out

Normal holes

More uneven air distribution in the length and height of the duct

Higher overall pressure loss due to the Double Duct system

Takes longer time to install due to the Double Duct system

Entrainment may occur in the first part of the system, leading to less air in the area where the ducts are connected to the fan

Temperature in the crop of the plant

There is a temperature difference in the crop of the plants during the day. In this pilot we have measured a difference of 6°C between the Double Duct and the GrowAir® duct

At night the temperature and humidity is more uniform (1°C)

See a large image

Horizontal Temperature Gradient

The GrowAir® duct has over 120 metres a horizontal temperature difference of 1°C at the bottom and 2.5°C at the top of the plants

The Double Duct has a horizontal temperature difference of 6°C at the bottom and 4.5°C at the top of the plants over 120 metres

See a large image

Pressure loss

Due to the construction method of the GrowAir® duct system there is a higher static pressure available to force the air out of the holes. This has a significant influence on the air velocity and the potential possible reachable height for the air leaving the ducts

In this project the static pressure in the Double Duct after 65 m is 47 Pa at 70% Fan Speed, which is much lower than the GrowAir® system that has a static pressure left of 85 Pa at 65 metres at 70%

See a large image

Temperature in the duct

The temperature in the duct is equal for GrowAir® and Double Ducts, there is absolutely no isolation activity from the two polyethylene ducts that makes a double duct

See a large image

Vertical Farming

The growing world population and accompanying urbanization makes it necessary to come up with solutions which put less stress on arable soils in the world. Vertical Farming holds the key. In this fast growing market many companies look at LED light regimes for growth and hydroponic systems for optimal produce. One key feature in these systems is undervalued: an optimal homogenous air distribution. And this is where we are experts in. To distribute air looks very simple and easy, but it’s a very complicated business, mistakes are easily made. With our 30 years of knowledge we know how to distribute air best. 


For Vertical Farming we combine the strengths of KE Fibertec and KE GrowAir to benefit you with:


* Flexible and customized optimal solutions

* Horticultural and optimal air distribution knowledge combined

* Homogenous air distribution in every corner, at every level of your vertical farm

* Fire approved materials

* Easy to transport and install

* Hygienic/Food grade and easy to maintain

* Sustainable ventilation

Different types of air distribution systems and fabrics

Because no project is alike, we choose for every project the best combination of air distribution system and fabric to meet your demands for the project. This ensures you to get the best homogenous air distribution there is for optimal produce in the market.

Currently there are five air distribution systems available to use in vertical farms:


The KE-Low Impulse System is produced using round ducts (Ø), half-round (D)
or quarter round (½D) ducts. The air distribution principle for horizontal low impulse
systems is based on passive thermal displacement where the air is supplied at a lower
temperature in relation to the air in the room. 


The KE-Inject® System is produced in the form of round (Ø), half-round (D)
or quarter-round (½D)
 ducts and is made of a coated, non permeable textile
material with groups of small holes in the
 duct surface. From a ventilation
technology perspective, the KE
 Inject System can be regarded as an active
 impulse system for mixing ventilation. The KE-Inject System, unlike
its low impulse
 counterpart, can be used for cooling, ventilation and heating. 


The KE-DireJet® System is produced in the form of round (Ø), half-round (D)
or quarter round (½D) ducts and is made of a coated, non-permeable textile
material with rows of conical nozzles for 100% active and directional delivery. 
From a ventilation technology perspective, the KE-DireJet System can be regarded
as an active high impulse system for mixing ventilation. 
KE Fibertec is the only
distributor of textile ducts
 that offers five different nozzle sizes: Ø12, Ø18, Ø24,
Ø48 and Ø60 mm.


The KE-Inject® Hybrid System is produced in the form of round (Ø), half-round (D)
or quarter-round (½D) ducts and is made of a permeable textile material with groups
of small lasercut holes in the duct surface. The lasercut holes are placed in the same
patented hole design as with the KE-Inject System. From a ventilation technology
perspective, the KE-Inject Hybrid System can be regarded as a combination of
high impulse ventilation and passive low impulse ventilation.


The KE-DireJet® Hybrid System is produced in the form of round (Ø), half-round (D)
or quarter-round (½D) ducts and is made of a permeable textile material with rows of
conical nozzles for  partially active and directional delivery. 
From a ventilation technology
perspective, the
 KE-DireJet Hybrid System can be regarded as a combination of active high
impulse ventilation
 and passive low impulse ventilation. In a nutshell, the KE-DireJet Hybrid
 comprise low impulse ducts which are madeactive by using conical nozzles.


Furthermore there are 3 types of fabrics available to come up with the best solution for your project:

o GreenWeave® (with 7 permeability's)
o MultiWeave® ( with 5 permeability's)
o ZeroWeave® (with PVC Coating)

Finally all our solutions for an optimal homogenous air distribution will come with:

o Food grade and fire approved materials
o One of the 1600 RAL/Pantone colors
o Cradle2Cradle materials

KE GrowAir

GrowAir is an enterprise that specialises in air distribution systems for the horticultural sector by producing polyethylene (PE) air distribution ducts. We – together with our 35 employees and more than 30 years of experience in designing, advising and supplying air distribution systems – provide a specific solution for your specific project.

Why choose our air ducts?
No matter how much energy we spend on a good solution, it requires dialogue about the expectations for the end result. We provide advice free of charge, regardless of the scope of the project, and make all the calculations based on our experience and by means of our unique WinVent calculation software. Our experienced sales engineers are extensively trained in the area of ventilation products and are there to advise and support you. Good cooperation is based on trust and we hope to get the opportunity to translate our words into deeds with your next ventilation order. 

See the video and be inspired!


Installation manual
Sun load overview
Terms of delivery


KE Group

KE GrowAir is owned by KE Fibertec Benelux, based in Strijen, the Netherlands and is part of the KE Fibertec Group, world leader in textile based ventilation systems.

KE Fibertec develops, manufactures and markets "Good indoor climate" or air distribution systems based on fibre technology. The principle is to create draft free and uniform distribution of the ventilation air through our tailored textile ducts. Textile air distribution systems are used in almost all applications - from industry to sports centres, office facilities, laboratories, food industry, schools and many other applications that require a good indoor climate. Textile air distribution systems can be applied in all ventilation, air-conditioning, cooling or heating projects.

The foundation of KE Fibertec goes back to 1963 when Keld Ellentoft (KE) began manufacturing filterbags for industry. Today, the KE Fibertec Group is composed of six sales subsidiaries in the Benelux, UK, Germany, Turkey, USA and in Denmark. Further, the group holds two production facilities in Denmark and in the Czech Republic.

The people of KE Fibertec know how to move air in a way that you don’t feel any draft. This is "Air the way you want".


KE GrowAir B.V. 
Edisonweg 11 
3291 CK Strijen
Po box 5802
3290 AC Strijen

Tel. +31 (0) 78 674 8475
Fax +31 (0) 78 674 8476

Chamber of commerce: No: 59448113
VAT no: NL 853492116B01 
Bank: ING: NL71INGB0006325664