Check out the most frequently asked questions


How do I place an order?

You can place an order after registering at Then, after logging in, add the products to the shopping cart and pay for the order as indicated on the page.

Is it possible to pick up in person?

Yes, it is possible to pick up in person, but only goods that have been pre-ordered and paid for. After completing the order, we send a text message and an email to inform you that you can pick up the goods. Warehouse address ul. Graniczna 46, 32-765 Krzeczów.

How do I pay for my order?

You can pay for your order using Przelewy24 or traditional bank transfer. The only form of payment is prepayment. Cash payment is not available.

How much does transportation cost?

The shipping costs are determined at the time of order fulfillment in the shopping cart. The cost depends on the size and weight of the shipment.

Can I change my private account to a business account?

Yes, you can. After logging in to your account, you should go to the “Business Account” tab and click on “Change Account to Business” and fill out the registration form.

Where can I find the nearest installer?

On our website, you can see companies specializing in the installation of ventilation systems.

Will I be notified about the shipment?

Yes, on the day of shipment, when the goods are ready for dispatch, you will receive a text message and an email with the shipping number and the scheduled delivery date.

What is the difference between PEFLEX STANDARD and PEFLEX SPECTRA 1000 duct?

The main difference lies in the biocidal effectiveness of the internal layer of the duct in terms of protection against fungi and bacteria. For the standard version, it reaches up to 60%, while for the SPECTRA 1000 variant, it reaches up to 98%.

Intake/exhaust grille - why is there no mesh in the grilles or the mesh is with large windows?

Dirt settles on the fine-mesh mesh, blocking airflow. Contaminants from outside will be caught by the filters, which are easy to clean or replace. Cleaning the net at high altitudes is difficult and expensive. Another important feature of the air intake/exhaust grille is the “drip or drop edge” to protect the wall from dirt stains.

Does the EPS duct on the intake and exhaust need to be additionally insulated? if so, then with what ?

  • EPS in the attic where the temperature is below zero
  • EPS in the boiler room where it is +21 degrees

How does BOX-MAKER work?

The operation of BOX-MAKER is described at the following address –

What needs to be prepared at the recuperator installation site?

At the installation site, prepare the sewage approach, electrical outlet, 4×0.5 shielded cable, above the length of 10 m recommended 4×0.75 (shielded) – optional for recuperators on Wi-Fi.

What diameter should the intake and exhaust be?

The intake and exhaust should be at least 1-2 diameters larger than the duct coming out of the recuperator. If the duct coming out of the recuperator has a diameter of 200 mm, then the intake and exhaust should ideally be of diameter 250 mm or 315 mm.

How to plan the thickness of polystyrene foam on the ceiling or the amount of space in the false ceiling ?

For an installation based on a duct system with a diameter of fi 75 mm on the ceiling (in the insulation layer), it is recommended to use polystyrene with a thickness of 10 cm. If it is not possible to use polystyrene , ducts with a diameter of fi 50 mm should be used instead. When laying ventilation ducts under the ceiling, a space of approximately 10 cm thick (measured from the ceiling to the frame of plasterboard) should be provided to hide the installation elements.

What diameter should the openings in the ceiling be for fi125 air diffusers?

If we are before pouring the ceiling, in order to avoid drilling at a later stage, sewer pipes with an outside diameter of fi160 can be used at an early stage in the positions of the air diffusers.

What diameter holes should be made for air diffusers and distribution boxes couplers in an existing ceiling?

If we already have a completed ceiling, we should drill holes with a diameter of 132mm for air diffusers with a diameter of 125mm. For fi200 spigots, it would be best if the hole in the ceiling had a diameter of 250mm. For fi160mm spigots, it is best to make fi200 diameter holes.

What is the difference between socket and nipple expansion boxes?

The boxes differ in the diameter of the connection spigot. The socket box is designed for direct connection of air diffusers and it comes in diameters of 100, 125,160. While the nipple box is designed for extension which overlaps the nipple and comes in diameters of 98,123,158.

How to plan space for a recuperator ?

To avoid creating additional resistance for the recuperator, it’s important to plan the space for the intake and exhaust ducts carefully. Allow for a minimum of 30 cm straight section for the extract and supply ducts, and a minimum of 50 cm straight section for the intake and exhaust ducts.

Nails from the underfloor have pierced the ventilation ducts - what to do in such a case?

If the damage is extensive, it is best to cut out the damaged piece and use connectors dedicated to ventilation ducts to insert new, undamaged sections. Typically, damages are minor, and accessing the ducts in spread-out loops under the underfloor heating can be challenging. In such a case, it’s necessary to remove the pins. While removing the pins, the damaged material will partially return to its original position, and the resulting hole can be sealed using dense polymer glue and mounting tape. Care must be taken to ensure that the adhesive or other sealant does not get inside the duct and cause airflow restrictions.

What size openings should I prepare in the ceiling?

The size openings in the ceiling depends on the diameter of the spigot of the plenum and distribution box. The selected diameters for the duct connections are specified and described in the prepared project. It is safe to make a hole 1-2 cm larger than the diameter of the duct.

How to properly soundproof the installation and the recuperator?

To ensure a quiet ventilation system, we recommend installing insulated PEFLEX Premium flexible ducts, each measuring 2-3 meters, on the supply and exhaust sections. Alternatively, dedicated rigid or flexible silencers can also be used.

What is the recommended distance of air diffusers from walls/windows?

We recommend installing air diffusers 0.6 -1 meter from walls/windows.

What length should the sections of ventilation ducts with a diameter of 75 mm be?

The minimum length of individual sections between the manifold and the plenum box should be about 4 meters (shorter sections may cause problems with adjusting the airflow). For long sections, above 12-14 meters, it’s necessary to increase the number of ducts leading to the plenum box to achieve the desired airflow. Whenever possible, it’s advisable to avoid significant disparities in the lengths of ventilation duct sections to individual rooms, or to take this into account when designing the installation. We recommend having the ventilation system designed by an experienced designer or installer. You can purchase ventilation design projects at

How do I order a project?

You can place your order directly in our online store at

Where should I send the documents to proceed with the project?

Please send your documents to

What is needed to prepare a ventilation project?

Once you have purchased the project, you should send:
1. Floor plans of all building levels with the proposed changes marked on the project.
2. Cross-sections A-A and B-B.
3. Roof truss plan.
4. Completed questionnaire form for the project.


Please send the files in DWG, JPG or PDF format. The maximum size of attachments is 25 MB.

What does the prepared ventilation project include?

The project includes a technical description, drawings illustrating the layout of the installation, and a material cost estimate.

I would like to order a project from you. What is the lead time for completing the project?

The lead time for completing the project is typically around 7 business days.

Current information about the lead time is available on our price list: After placing an order, the designer will inform you about the assigned project preparation deadline.

Express projects with the lead time of up to 2 business days are also available.

I have received a draft. How can I now place an order for the quoted material?

Along with the project, you will receive a link to a pre-filled shopping cart on the website via email. This way, you’ll be able to install mechanical ventilation in your home on your own!

Do you do ventilation projects based on a system other than PEFLEX?

We exclusively offer mechanical ventilation design based on the use of PEFLEX system.

Are there projects available for commercial premises?

Projects with approvals from fire services, sanitary inspection, occupational health and safety (e.g., for commercial buildings) are not available through our company.

Can I add such a project to the documents for a building permit?

Certainly! Please visit our website, where you can order a project with a stamp in the construction proceedings.

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