It often happens, especially in winter, that we notice annoying drafts of cold air or perceive unpleasant odors rising from the kitchen extractor hood.

These inconveniences not only compromise the comfort of your home, but can also negatively affect the energy efficiency and hygiene of your kitchen.

If you find yourself in this situation, it is likely that you need a non-return valve for your extractor hood.

In this article, I will give you some useful tips for installing non-return valves, but not before explaining their importance and how they work. Knowledge is very important!

What are non-return valve? What they are used for? How they work?

Non-return valves, also known as backdraft dampers, are devices installed in kitchen extractor hoods to prevent air from flowing back and to keep cold air or bad odors from re-entering the kitchen. When the extractor hood is off, the valve automatically closes, helping to maintain a comfortable and hygienic environment.

In general, non-return valves are universal, with some rare exceptions, and have a "butterfly" design (as shown in the photo), which closes the exhaust duct when the hood is off, preventing air or unpleasant odors from entering the kitchen.

The elements that differentiate non-return valves are:

  • Diameter size
  • Materials

I will explain these two points in more detail in the section dedicated to choosing the right valve.

"Butterfly" non return valve installation

Are they always installed in hoods?

Non-return valves are NOT usually installed in kitchen hoods. However, they become essential in all situations where cold air re-enters the kitchen from the chimney or when the hood is connected to a shared flue with other residences, as in the case of apartment buildings, because fumes from other units could circulate back into your kitchen.

Benefits of non-return valves

Installing these valves provides numerous advantages:

  • Energy efficiency: By preventing cold air from entering the kitchen, they reduce the need to heat the space, helping to lower heating costs.
  • Comfort: They eliminate the entry of bad odors and cold air, improving comfort in the kitchen.
  • Hygiene: They keep the kitchen cleaner by preventing the backflow of contaminated air.

Guide to choosing the valve

Are there factors that determine the choice of one valve over another? If so, what are they?

Remember to consider these factors when choosing:

  • Size: The size of the valves must be compatible with the diameter of the exhaust duct. Common sizes are 12 cm and 15 cm.
  • Materials: Valves can be made of plastic or metal. The material does not affect their functionality, but it could impact their durability over time.
  • Compatibility: Most valves are universal and compatible with most extractor hoods. Sometimes, there are original valves specific to certain brands.

If, after evaluating these factors, you find that you need non-standard sized non-return valves, look for them on Filtro Cappa, and if you don't find the valve that suits you, contact me. I will help you find it.

Installation and maintenance

Basic DIY installation guide:

If you want to install the non-return valve yourself, here is a basic guide:

  1. Turn off the extractor hood and disconnect it from the power supply.
  2. Dismantle the exhaust duct.
  3. Insert the valve into the duct, ensuring that the flaps open towards the outlet and not towards the hood.
  4. Reassemble the duct and check the tightness of the connections.

Although DIY installation is possible, I recommend contacting a specialized technician who can ensure the correct installation and functioning of the valve. A valve positioned incorrectly could nullify your efforts and not solve the problem of air and bad odors re-entering the environment.

How to know if the non-return valve is working?

A sign that the non-return valve is working correctly is the absence of unpleasant odors or cold air coming from the hood during the winter. Regular checks and proper maintenance ensure that the valve continues to function optimally.