
An air compensation valve, or a window replacement air valve, also known as a frame valve, is one of the most effective and simplest ways to improve indoor air quality in buildings where ventilation is based on gravity or mechanical exhaust ventilation . This guide explains everything about why and how replacement air valves are critical to optimizing indoor air quality.
What exactly is a replacement air valve?
This is not a luxury product, but a necessity if you want your home to breathe properly. A replacement air valve is, in its simplicity, a ventilation component that brings in controlled, filtered fresh outdoor air indoors. When you remove air, it must be replaced with new air, and not just any air – but clean, draft-free air.
Why do you need a replacement air valve for a window?
The principle of ventilation is simple: if air can’t get in, it can’t get out. This means that indoor emissions, such as VOCs (volatile organic compounds), carbon dioxide and moisture, are left to circulate in the room air. The end result? Indoor air quality deteriorates significantly.
Effects of poor indoor air quality:
Respiratory infections and health problems : High levels of VOCs and carbon dioxide can cause fatigue, headaches, and breathing difficulties.
Mold problems : If moisture is not removed, it condenses in structures and creates favorable conditions for mold growth.
Decreased living comfort : Stinky air, unpleasant odors and drafts reduce the comfort of the space.
The replacement air valve ensures that the air circulates as it should. By allowing outside air to enter in a controlled manner, exhaust ventilation can effectively remove pollutants and excess moisture, significantly improving indoor air quality.
The biggest pitfall of window renovation
I want to highlight something that is too often forgotten when it comes to window renovations: ventilation. It’s tempting to focus solely on energy savings and tight windows – and of course energy efficiency is important – but if you don’t consider ventilation, you’re doing your house a disservice.
In old houses, ventilation was often a straightforward system: leaky windows. Yes, it sounds simple, but it worked. Air moved in naturally through small cracks and unsealed seams, and out through, for example, a fireplace chimney or exhaust ducts. When you replace these leaky windows with modern, fully sealed windows without a replacement air valve, the whole balance is thrown off. And guess what happens next?
End result: A vicious cycle of indoor air problems
Air cannot move : The exhaust ventilation does not work because there is no replacement air coming from outside.
Moisture stays inside : Moisture in the indoor air begins to condense on the structures.
Mold problems : When moisture is not removed, mold soon finds its way into structures.
Respiratory problems : Indoor air quality is rapidly deteriorating, VOCs, carbon dioxide and humidity are starting to affect living comfort and health.
And at this point, you find yourself in a situation where energy-saving windows pay for themselves in the form of expensive repair costs. Mold repairs, structural replacements, and retrofits of improved ventilation are much more expensive than adding replacement air valves during the design phase.
Why do replacement air valves solve the problem?
Replacement air valves allow controlled and filtered outdoor air to flow in. When there is enough replacement air coming in from outside, the exhaust ventilation works as it should, and indoor humidity, carbon dioxide and pollutants are removed from the building. This small addition can save you from huge problems.
What to do before window renovation?
Check the current ventilation : Is it working well? How does the replacement air come in?
Design replacement air vents : These can be installed in window frames at the factory or added later, but they are not an optional accessory – they are a necessity.
Ask an expert : A professional can assess the state of your home's ventilation and help you design a system that will work in the long term.
Energy efficiency without compromise
A well-planned window renovation that takes into account replacement air valves combines energy efficiency and healthy indoor air. There is no point in saving on heating costs if you are also creating indoor air problems that affect living comfort, health and the condition of the building.
Remember: Energy efficiency and ventilation go hand in hand. Don't ignore this, or what you initially thought was a savings could turn into a costly mistake.

How do replacement air valve work?
An air compensation frame valve is a simple but effective solution that uses natural gravity or mechanical exhaust ventilation to bring fresh outdoor air indoors in a controlled manner.
Three important operating principles:
Supply air direction: The valves direct cold air upwards, where it warms up before mixing with the room air.
Filtration: The best filters on the market, such as Filtrete, stop outdoor air pollution and pollen.
Automatic regulation: In some models, such as the Air-In Chameleon, the valves adapt to negative pressure and prevent backflow.
Most popular replacement air valve models
1. Pihla KLIK valve
Easy to use and stylish: Two versions – direct version for gravity ventilation and supply air version for mechanical exhaust.
Maintenance: The filter can be replaced without tools.
2. AA supply air window valve
Energy efficiency: Utilizes heat losses from windows to preheat the air.
Efficient filtration: The Filtrete filter stops small particles and pollen.
Retrofittable: Especially suitable for old windows.
3. Air-In Chameleon
Automatic adaptability: Adjusts itself to the negative pressure.
Check valve: Prevents air from flowing back.
Noise cancellation: Effectively eliminates outside noise.

Gravity ventilation: why is it still working?
Gravity ventilation utilizes natural pressure differences, such as indoor and outdoor temperature differences and wind conditions. Replacement air valves are critical in such a system, as they ensure that outdoor air flows in at the correct ratio to the air being removed.
Combination solutions
Gravity ventilation can be enhanced with modern technology, such as exhaust fans or solar-assisted chimneys, ensuring functionality even when natural conditions are insufficient.
Current requirements
Building codes require that air volumes, filtration and energy efficiency be met. Replacement air valves can be key to meeting these requirements when selected and installed correctly.
Installation and maintenance
The functionality of the replacement air valve depends on proper installation and regular maintenance.
Here is a quick guide:
Installation:
Measure and mark the location on the frame.
Drill the necessary holes and seal carefully.
Attach the valve and ensure the filter is installed correctly.
Maintenance:
Filter replacement twice a year.
Regular cleaning of the valve from dust and dirt.

Why choose IVAeris Oy?
In this industry, it's not enough for someone to do an "okay" job. You need the best possible team to do the job properly. IVAeris Oy is Espoo's leading ventilation expert company that doesn't just offer solutions - we solve your problems permanently.
Installation Services: Our professional team ensures you get the right solution the first time.
Consulting: Selecting the right valve models and optimizing the system to suit your needs.
Do you want to improve the indoor air quality in your home? Contact us today . IVAeris Oy is ready to do work that will last and improve the quality of your life.
WE KNOW, WE CARE & WE GET IT DONE
IVAeris Ltd.
010 206 3000