We breathe 12,000 litres of air with the 26,000 breaths we take every day & because we spend 90% of our time indoors, indoor air quality is crucial for our health.

Contrary to what many people think, the inside air quality is on average +10 times worse than the air quality outside of our home. The first reason why this is possible because we pollute our homes ourselves by cooking, showering, heating, cleaning, sweating and EVEN breathing!

The second reason is because the outdoor pollution cumulate in our home due the low air change. Outside, we have the wind and time to time it cleans our polluted air, but this is not happening in our homes there the pollution always increase without ventilation.

Our sensors

If we ask someone about the temperature inside home, the answer is correct within a few Celsius and we know if we have cold so we can change the temperature with the thermostat. Sadly we have no sensor in our body to detect pollution. We can`t detect the CO2 level, the humidity level or the VOC level. This is the reason why it is important to understand what is polluting our homes what can we do against and how can we choose a good ventilation system.


Continuous high humidity leads to odours, condensation and mould and increases the number of bed mites. Bed mites eats our skin cells, they live in mattresses, beddings, textiles, towels, upholstered furniture carpers.

Did you know dust is mainly skin cells? What we call dust allergy is not an allergy for our skin cells, dust allergy is the allergy for bed mites and their “waste” and enzymes they produce.

Bed mites enjoy high humidity. They can eat with their mouth but they cant drink with it. They only absorb water from humidity through their skin. So they do not survive in low humidity conditions (under 50%) and their numbers decreases when the humidity is normal but even a short humid period can give them the chance to live. Read more here.

Bacteria, fungi's also loves high humidity and they grow exponentially when the humidity is high. and this 2 leads to asthma and allergies.

So, with other words, low humidity level means, fewer bed mites, less fungi and better indoor air quality. Better IAQ, reduce or stop the symptoms of allergy and asthma. Normal humidity levels also mean no mould & no condensation in our homes.


Almost every building material release VOCs (volatile organic compounds) for a very long time (+20 years). Furniture, wall coverings, flooring, plastics release VOC. Formaldehyde, one of the most common VOCs, it`s a colourless gas with an acrid (sharp and bitter) smell. It is common in many building materials such as plywood, particleboard and plastic, glues.  Formaldehyde can also be found in some drapes and fabrics and certain types of foam insulation. VOCs include a variety of chemicals that can cause eye, nose and throat irritation, shortness of breath, headaches, fatigue, nausea, dizziness and skin problems.

Higher concentrations or long term exposure may irritate the lungs, as well as damage to the liver, kidney, or central nervous system. Some VOCs are suspected of causing cancer and some have been shown to cause cancer in humans. The health effects caused by VOCs depend on the concentration and length of exposure to the chemicals.


We all know the deadly consequences of CO (carbon monoxide) but do we know the effect of CO2 of our body?

Co2 is not deadly, except if you breathe co2 in high concentration and this is, of course,  hardly possible at home. Our body constantly burning from the moment we born to the last breath we take.

We Breath oxygen, “burn it” and breath out CO2. So it`s natural. But when we are in a small space like our bedroom the Co2 level can reach a high concentration, above 1200ppm. So the “our fire” doesn’t burn anymore in the same efficient way. Sounds strange? Yes, but true.

Our brain, organs & our body will not work efficiently if the Co2 levels are high.  Research shows people that sleep & live in a good oxygen level environment are fitter & more energetic. On the other hand,  people with poorly ventilated areas, offices, homes are more likely tired, having more headaches and similar symptoms.


Is it a new thing in our life?

No. But in the last decades, our buildings become tighter and tighter and the air changes reduced or stopped.

In our grandparent’s time the houses were leaky, but with our modern building technologies, we reduced the natural ventilation in our homes.

Starting from the 80`s we improved a lot in our buildings, better insulation, less heat loss, but a few years later we saw an exponential increase in allergy & asthma-related problems.


Because we forgot what the previous generations knew, that we still need to ventilate our homes.

In a modern home, opening a window will not work because the house is so tight there is no flush, it`s not effective and it costs money. We will end up with huge heat loss and very little air changes. During the night, we won't start opening our windows or switch on our bathroom fans if the IAQ deteriorate.

Is it a problem? Why we build airtight buildings?

The key here is control. We want to reduce the heat loss and uncontrolled ventilation.  We want good indoor air quality. If your home is leaky, on a windy day you have over “ventilation”, maybe not in the right area, if there is no wind you have no “ventilation”. So a leaky building has a high heat-loss and over or under ventilation.

In a modern building, we can minimalise the heat-loss and with intelligent ventilation, we can provide excellent indoor air quality with minimal heat-loss caused by the ventilation system. 

This is the reason why in our modern airtight homes we need modern mechanical ventilation.

Modern ventilation

Even better if our ventilation system knows the indoor air quality and can adjust the ventilation rates according to the pollution. Why you want to ventilate all day the same way if you have different pollutions every time. 

i-ventilation is committed to promoting intelligent, modern ventilation systems for your home

We truly believe we have systems that make life healthier while still reducing energy use.

Most of the pollutants we can`t even detect by ourselves.  It is the XXI century we have AI, sensors, apps intelligent solutions 

Demand Controlled MVHR units [best 3 i-MVHR units]

Demand controlled Heat recovery units with Humidity, CO2 and VOC sensor and Passive house certificate: