To breathe better and keep our rooms healthy, just keep the temperature at 19-20 ° C (66-68 °F), open the windows and use devices for air purification

It is better to know that…

All the harmful substances and pollutants that we can find inside our homes, including those mentioned in the previous article as possible carcinogens, are commonly called “Volatile Organic Compounds” (VOC)

As we saw last week, these substances are often invisible and odourless, representing uncomfortable living situations for us.

What has not yet been said is that these compounds are highly sensitive to the heat inside homes, in fact the vapour pressure of the VOCs is exponentially proportional to the ambient temperature.

Let’s imagine, for example, putting a pot of water to heat on our stoves: as the temperature increases, the water in the container evaporates faster and faster and then spreads throughout the kitchen. Vapour pressure is the force with which water molecules tend to exit their liquid state and turn into vapour.

We can say that VOCs behave like water: as the temperature increases, their evaporation increases, and therefore their vapour pressure.


By raising “our thermostat” even by a few degrees, we significantly increase the probability of breathing in the house significant quantities of polluting molecules, which inevitably affect the healthiness of confined environments in a negative way.

Fortunately, every cloud has a silver lining, in fact we can turn this precious knowledge we have just acquired to our advantage: we keep the home temperature at 19-20 ° C (66-68 °F), without therefore bringing it to too high values, and we will certainly breathe better by decreasing many symptoms related to climatic discomfort such as headache, fatigue and irritability.

It is clear that for our psychophysical well-being we should ultimately worry about dressing more heavily even when we are indoor.

This virtuous attitude will also mean significant savings in utility bills.

The other thing we can definitely do to improve indoor air quality is to open the windows in order to facilitate aeration.

The advice of this good habit derives from the knowledge, already emerged during our discussion on indoor pollution, that inside the house we have a polluting concentration up to 5 times higher than the outside.

We often air our rooms, even in winter for a few minutes; maybe we can help ourselves by inserting a simple hygrometer inside the house that indicates the level of internal humidity reached (perhaps after cooking, taking a shower or hanging clothes in the laundry). When the hygrometer marks 65% relative humidity, it is time to open the windows.

Useful tools

Similarly, you can buy a CO2 meter (carbon dioxide) for a few euros that helps you know when to open/close your windows: when the appliance marks 1,100 ppm (parts per million) it means that the room begins to be too saturated by the carbon dioxide generated by the occupants or by the combustion or cooking processes carried out in it. When it is not possible to air the rooms, it is appropriate to use air purification and purifying devices.

These and other tips to keep our environments healthy will be addressed over the weeks with the continuation of the knowledge base on pollutants.

Architect Leopoldo Busa,
Expert in indoor air quality