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Above-limit values must be reduced immediately by ventilating and leaving the area at once. A
malfunctioning heat source that exhibits imperfect combustion must be repaired immediately. Typical
household levels should be in the range of 0–9 ppm. Higher values indicate an active source of CO at home.
Carbon dioxide concentration CO2
– Most carbon dioxide in occupied rooms is generated by the
breathing of people inside the room. The concentration increases with the number of people in the room
and the length of time the room remains unventilated. Increased CO2 concentration can cause fatigue,
tiredness and poor concentration.
Excessive levels can be reduced by ventilating the space. Drops in the value on the indicator should
be apparent within minutes. Atmospheric values range between 300–450 ppm. 650–800 ppm is considered
a poorly ventilated space. The maximum acceptable level for long-term residence is typically 1000 ppm.
Higher levels lead to fatigue, headaches and other health problems.
The appropriate alert limit should be set between 1000–1500 ppm.
Relative concentration of volatile organic compounds (VOC)
– This is the sum of various organic
compounds that can be present in the home and can cause respiratory irritation, respiratory problems or
allergies and can affect a person's immunity. Such substances include ethanol, components of cigarette
smoke, perfume droplets, household cleaners, fumes from binders (glues) in furniture, paint, kitchen fumes
from frying, burning wax candles and other sources.
The exact measurement of VOCs is very complex because it depends on many factors, in particular
the presence of specific substances in the air. Therefore, the product applies the principle of relative
indication, which is relative to the clean outdoor environment, indicated by percent. Values approaching
100 % indicate extremely polluted air. The normal value of this indicator in a household should be in the
range of 10–50 %.