Energy-efficient houses

A low-energy house consumes less energy than a regular house, passive houses consume the absolute minimum, and so-called zero-energy buildings theoretically should not need any energy at all.

These houses utilize passive energy sources, such as light bulbs, computers, televisions, and human heat. For example, one adult “heats” the interior with an output of about 200 watts, and when there are four people in a household, or even better in a school where there are twenty children in one classroom, it becomes noticeable.

Furthermore, in heat exchangers with heat recovery, heat from the exhaled (contaminated) air is transferred to the fresh cold air. So, at 20 °C inside and 0 °C outside, fresh air can be heated up to 17 – 18 °C. For heating, because in frosty weather you still need to heat a bit, you will spend instead of forty thousand perhaps only five thousand crowns annually.

You can find the range of CO₂ sensors here

Passive houses are not yet that widespread with us, their construction accounts for only a few percent. In contrast, in Germany or Austria, they are significantly further along, where about ten percent of such houses are already being built.

The alpha and omega is measurement. This is where air quality sensors come into play. Sensors allow for easy and inexpensive continuous measurement of indoor air quality, for example, by monitoring the concentration of CO₂ in the air, and based on the obtained values, controlling ventilation systems to ensure good air quality while minimizing energy consumption. Such systems are particularly useful for spaces with a variable number of people. The ventilation performance is then continuously adjusted depending on the number of people present in the ventilated space. A high concentration of carbon dioxide induces stale air, which then causes fatigue, drowsiness, reduces concentration, etc. Consequently, productivity in such a space dramatically decreases.