Popular varieties of ventilation systems with heat recovery are those which have been widely adopted due to their effectiveness and cost efficiency. These systems primarily achieve savings in energy, cost, and performance while maintaining an optimal balance between these factors. They may have features such as simple installation, low maintenance, and dependable operation. Popular ventilation systems with heat recovery can be used in residential, commercial, and industrial buildings. Their key selling point is that they save substantial energy while maintaining indoor air quality and comfort.