The ventilation required in order to maintain acceptable indoor hygiene standards results in a significant consumption of energy. Currently the Spanish regulations on indoor air quality (IAQ) require minimum rates for delivery-to and extraction-from the habitable rooms of residential buildings. These rates are not adjustable, so ventilation systems based on variable ventilation rates, are not normally deemed acceptable unless a comprehensive statement of compliance is provided, justifying the proposed ventilation solution. However the use of variable ventilation systems is desirable, as it would almost certainly produce a reduction of the overall ventilation rate and, consequently, a reduction in the heating and cooling energy demand while maintaining a good level of air quality.
This paper presents part of the ongoing research towards the modification of the Spanish regulations in order to adapt required ventilation rates to real needs. This would mean allowing reduction in ventilation rates and energy demand but without any impact on indoor air quality.
The objective behind this research is to propose to the Spanish Government the substitution of the current required constant ventilation rates by maximum values of CO2 concentration as an indicator of air quality. By establishing maximum values, the implementation of ventilation systems based on variable ventilation rates will be enabled because the justification will be more easily provided.