**5. Conclusion**

130 Energy Efficiency – The Innovative Ways for Smart Energy, the Future Towards Modern Utilities

**Figure 13.** a. Case 2: Monthly electric consumption, b. Case 2: Monthly gas consumption

**Figure 14.** a. Case 3: Monthly electric consumption, b. Case 3: Monthly gas consumption

In the absence of air conditioning system, the predicted indoor temperature evolution throughout the year suggests that there is significant potential for intervention to improve the performance of the activities in ITV workshops.

For what respects to the more efficient system to air conditioning a wide open workshop, the analysis of the energy consumption during a year simulation allows to conclude that high efficient system like the proposed, composed by a solar heating installation with a condensing gas boiler auxiliary power option, air curtains for environmental thermal control and displacement ventilation supplied by a dedicated outdoor air handling unit with evaporative indirect cooling, reduces electric consumption to 37% and gas consumption to 35%, compared to a conventional HVAC system.

From the point of view of its efficiency, it is highlighted the importance of the general conception of the system, instead of placing design efforts in improving the performance of its components.

The comparison between systems should be done in terms of primary energy and carbon emissions, rather than based on economic criteria. European legislation states that a system of energy performance certification is a mandatory requirement for rented, sold or constructed buildings. In response to this, Spain's recent building regulations have established the process of certification of new buildings. A series of tools are provided to calculate whether the new buildings are highly efficient (class A) or least energetically efficient (class G). The official program used for this process of certification is called CALENER and provides an average carbon value of the overall building energy performance, and classifies it by means of a comparison of the performance of the building systems and construction materials with their corresponding reference values.
