Fictitious cooling/heating: from free-floating thermal discomfort to energy needs, different approaches toward labelling free-running buildings

Free-running (FR) buildings and technologies, e.g. ventilative cooling, are generally not considered and valorised in energy labelling schemes. The paper analyses three approaches to transfer discomfort conditions into comparable fictitious energy needs in order to evaluate FR building performances. The first approach adds a virtual mechanical system to the FR building; the second approach includes in the previous the effect of controlled free-running potentialities, e.g. ventilative cooling in summer, while in the third one, fictitious energy needs are calculated by coupling a double simulation flow, i.e. FR vs mechanical-treated building, assuming energy needs from the latter when the first is exceeding assumed discomfort thresholds. The paper underlines a very high correlation between energy needs and parallel FR indoor temperatures. Initial results show how the first approach loses the FR potential, while the second and the third can valorise FR technologies. The choice of different discomfort thresholds can be used to orient the impact of FR technologies from very to slightly positive.