Today, buildings still account for almost half of the global energy consumption and carbon emission. This highlights the necessity to increase energy efficiency requirements worldwide in a common effort to reduce the construction sector's impacts on the environment. The current energy policies are driving toward a design that relies on airtight and highly insulated envelopes. As a consequence, energy efficient houses are found to have insufficient indoor air change rates, impacting on the indoor air quality and resulting in higher latent loads.

This paper aims to review the state of the art technologies for the energy efficiency within the hospitals sector. Hospitals are liable for an unstable amount of energy demand and joint emissions, because of their 24/7 nature of operation and hence resulting larger energy consumption than a typical commercial building. Additionally, they need high quality and warranted supplies of electricity. Due to increased energy demand and therefore the depletion of existing fossil fuel based sources, it is required to use the energy more efficient.

Naturally ventilated buildings have been worldwide increasingly welcomed, given the current global awareness toward environmental sustainability, indoor health-quality and renewable energy. As Natural Ventilation (NV) performance relies on building design and interaction with the local environment, its potential benefits are not always easy to take advantage of, and thus sets up a vital field of study. This paper provides an overview of investigations on the subject by collecting researches focused on thermal comfort, energy efficiency and indoor air quality.