Towards zero energy hospital buildings – energy saving opportunities in steam and humidification installations

Abstract

The healthcare sector is highly energy intensive with circa 6% of the total global energy consumption. For this reason, hospitals strive to reduce their energy usage, especially of the most energy intensive systems like steam and humidification installations. Centralized steam plants are widely used by hospital complexes since many hospital functions rely on steam to properly fulfil its purpose (e.g. air humidification, sterilization, space and water heating, kitchen boilers). Central steam plants are not the most energy-efficient method to supply the consumers’ demand due to the high energy and fossil fuel consumption for steam production and the consequent losses inherent to the extensive distribution installations. In general steam losses in steam system can represent over 30%. Total CO2 emissions for steam production can be over 20% of which humidification can represent over 50%. Therefore reducing the steam demand for humidification and implementing decentralized systems is of great importance for Hospital Buildings to fulfil for new buildings the nZEB requirements. In this paper the results of a literature study are presented and a method based on the so-called 5-step method [1] and the Kesselring method is used to select different systems based on their performances on different aspects. Solutions are presented that can save more than 50% of energy use and CO2 emissions used for the steam production.