Drain back solar solutions for DHW production in hotel installations

Solar powered systems save energy, reduce the CO2 emissions of the building and lead to an economic saving that facilitates their amortisation, especially in hotel installations characterised by high and more or less constant levels of DHW consumption all year round. However to achieve this, these systems have to be well-designed, simple structures using reliable and efficient technologies and equipment that minimise necessary maintenance actions.

For example, for a 4-star hotel with an occupancy of around 100 people a day, a solar installation could be designed to cover 60% of the needs arising from DHW demand by installing a solar powered system with a working surface area of about 60 m2 and 4,000 litres of accumulation. The energy obtained through this clean and renewable system would represent a saving in fuel that, in the case of natural gas, would amount to almost 2,700 € per year and would avoid the emission of 17,254 kg of CO2 per year into the atmosphere. To achieve these savings values, the equipment and the type of system to be implemented have to be very carefully selected to protect the solar installation from its main risks: over-heating and freezing.

ACV has over 15 years experience in the manufacture of solar powered systems and is leader in the design, development and commercialisation of Drain Back technologies for tertiary-type installations. ACV’s Drain Back system empties heat-bearing fluid from the collector tank in the event there is a risk of over-heating or freezing, stopping the pump. Using gravity, the fluid is emptied into the drainage tank and air rises through the collector field. The unit is automatically refilled when the situation returns to normal (activating the pump, letting air fill the drainage tank so that the liquid goes back into the solar collectors). Read more…

Gaspar Martín
ACV, Technical Director

Article published in: FuturENERGY June 2015