Hotel Case Study

The century-old Hotel Mediodía is located in Madrid’s cultural center. Faced with rising energy costs and municipal bylaws for conversion to renewable systems, it needed to embrace new technologies without damaging its antique aesthetic.

The hotel has 173 rooms, with almost 100% occupancy year-round. It has a restaurant and bar, a laundry area, as well as central air conditioning. The building heated 10,200 liters of potable water per day, which equated to a monthly demand of 696,827MJ.

A renewable energy plant was designed to meet the building’s thermal needs. This comprised of a closed-loop solar-thermal field featuring 50 flat plate collectors with a net aperture of 127 m². These were connected to feed 2 storage tanks with a total volume of 10,000 liters. The working fluid is an aqueous solution of 30% glycol. This helps to avoid the risk of frost damaging the system.

The solar fraction is about 50%, which translates to a monthly energy saving of approximately half the original bill.