Energy Efficiency in the Brazilian Built Environment - Retrofitting strategies for a hotel in Goiânia

The building chosen as a case study is a hotel placed downtown Goiânia. It is classified as business economic since its high guests’ turnover, medium tariffs and central localization, close to the municipal convention center, so its main public is composed by conferences’ participants, lecturers and groups. With 16 floors and 196 rooms, 182 regular rooms for two people and 14 rooms senior, of higher standard.

Ground floor is composed by reception, reunion rooms, restaurant, bar, administration and general kitchen. In the last floor, instead, there is a terrace with spa, sauna and fitness center; furthermore 14 other floors are composed by 14 rooms each other (from which 13 are regular and 1 senior). All these 16 floors are air-conditioned with individual equipments, known as ”window conditioners” with simple personal control of temperature: each room has its own air conditioner and other individual devices are spread out other common spaces on first and last floors. Therefore underground floors are available for garages, with no spaces of regular occupation.

Building’s main wide façades are beige and narrow laterals are brown with white details. Horizontal surfaces are flat roofs, essentially cast concrete slabs with cement grout covering. Windows are about 14% of façades’ total area and are composed by simple aluminum frames and simple glasses with no film application. Most windows’ openings are vertical, with ventilation flaps.

Building have four lifts, being three for guests and one for services, and there are two staircases for security reasons. Several technical shafts are positioning between bathrooms, for hydraulic installations, and some other of several dimensions are distributed on building for electric, logistic and fire insurance installations, as well as pipes for mechanic ventilation and air exhausts.
The last floor, called terrace, occupies just a part of tower’s horizontal projection on its center portion, and the uncovered external horizontal area in the same level is surrounded by walls, part of façades’ conception. Assuming that underground floors are not considered within building’s area for energetic estimations, since it is a space of irregular occupancy, no air conditioning, no appliances and a artificial illumination system activated by presence sensors building, hotel’s gross area is around 8041m2 as above mentioned. This is the area to be used on building’s index of performance calculation.

Relevant documents regarding building’s project, used technologies and current energy consumption in the hotel have been provided by its administration. Concerning electrical energy bills, as presented above, data regarding only seven of the twelve months in 2010 was provided. Nevertheless the annual energy consumption in the whole year is also reported on documentation and is about 536 MWh. Energy consumed within the building is predominantly electrical, and natural gas is used only on central kitchen ovens.