This report will show the energy usage of Hotel Princess in Sandviken, Sweden. When the hotel changed owner an examination of the hotels heating, ventilation and sanitary systems were done. The report showed flaws in the ventilation system, and is why the new owner wanted a closer look at the energy use of the hotel.

The original building was built in the 1930s and two major extensions have been built, one in the 1950s and the most recent in the 1980s. An assumption made is that the building parts were built to the restrictions during the time. Activities on the hotel include sleep over, conference, night club, massage and swimming in the hotels pool section. District heating is the primary source of heat and is produced at the CHP-plant in Sandviken.

When investigating the energy use of a building, an energy balance is constructed.  In an energy balance the energy added is equal to the total energy losses. The added energy consists of bought energy (district heat) and “free” energy (heat from humans, electric apparatus, solar energy and lights). The losses include unwanted ventilation, transmission, ventilation, and tap water losses. Calculations have been done with help of collected statistics, measurements and conversations with the hotel staff.

The result shows that the total energy use is more than 1 400 MWh every year.  About half of the energy losses come from transmission through the building construction. Almost one fourth of the energy losses come from the ventilation system, just above 10 % from tap water and about 13 % from unwanted ventilation. To heat the building and hot water, about 4/5 district heat and 1/5 “free” energy is used.

Investigating the ventilation system revealed problems, the largest being that several ventilation units were out of function and some showed large differences between supply and exhaust air. Installing a ventilation system with variable air volume (VAV) could lower the energy demand to heat ventilation air by roughly 73 %, equal to about 140 000 kr every year. A new ventilation system is a large investment, however, and it is not likely be a profitable investment within a 15-year period.

Further work could be:

• Investigate the ventilation units that are out of function, especially the pool ventilation unit.
• If necessary, check what the price of a new ventilation system would be.
• Update the drawings of the current ventilation system, if it is going to be used in the future.