Food-service facilities have high energy intensities compared to other commercial buildings due to their energy use for cooking and refrigeration. Assessing the energy performance of such facilities has two main purposes. The first one is to evaluate how efficient food-service facilities are and to compare the results with other similar facilities.
The second objective is to get a deeper analysis of the energy uses, what enables an easier identification of the processes whose energy efficiency can be improved. This thesis gives, in a first part, a general methodology of how such an energy performance assessment could be carried out. In a second part, a Swedish restaurant – Långbro Värdshus – is taken as a case study.
This case study consists in an analysis of the cooking appliances’ energy use and an energy performance assessment of the whole facility. A first result of this thesis is the importance of the definition of the system before to start the assessment. Lack of information about the considered processes or how energy use is estimated makes comparison and benchmarking difficult and potentially irrelevant.
A second important aspect that stands out of the study when dealing with energy efficiency is the choice of a meaningful indicator. In the case of food-service facilities the amount of energy used per meal (typically expressed in kWh/meal) seems to be the most appropriate one.
As regards the energy efficiency of Långbro Värdshus, it has been estimated at 5.9 kWh/meal when considering the total energy use of the facility and at 4.1 kWh/meal without HVAC systems’ energy use. Concerning the cooking appliances, the monitored data of their electricity consumption have been analysed to identify the influence of the heating technology and behaviours on the energy use.
It resulted, for example, that replacing two hot plate range tops by a solid top and an induction range top enabled 38 % energy savings. Moreover, training the personnel reduced by 7 % the total energy use of the monitored cooking appliances.
Source: KTH
Author: Paillat, Etienne
>> Heat Energy and Thermodynamics based Projects for Mechanical Students