The final stage of the BUGDEATH project (James and Evans, 2005) was to further develop the surface heating and cooling apparatus so it would be suitable for commercial exploitation. The new apparatus can be accommodated on a bench top and produces faster more uniform heating and cooling cycles than that previously described. It can heat the surface of a food from 8 to 120 °C in 14 s, cool from 120 to 40 °C in 28 s and then to 8 °C in 5 min. There is an average control error of approximately ±1 °C and a temperature variation over the surface of the sample of only 1.2 °C. Wet heating, using steam at 100 °C, was achieved using a portable steam generator. The price of the parts which made up the apparatus were approximately €10 000 and it takes approximately two person-weeks to build. Keywords Food poisoning Surface decontamination Microbial models Heating and cooling equipment Surface temperature measurement 1 Introduction The design, construction and performance of the original apparatus developed as part of the BUGDEATH project ( James & Evans, 2005 ) to provide controlled heating and cooling cycles at the surface of food samples is described by Foster et al. (2005) . This paper describes improvements that were made, as a result of feedback from the project partners and knowledge gained in designing, building and using the original apparatus. The aim of the improvements was to create a piece of commercially viable equipment for exploitation after the end of the project. 2 Improved apparatus specification In consultation with the partners who were using the original apparatus a ‘wish list’ of improvements was produced for a ‘commercial’ system. From this wish list a final specification was produced. The final specification was that the: • Apparatus should cost less than €15 000 to build. • Apparatus should be small enough to be bench mounted. The steam generator and cooler would be separate units, but bench mountable. • Entire chamber should be capable of withstanding 200 °C for 3 min and 120 °C for 3 h. • Sample should be viewable through glass panels at any point in any process. • Software should control the surface temperature by a straight-line ramp as in the previous apparatus. • Controller should be a PC with a graphical user interface (GUI) to make it easy to use. • Apparatus should be capable of heating the surface of a sample from 0 to 120 °C in 20 s using dry air (fastest uncontrolled heating). • Un-pressurised apparatus should be able to heat the sample using saturated steam or superheated steam up to 120 °C. • Apparatus should be able to cool the surface of a sample from 120 to 40 °C in 15 s and then to 5 °C in 5 min. • Apparatus should control the surface temperature to an accuracy of ±0.5 °C and uniformity of ±1 °C. • Apparatus should operate from a 32 A single-phase electrical supply and only require compressed air for the cooling. • Process velocities over the sample should be less than 20 m s −1 to avoid the possibility of bacteria being blown off the surface. • Chamber did not need high efficiency particulate air (HEPA) filtration, however, exhaust nozzles should be provided to allow a filtration system to be easily attached. • Cooling should be possible immediately after a steam treatment. 3 Development of system It was evident from the previous apparatus that providing all the processes in one chamber made cooling more difficult. This was because the cooling nozzle was heated by, but could not be cooled during, the heating treatment. In the previous apparatus, the heating and cooling air and steam were delivered parallel (slightly above and from the side) to the rotating sample. However, despite sample rotation the whole of the surface was not uniformly heated. The heat transfer mathematical model developed in the project ( Kondjoyan et al., 2005 ) was used to aid in the design of the equipment and specify the heating and cooling treatments required. To improve the rate of cooling and uniformity of heating the new system was designed with four chambers (quadrants) and the heating or cooling medium introduced perpendicular to the surface of the sample. Air impingement techniques were used to enhance uniformity of surface temperature and produce faster heating rates ( Soto & Borquez, 2001 ). To minimise the effect of the environment on the process jet due to entrainment, two design rules were followed. (1) The diameter of the process nozzle was at least as large as the diameter of the sample and (2) the nozzle was a distance of less than 5 nozzle diameters away from the surface of the sample. A distance of five nozzle diameters from the nozzle has been shown to be where the potential core of the jet ends ( Rajaratnam, 1976 ). The potential core is the central region of the jet that is unaffected by the entrainment and so not subject to a temperature change. Allowing the treatment nozzle to be placed directly above the sample surface meant that the IR thermometer could not also be placed directly above the surface, as in the previous apparatus ( Fig. 1 ). The measurement of surface temperature is explained in more detail in Section 4.5 . The diameter of the sample was now critical to the design of the apparatus. A smaller sample diameter would reduce the size of many key elements, including the nozzle diameter. It would also reduce the airflow rate, for a given velocity, and therefore the power of the heater required to provide the same temperature in the hot air stream. A borosilicate glass Petri dish (237553903, Schott AG, Mainz, Germany) with an external diameter and height of 40 and 12 mm, respectively, was chosen. This was the smallest standard size available, which provided a large enough surface to inoculate with bacteria. In the new system the treatments were carried out in...

To reduce energy consumption and greenhouse gas emissions, the adoption of efficient refrigeration and cooking equipment and other innovative technologies need to be considered in the food service sector. In quick-service restaurants (QSRs), there is a strong interaction between the structure, internal machinery, and heating, ventilation, and air conditioning (HVAC) system. The impact of these interactions in a UK-based QSR was modelled using EnergyPlus™ 2022 v22.2.0. The modelling examined the effects of applying carbon reduction technologies, predicted climate change impacts, and electrical grid carbon intensity (EGCI) from 2022 to 2050. The findings revealed that among the individual technologies applied, an enhanced efficiency of 20% in refrigeration and kitchen equipment gave the most favourable outcome, contributing to a 15.7% reduction in carbon emissions. The results also showed that climate change impacts on the energy consumption of the QSR were minimal. Additionally, combining technologies could achieve savings of 35.9% in carbon emissions, while predicted changes in the EGCI could potentially yield a 98% reduction in carbon emissions between 2022 and 2050. The findings highlight the significance of the early adoption of carbon reduction technologies to minimise cumulative emissions. These insights offer a foundation for developing more effective carbon reduction strategies in the food service sector.