Influence of the Improvement in Thermal Expectation Levels with Adaptive Setpoint Temperatures on Energy Consumption

Abstract

A sustainable use of active heating, ventilation, and air conditioning (HVAC) systems is crucial for minimum energy consumption. Currently, research studies are increasingly applying adaptive setpoint temperatures, thus reducing considerably the energy consumption without influencing comfort levels excessively. Most of them, however, are focused on the limit values of adaptive comfort standards without considering the tolerance in users’ adaptation capacity. This research study analyzed various tolerance ranges in the recent adaptive thermal comfort model from EN 16798-1:2019 used in setpoint temperatures. The study focused on the south of Europe, considering 47 cities in Spain, 18 cities in Portugal, 13 cities in Greece, and 20 cities in Italy. In addition, such cities were analyzed in three climate scenarios: present time, 2050, and 2100. The results showed that values prefixed by EN 16798-1:2019 for new buildings (tolerance of 0.00 °C) produced significant savings with respect to the static model and that each progressive improvement in users’ thermal expectations in 0.25 °C increased the energy consumption between 6.57 and 9.31% in all scenarios analyzed. Even applying a thermal tolerance of 1.50 °C, energy savings are currently produced with respect to the static model. This tendency increases in future scenarios until a thermal tolerance of 1.75 °C. The results of this paper provide greater knowledge about the possible energy increase that the improvement in users’ expectations would produce.

Experimental Comparison of Heating Emitters in Mediterranean Climate

“…By means of simulations for typical USA single-family homes, Moon and Han [34] found a linear increase of 5.4%/ • C for heating consumption in a cold climate passing from 15.6 to 26.7 • C. According to Ghahramani et al [35], the potential savings from selecting daily optimal set-points in the range of 22.5 ± 3 • C for small, medium, and large office buildings would lead to 10.09-37.03%, 11.43-21.01%, and 6.78-11.34% savings, respectively, depending on the climate. Bienvenido-Huertas et al [36] demonstrated that the set-point values prefixed by EN 16798-1:2019 for new buildings can bring significant savings with respect to the static model.…”

Geothermal energy concept applied to All-Air HVAC system

“…Residential HVAC systems are estimated to account for 40% to 60% of household energy consumption in residential buildings. Given their influence on the environment in the residential sector, this emphasizes the necessity of energyefficient HVAC solutions [14][15][16]. The energy footprint of residential HVAC systems varies according to building size, user habits, insulation quality, climate, and system efficiency [17][18].…”

Nudging and usage of thermal comfort-related systems

“…Papadopoulos et al (2019) make the case for re-thinking HVAC temperature setpoints in buildings by applying a multi-objective optimization framework, resulting in a 60% reduction in HVAC-related loads in moderate-climate regions without adversely affecting thermal comfort levels. Numerous papers (Bienvenido-Huertas et al, 2020;Ghahramani et al, 2016;Guillén-Lambea et al, 2017;Aghniaey and Lawrence, 2018) also make clear the potential for application of adaptive principles to allow variation in HVAC set-points for saving energy.…”