Abstract
Thermal comfort has direction implications for energy efficiency and sustainable development. From a global perspective, about 40% of total primary energy is used in buildings, contributing to more than 30% of CO2 emissions [1]. The fact that the common practices of clothing choices have impact on energy efficiency is ignored [2-3]. This paper analyzed and proposed clothing insulation required for energy efficiency (IREQee) in order to increase indoor temperature interval and energy efficiency.
In many heated/air-conditioned indoor environments, it is not unusual that occupants wear T-shirts/suits. The basic clothing insulation of these clothing ensembles is estimated to be about 0.5/1.0 clo [4]. The benefit of adding/reducing clothing insulation in heated/cooled environments, e.g. change clothing between 1.2 and 0.4 clo, is that the temperature of the whole room or building can be changed by 5.1 °C (between 20.4 and 25.5 °C) while still maintaining thermal comfort (Fig. 1) calculated according to international standard [5] and related web based tool [6], given that other parameters are the same (metabolic rate M=70 W/m2, relative humidity=50%, mean radiant temperature=air temperature, mechanic work=0, relative air velocity (m/s)=0.0052*(M-58)). As a result, the energy for heating/cooling the indoor environment is saved. The saved energy is about 10% for each degree Celsius decrease or increase in heated or air-conditioned indoor air temperature [7]. Hence, informed occupant’s clothing behavior change based on IREQee can extend the interval of comfort temperature, e.g. from 18.6 to 26.1 °C (rather than a fixed set point at 22 or 23 °C) for office work in heated and air-conditioned environments. The analysis indicates that the proposed IREQee in relation to physical work intensity can function as a low cost measure to maintain thermal comfort, save energy, and enhance sustainable development.
Figure 1. Required clothing insulation for energy efficiency (IREQee) and comfortable temperature in heated or air-conditioned indoor environments in relation to physical work intensity (metabolic rate: M=70 and 100 W/m2 corresponding to office work and low physical intensity work).
In many heated/air-conditioned indoor environments, it is not unusual that occupants wear T-shirts/suits. The basic clothing insulation of these clothing ensembles is estimated to be about 0.5/1.0 clo [4]. The benefit of adding/reducing clothing insulation in heated/cooled environments, e.g. change clothing between 1.2 and 0.4 clo, is that the temperature of the whole room or building can be changed by 5.1 °C (between 20.4 and 25.5 °C) while still maintaining thermal comfort (Fig. 1) calculated according to international standard [5] and related web based tool [6], given that other parameters are the same (metabolic rate M=70 W/m2, relative humidity=50%, mean radiant temperature=air temperature, mechanic work=0, relative air velocity (m/s)=0.0052*(M-58)). As a result, the energy for heating/cooling the indoor environment is saved. The saved energy is about 10% for each degree Celsius decrease or increase in heated or air-conditioned indoor air temperature [7]. Hence, informed occupant’s clothing behavior change based on IREQee can extend the interval of comfort temperature, e.g. from 18.6 to 26.1 °C (rather than a fixed set point at 22 or 23 °C) for office work in heated and air-conditioned environments. The analysis indicates that the proposed IREQee in relation to physical work intensity can function as a low cost measure to maintain thermal comfort, save energy, and enhance sustainable development.
Figure 1. Required clothing insulation for energy efficiency (IREQee) and comfortable temperature in heated or air-conditioned indoor environments in relation to physical work intensity (metabolic rate: M=70 and 100 W/m2 corresponding to office work and low physical intensity work).
| Original language | English |
|---|---|
| Title of host publication | Proceedings of the 11th International Meeting on Thermal Manikin and Modeling(11i3m) |
| Editors | Faming Wang, Ming Fu |
| Place of Publication | China |
| Pages | 28-29 |
| Number of pages | 2 |
| Publication status | Published - 2016 Oct 12 |
Subject classification (UKÄ)
- Textile, Rubber and Polymeric Materials
Free keywords
- thermal comfort
- energy efficiency
- clothing insulation
- IREQ
