With climate change a reality, we are witnessing severe weather changes all over the world. Previous studies have shown that the hot places are becoming hotter. It is predicted that by 2050 most of the world population will live in the tropics with higher temperatures. This means higher energy costs due to increased use of air conditioning.
New research from Singapore indicates that by slightly raising indoor temperature in office buildings and using smart fans will save significantly on energy costs and also maintain employee comfort. This research was conducted by a consortium of engineering specialists from US and Asia.
=Q=
In the United States, approximately 75 per cent of the electricity goes towards providing air conditioning in buildings. 40 per cent of the total energy utilized accounts for air conditioning and relative greenhouse gas emissions in the US and worldwide.
This research was conducted in the tropical city-state of Singapore where 50 per cent of electricity is consumed by residential and commercial buildings, mostly to run air conditioners for occupant comfort and to dehumidify air conditioned spaces.
The temperatures are typically set at 23°C for office buildings in Singapore and the yearly average outdoor temperature during the day is 29°C.
The objective of the research was to show that it was possible to provide same or more comfort with the use of less energy by turning up the thermostat.
The study was conducted in five separate experiments in the summer of 2014. 56 participants who were dressed in typical Singaporean attire of long pants, short-sleeved shirt, socks and closed-toe business shoes, gathered in a room at Nanyang Technological University featuring an open-office layout with no cubicles.
During the 90 minute tests, participants were asked how they felt to understand their comfort level based on temperatures that were adjusted to 23°C, 26°C and 29°C. Relative humidity was maintained at 60 per cent, which is typical indoor level for Singapore. For two tests at 26°C and 29°C, participants could control air movement with personal electric fans if they so desired.
The electric fans were energy efficient desk fans that ran on direct-current (DC) motors between 3 and 17 watts, rather than alternative-current (AC) motors that utilized 100 watts.
Researchers found that thermal comfort, perceived air quality, and sick building syndrome symptoms are equal or better at 26°C and 29°C than at the common set point of 23°C, if a personally controlled fan is used.
The best cognitive performance determined by task speed was at 26°C. At 29°C the use of an electric fan partially reduced the negative effect of increased temperature. Set at the typical set point of 23°C yielded the lowest cognitive performance.
The researchers concluded that setting the temperature between 26°C and 29°C in air-conditioned buildings in tropical regions and providing occupants with personally controlled fans is a viable option for providing thermal comfort while being cost-effective, sustainable and energy efficient.
If this option is applied to buildings in Singapore, researchers claim a 35 per cent saving in energy for air conditioning.
With the use of air conditioning is already exploding in most tropical countries, this research becomes significant with forecasts of hotter temperatures in the future along with the growth of densely populated areas and a wealthier planet.
The researchers of this study have already started working on smart fans that can adapt to environmental changes and provide much needed comfort at the same time.
It seems that adjusting your air-conditioners thermostat and investing in an energy efficient fan might be the answer to saving on energy costs.
