Improving the energy efficiency of buildings could have benefits for the health and comfort of the occupants, as well as saving on energy costs, according to research from Lawrence Berkeley National Laboratory.
Researchers Mark Mendell and Anna Mirer collected data from 95 air-conditioned building across the US on various environmental factors such as temperature and humidity throughout one week in either summer or winter. They compared the data with the recommended ‘comfort’ ranges set by ASHRAE (the Association of Heating, Refrigerating and Air-Conditioning Engineers).
What they found was surprising. On average, building temperatures in summer are kept below the recommended comfort range and were actually cooler in summer – by almost 1°F (0.5°C) – than in winter.
Not only does this mean that more than half of the buildings surveyed are being overcooled in summer, wasting energy – it is also not good for the occupants.
The researchers asked building occupants to complete surveys about any ‘building-related symptoms’ such as headaches, fatigue and difficulty concentrating, as well as symptoms related to the upper and lower respiratory tract, eyes and skin.
In buildings kept below 73.4°F (23°C), the researchers found a 50% increase in the number of respondents reporting building-related symptoms such as headaches, fatigue and difficulty concentrating.
While winter building temperatures do fall within recommended ranges, when the average indoor temperature is above 73.4°F (23°C), there is a significant increase in the number of occupants reporting nose, eye and skin symptoms and headaches.
“As we look for ways to save energy, these results suggest a potential win-win situation,” says Mendell.
“Less summer cooling in air-conditioned buildings and less winter heating in heated buildings might reduce energy use in buildings substantially, yet have health benefits for the occupants that we did not expect.”
For further information:
Mark J. Mendell, Anna G. Mirer. Indoor Thermal Factors and Symptoms in Office Workers: Findings from the US EPA BASE Study. Indoor Air (2009), doi: 10.1111/j.1600-0668.2009.00592.x
25 February 2009