Chances are, if you work in an office environment, you’re faced with the temperature dilemma: you are either too hot or too cold. This is exacerbated in an open plan office space; an environment where the aircon’s remote becomes a highly disputed weapon. And it’s all thanks to engineers!
According to renowned Australian author and science commentator, Dr Karl Kruszelnicki, the world sees 20% more air conditioning unit sales yearly.
He makes a very interesting assertion regarding the dispute over optimal office temperatures in modern day offices. He says that air conditioning units benefit men only.
He writes: “You know what I mean - the men are fine in shirt sleeves, but the women have to wear cardigans and scarves.”
Kruszelnicki chalks it up to the air conditioning standard that has been used for the last 50 years; Standard 55.
Standard 55 first made its appearance in 1966, when the American Society of Heating, Refrigeration and Air Conditioning Engineers decided to compile a long list of factors that would impact the ventilation and air conditioning of buildings.
One of the items on the checklist included the clothes that workers wear. “And you guessed it, the human they chose to base that on was a 40-year-old man, weighing 70 kilograms, and dressed in full 1960s business suit,” Kruszelnicki said. Interestingly even the metabolic rate of an individual was considered, a man’s metabolic rate.
It is well known that metabolic rates in men and women differ in most cases. It is this fact that results in women reacting differently to temperatures compared to men.
Kruszelnicki thinks that changing the indoor temperature from 22 to 25 degrees Celsius will level the playing field and empower both sexes.
Engineers are, however, working to completely redefine the game.
At the University of Colorado Boulder, Xiabo Yin and Ronggui Yang have developed a metamaterial that might change the entire HVAC industry. Working on a USD$3 million budget from the Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E), the pair created a “glass-polymer hybrid”, which was placed under a layer of silver.
They have published a journal in the Science journal. The report is entitled Scalable-manufactured randomized glass-polymer hybrid metamaterial for daytime radiative cooling.
The material can be spread out on a roof and deflect any solar radiation that it receives. The engineers say it can “cool objects under direct sunlight with zero energy and water consumption.”
The material is just a fraction thicker than aluminium foil, measuring 50 micrometers.
“Just 10 to 20 square meters of this material on a roof could nicely cool down a single-family house in summer,” said Gang Tan, an associate professor at the University of Wyoming’s Department of Civil and Architectural Engineering. The engineers add that it could also benefit thermoelectric power plants.
“We feel that this low-cost manufacturing process will be transformative for real-world applications of this radiative cooling technology,” said Xiaobo Yin, the co-director of the metamaterial research.
Furthermore, Yin commented that the material can be placed over solar panels. “Just by applying this material to the surface of a solar panel, we can cool the panel and recover an additional one to two percent of solar efficiency. That makes a big difference at scale.”
Heavy energy consumption
The metamaterial might be able to reduce more energy consumption than Australia’s proposed solar powered air conditioning units. The Department of Environment and Energy tested solar-powered air conditioning systems last year.
The Department tested different units in two categories: ‘solar thermal’ and ‘solar photovoltaic air conditioners’.
Example of a solar thermal cooling air conditioner
The hope was that the solar thermal units could become the new kid on the block and would drive down electricity bills for buildings all over Australia. However, in a report, the Department of Environment and Energy called the units a “marketing gimmick that offers no improvement in the performance or amenity of the air conditioner.”
The photovoltaic alternative proved to be inefficient too; the air conditioner only worked at 75% of its capacity.
As a result, the units in question were removed from the market. Experts are instructing consumers to buy efficient, energy saving air conditioners before putting money down on inefficient solar competitors. The technologies will inevitably improve with and costs reduce in time.
"Chill Out! Newly Engineered Material Can Cool Roofs with Zero Energy Consumption." Mechanical Engineering | University of Colorado Boulder. Web. 01 Mar. 2017.
"Freezing in the Office? It's Because Air Conditioning Standards Are Sexist." Radio National. 27 Feb. 2017. Web. 01 Mar. 2017.