Air conditioning
consumption O
HVAC key to cutting energy
role of HVAC dehumidifi ers, which remove moisture from the air to a comfortable level of dryness. The most widely accessible dehumidifi ers
Researchers all over the world are developing new forms of air conditioning to reduce our energy usage and bring carbon emissions under control. Here Neil Wright, for ADK Kooling, a London-based HVAC company, explores some of the latest innovations
ne such promising technology, being developed in Purdue University, Indiana, is a carbon-sensor system — which the
researchers believe will help to manage climate control and indoor air quality (IAQ) in huge buildings. The technology in development strongly
resembles the sensor-based lighting that most people working in large offi ce buildings will already be familiar with. When an employee steps into a room in an offi ce building, the HVAC units switch on. When they leave, they turn off . Except that it isn’t motion-sensor based. Rather, it detects the amount of carbon dioxide that is released into the air by each person, by the detection of breathing inside a certain air space on an individual level. Air conditioning is thought by many to be a human
right, but there is no escaping the fact that it is also a massive source of energy consumption all over the world. The idea is that this promising new technology will fi rst be rolled out in large buildings, and then to eventually homes. The novel technology makes use of resonant sensing and resistive sensing and will just be another component of Internet of Things (IoT) building technology, which is slowly being rolled out worldwide. And by shunning cameras for more sensitive carbon dioxide detectors, there should be little in the way for privacy concerns too.
‘Smart-window’ air conditioning
Another novel form of air conditioning in development is being worked on by Duke University in North Carolina, the United States — which could potentially cut energy usage by as much as 20% if rolled out across the country.
10 March 2022
It involves essentially a passive smart material that switches between heating and cooling with the fl ip of a switch. The researchers have described it as a “smart window-like technology” that can serve to provide both solar heating to radiative cooling. It works like this: the smart material darkens in the heating mode to absorb sunlight and prevent mid-infrared light from escaping. The darkened window-like covering then clears in the cooling mode, showing a mirror that refl ects sunlight and dissipates mid-infrared light from behind the smart material. Although this technology is extremely promising,
there are a few technological limitations at present. The prototype could only make a few hundred transitions from heating to cooling before it became ineffi cient. There is also opportunity for development in the cooling mode’s solar refl ectivity. However, as the technology develops, it may have
a wide range of uses. The eventual aim is to roll it out on exterior walls and roofs to minimise energy consumption throughout entire buildings with the technology becoming a kind of envelope or façade for buildings to passively heat and cool them. As an added bonus, by giving buildings the potential to use renewable energy for heating and cooling, it may be possible to use fewer of the construction materials that have been a major source of carbon emissions for decades.
Organic technologies
Researchers from Texas A&M University are working on an organic substance called polyimides that consumes less energy to dry air in a new study. It is the intention that these polyimide-based dehumidifi ers will one day reduce and take over the
currently use refrigerants. These chemicals dehumidify the air by chilling it and lowering its water-carrying capacity. Despite their widespread use, refrigerants are a source of greenhouse gases, which are a major contributor to global warming. Polyimides are well-known for their excellent
stiff ness and heat and chemical resistance. At the molecular level, the basic unit of these high- performance polymers is a lengthy chain of repeating, hydrophilic (meaning they absorb water) ring-shaped imide groups. But despite the fact that polyimide membranes
have shown signifi cant promise in their potential usage in dehumidifi cation there is still work to be done. A lot more refi nements are needed to increase the performance of this membrane. The technology is also still pretty expensive but is expected to come down over the years.
Radiative sky cooling
Radiative sky cooling refers to the process of capturing thermal infrared radiation from an object as it cools on the surface of the Earth. The temperature in the Earth’s atmosphere is not as consistent as it is on the ground. So radiative sky cooling technology takes advantage of the temperature variances. It traps some of the heat that would otherwise ascend into the sky from the surrounding air and transforms it into electricity. This almost fantastical sounding concept requires no electricity to operate and off ers a lot of promise for cooling buildings, automobiles, solar cells, and even thermal power plants. It has already been tried and tested, but so far has been limited to night time use only. But recently, developments have allowed some sub- ambient temperatures under direct sunlight to be experimentally observed. This technology could even one day form the basis of complementary technology to solar energy. While the power output will always be substantially lower than that of solar devices, this new technology will be able to operate at hours when solar cells cannot.
www.heatingandventilating.net
DOWNLOAD THE HVR APP NOW
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36
