In hot and humid climates, it has always been a priority of the individual to maintain some level of cooling comfort. The use of the environment, for example shading trees and ocean breezes, traditionally enabled communities to find relief from the scorching sun and as vernacular buildings evolved, elements such as open windows and wide gabled roofs, further provided areas of respite. Over time the advancement of technology saw the transition from hand held fan, to punkah, to electric fan, to air conditioner – all designed with the intention of ensuring the consumer stayed cool, comfortable and functional.
The thermal comfort expectations that consistent cooling has created, especially in highly developed nations such as Singapore, has meant that individuals are requiring and demanding cooling and greater levels of thermal comfort on a smaller, more personal microclimate scale. As one researcher declared “thermal comfort for all can only be achieved when occupants have effective control over their own thermal environment.” In conventional terms a microclimate is considered to be a distinctive climate of a small-scale area, such as a garden, a valley, part of a city or an entire town. Man made constructions such as roads, buildings and bridges as well as alteration of the landscape through agriculture or mass grading of topography can also alter natural microclimates, in many instances making them warmer, windier or more humid. But just as the outdoors has microclimates, indoor spaces can also produce microclimates, and designers are now increasingly looking to create small-scale satisfactory thermal environments for human habitation. Additional measures such as mechanical heating and cooling are now regularly employed to create optimal indoor microclimates.
One distinct trend of this climatic technology is a focus on the space surrounding the body itself. Whilst certain sustainable features, such as vertical gardens, green space and non reflective façade materials, have been developing in the last few decades to address the increasing heat levels in urban microclimates, sustainable cooling components at the scale of the individual microclimate are now beginning to appear. The reason for this is a combination of factors that include an advancing knowledge in technology, a need to provide more energy efficient cooling options and ever greater expectations of thermal comfort in our everyday spaces of work and leisure. Integrating such motives has led to the creation of a vast array of devices, ranging from heat resistant fabrics and fanned clothing, through to personal chair coolers and smart technology applications that monitor, adjust and recall temperature preferences and energy savings. Staying cool in the heat is no longer dependent on space specific cooling - bodily comfort is increasingly becoming a micro, personalised issue.
Ideally, the human body is set to maintain a temperature of 37C, regardless of the temperature of the air surrounding the individual. However, for an individual to be comfortable, especially in the heat, the air surrounding the body must be much lower – an aspect enabled or disabled largely by clothing. Traditionally in tropical regions, clothing (in a climatic capacity) was designed to assist the body to stay somewhat cool and allow for sweating and ventilation – lightweight and natural fabrics were selected based on seasonal and climatic fluctuations. The sari, for example, is designed to protect the wearer from the heat of the sun, allow ventilation via open spaces and flowing material and can provide warmth by adding additional layers or draping segments over the body differently. With the introduction of the air conditioner, the need for climate responsive clothing was no longer essential as individuals could wear western, polyester and wool garments and still maintain ideal thermal comfort levels. From an energy consumption point of view, this may be deemed highly wasteful. Another outcome of mechanical ventilation is the reliance on cooling it encourages, perpetuating an expectation of thermal comfort in outdoor spaces, transitory environments and places unable to access air conditioning. To compensate for such thermal expectations and maintain a level of comfort and energy efficiency, designers have been inventing a number of practical clothing options for the individual. Some examples include:
- The RPCM cooling vest (just one example from a large market of cool vests), is made from high technology processed fats and oils, maintains a consistent 15C for up to 2.5 hours, and can be recharged via placement in cool water for 15 minutes, time and time again. The cooling vest is utilised by those working in industrial and manufacturing work, defence services or even for recreational purposes
- Cornell University Design students have produced sportswear that turns white when an athlete is overheating, as a means of allowing the individual to control their own thermal comfort levels
- Nike are constantly experimenting and testing the thermal comfort characteristics of their textile materials and apparel designs via sweating thermal manikin systems
- The US Department of Energy’s Advanced Research Projects agency is developing a line of ‘smart clothing’ that keeps the wearers skin at 93 degrees Fahrenheit by adapting to temperature changes in the room – ultimately the fabric will get thinner as the room gets warmer, and vice versa
- Dhama Innovations have produced a line of clothing that features a form of thermoelectric technology, similar to that in laptops, to both heat and cool the clothing via a rechargeable battery. Controlled by the wearer and consisting of eight temperatures, the clothing can be used in both hot and cold climates
- And in Japan, design company Kuchofuku have invented an air conditioned work jacket (amongst many other items), that incorporates a dual battery powered fan to keep the inside of the garment cool
Clothing inventions such as these make it possible for people to maintain an ideal level of thermal comfort, in any context, whilst also removing themselves away from a dependence on energy consuming cooling devices such as air conditioning. Placing the power to control thermal comfort levels, a largely subjective ideal, within the hands of the individual via elements such as garments, alleviates the stress of interior spaces or larger areas having to meet mass comfort expectations – instead each individual sets their own microclimate, a capability that may become even more necessary as temperatures increase. Addressing the most intimate and consistent level of the individuals microclimate, that of clothing, is a most constructive method in helping people to achieve optimum comfort levels whilst also encouraging more sustainable cooling regimes.
Clothing is only one example of the way cooling is changing on the personal microclimate level – furniture and home appliances are also adapting to suit the comfort levels of inhabitants. In the tropics, furniture was for the most part made from local materials such as wood and rattan. Designed to allow for ventilation and to withstand the humidity, furniture such as chairs, lounges and beds were climate suitable and appropriate for both indoor and outdoor conditions. Again with the introduction of air conditioning, western ideals of furniture and interiors filtered through to other parts of the world – heavy woollen and leather furnishings, thick doonas/duvets/comforters and cushions, and items vulnerable to damage from humidity. Regardless of the heat building effect many of these items bring to the household, individuals can overcome the discomfort via high levels of mechanical cooling, a choice that both propagates thermal comfort expectations and leads to unsustainable behaviours.
As a way of combining thermal comfort, energy efficiency and desired interior designs of home owners, a number of items have been developed for the home and office space. Just like with clothing, the technology in producing fabrics for furnishings has adjusted to provide optimum comfort levels. For example, fabric designers Outlast have produced materials that absorb excess heat, store it and release it back into the fabric when necessary – reducing sweating and heat absorption and applicable to chairs, couches, outdoor settings, car seat covers and even bedding. Similarly, brand ELMOCOOL have created a type of leather that utitlises TFL Cool System technology – a system that inserts cool pigments into the surface that allow for heat to pass through and be reflected, rather than be absorbed, ultimately reducing dark leather coverings by up to 20C when in direct sunlight. Fan systems have also been employed to keep furniture cool, including the Bedfan Cooling System that provides cool breezes underneath the bottom sheet and has a speed controller or the Air Cool Cushion AC Adapter Set that can be used on office chairs, whereby moisture and heat is cooled via a urethane spacer material in the cushion. Both guarantee cool comfort, controlled by the individual and long lasting to ensure consistent cooling as needs be.
Completely different again is the zero energy table (soon to be an entire range of furniture), designed by Menard and Lagrange. Made from solid oak with a corrugated anodised aluminium underside, the table absorbs excess heat when the room exceeds a temperature of 22 degrees via phase change material (PCM) wax. When the room cools down again, the wax solidifies and releases heat back into the room. All three examples demonstrate the lengths designers have gone to create relationships between humans and things, with a purpose of comfort building. The interaction between the two allows for objects to provide the comfort, rather than the space surrounding them – a far more controllable and sustainable way to meet subjective thermal expectations of an individual's microclimate. Further advances in this field could possibly even lead to the demise of energy consuming mechanical cooling devices – a move that would shift the ways of cooling even more dramatically into the hands of the individual.
Innovation in the cooling industry has opened up a huge number of opportunities for individual comfort control in parallel with ever greater expectations of constant comfort. Whilst air conditioning has traditionally been restricted to indoor environments, set to a temperature that provides an average level of comfort to an average number of people, new developments are letting people control their own preferred temperature, regardless of where they may be. One such device is the Wristify – a prototype wearable device for your wrist that makes you feel cooler by reducing your temperature a few fractions of a degree per second, eventually after a few minutes causing you to perceive your entire body as cooler. As the MIT student developers themselves state “if everybody had one of these things on their wrist instead of relying on air conditioning or heaters all the time, the potential energy savings could be massive.” From the small scale to the large, in 2014 the Singapore Sports Hub implemented the first of its kind, individual seat cooling system. Delivering mechanical air (powered by solar energy) to the areas only being used by people, the system decreases the amount of air needing to be cooled and cuts energy use by 60% compared to stadiums of a similar size. Although not controlled by the participant, the individual cooling device in an outdoor setting provides a higher degree of comfort, than if it was to be simply an air conditioned space, whilst also meeting thermal comfort expectations in an exterior environment. Running parallel to this newfound control of personal thermal temperature is the apparent energy savings made possible by individual cooling devices, perhaps of most benefit to those living in high density artificial cooled environments. With the availability of personal cooling apparatus still in early development, the current burgeoning market of air-conditioning responsive smart-tech cooling apps continues to change the way people are able to experience more personalised and sustainable indoor cooling.
In the 1960s, P. Ole Fanger created a predictive model for thermal comfort – a method whereby heating and cooling engineers could predict, for any type of activity or clothing, all the combinations of thermal factors in the environment for which the largest number of people in a group would experience ideal thermal comfort. As a result, Fanger’s theory became the global model for predicted thermal perception of building occupants, and reinforced the necessity of air conditioning in warm climates. With the advancement of mechanical cooling and their increase in availability, especially in the late twentieth century, air conditioning numbers continued to rise. In fact, the air conditioner is so popular, that in America, air conditioning energy consumption doubled in only 12 years, and in China ownership rose from 8% to 70% between 1995 and 2004. For many people now, air conditioning is more than simply a relief from heat, it is a proviso for optional thermal comfort. However, the argument remains, for people to truly be comfortable, regardless of Fanger’s method, people need to be able to control their own microclimate – a notion that has seen the investments in cooling smart technology grow rapidly in the last decade or so. Smart technology allows for consumers to control their environment (in this case the air conditioned environment) in far more detail – connected 24/7 to the control panel, air conditioner owners can now access usage information, change temperatures of different rooms, set location sensors to turn the device on or off and monitor efficiency, all via their smart phones at any time they wish. The scope of control becomes even more micro and defined, again highlighting the idea that cooling now can relate directly to the individual, not the space. A burgeoning sector, the cooling smart technology market now offers a huge variety of options for home and business owners, some examples include:
- Tado: A device that connects to your pre-existing air conditioner and can be controlled remotely by the smartphone app Tado Cooling. Able to track your location via your phone, the device turns on the AC before you reach your house, monitors your movements inside the home to deter which rooms to cool first and checks the weather forecast to determine when is best to let the natural environment take control – ultimately saving up to 40% of AC costs.
- The NEST: Like the Tado, the Nest can be remotely controlled from your phone and align with most pre-existing heating and cooling devices. In addition to this, the Nest thermostat learns the occupants’ routines and their preferences for temperatures and builds a personalised schedule for the home, making it far more efficient and applicable to each individual household. Furthermore, the device notifies the occupants when they’re saving energy, encouraging the dwellers to minimise their usage.
- The Honeywell Prestige HD: Unlike the Tado and the Nest, the Honeywell has a visible control pad that you can program temperature, air quality and humidity levels for individual days and for individual rooms (each day and room can be different). Whilst not intuitively adaptable like the others, the control pad allows homeowners to specifically control their thermal comfort levels, according to the space they’re in. Additionally, using outdoor sensors, the thermostat will detect and display the external temperature and humidity levels so the individual can program their day in response to the exterior.
These examples demonstrate that smart technology has made it possible for people to control their thermal comfort levels according to their needs and expectations, rather than the space determining the levels of possible comfort. Individual control over the temperature, the space being cooled and the times and locations at which it is done (as well as the additional assistance in terms of outdoor weather monitoring and energy consumption readings), helps to reduce the absolute need for generalised cooling, and instead creates a smaller interior microclimate for the household (or even on room level) that is far more efficient, subjective and overall comfortable. Running parallel to this is the energy savings – the main reason for integrating electronic systems into mechanical ventilation apparatus. By lessening the time the air conditioning is on (ie via remote temperature control), the space it needs to cool, and the ability for the individual to view their usage and subsequently their savings, all leads to better consumption rates and far more energy efficient operations. Thus the benefit to changing the nature of cooling to smaller spaces – or the personal microclimate – delves into a number of areas, producing a dynamic thermal comfort zone for each individual.
The ways of cooling have most definitely shifted over time, and most certainly will continue to do so as technology advances and the world continues to heat up. Now that air conditioning is ingrained within the functioning and thermal comfort expectations of large swaths of the global population, various measures, such as those mentioned here, are providing alternative ways for people to control their own comfort, whilst simultaneously help the environment. Clothing, fabric, furniture, gadgets and smart technology have all adapted in an attempt to relieve peoples’ dependence on artificial cooling and instead offer people the opportunity to shape their own independent thermal microclimate and ideal level of comfort. Greater control of the personal microclimate tends to go hand in hand with the cooling of smaller spaces, a measure that has seen energy consumption decrease in the form of mechanical cooling – an achievement that might even one day lead to the demise of the air conditioner all together? Thermal comfort expectations are no longer linked solely to the overall set temperature of the air conditioned space of the interior – devices used in transit, remote controlled smart technology and personalised cooling objects have all created a new expectation of thermal cooling. It is a trend that will no doubt benefit the individual, but at the same an increasing reliance on artificial means for maintaining comfort raises important questions about energy consumption and the environment.