The planet is now about 1.1 degrees Celsius warmer on average than in the 1800s. The effects of higher temperatures have been seen worldwide, with 2022 being one of the hottest years recorded. Some climatic changes such as droughts, heat waves, wildfires, and extreme rainfall are happening faster than scientists previously predicted.

While the temperature increases, it’s ironic that the technology required to keep our homes and workplaces cool only makes the climate even hotter. Studies have pointed out that the increasing need to cool the air is both a cause and effect of climate change. Today, ACs have moved from a luxury to an essential in many homes. In the next 30 years, it is estimated that air conditioners would become as common as cell phones are today. The World Economic Forum forecasts that by the end of the century, greenhouse gas emissions from ACs will be responsible for as much as 0.5 degrees Celsius rise in global temperatures.

As part of a study, researchers measured the impact of climate change on AC energy use by 2050. The report projects an increase of nearly 14% in the warmer climates that were studied ( such as Chennai, India) and air conditioner energy use to increase by 41% in the milder climates (such as Milan, Italy). Reportedly, the substantial increase in global humidity would have a larger impact on greenhouse emissions than the incremental increase in global temperatures.

In other words, we need to relook at how air conditioning works. The fundamental technology behind air conditioning and refrigeration has remained the same since it was first invented. In 1902, Willis Carrier invented the AC to address humidity issues faced by a printing company in New York City. Since then, refrigerators and ACs have grown into everyday necessity. In countries with younger populations and bustling economies such as India, Brazil, and Indonesia, billions would soon purchase their first home air conditioner. For instance, the household ownership of ACs in India today is a mere 7%, and the demand for comfort cooling is expected to drive the total stock of room ACs to over 1 billion by 2050 – a 40-fold growth from 2016. The air conditioners purchased and their effects on the environment become a crucial decision for the rest of the world.  

Companies across the world are trying to reduce the impact on the environment through ACs. Much investment has gone into R&D to help incremental changes in the AC functioning. Companies have worked out many options such as increasing AC efficiency, using lower environmental impact refrigerants, use of heat pump technology, and even the reclamation and destruction of fluorocarbons through the AC product life cycle. While we move towards more efficient systems, the planet requires a transformational change in air conditioning efficiency with different approaches.

Amongst the many innovations that have come to the fore, one is the hot water AC developed by Chilton Refrigerators. The hot water AC utilizes the outdoor unit of an AC to generate hot water. The system uses the redundant heat produced during the cooling process to heat water. Thus, one AC unit serves the dual purpose of providing cool air and hot water. The heat dissipated by the condenser is usually released into the environment, adding to greenhouse emissions. Researchers have calculated air conditioning is responsible for nearly 3.94% of global greenhouse gas emissions, with almost 1,950 million tons of carbon dioxide released annually. Of that, 27% comes from the energy used to control the temperature, and a comparable 30% is used to remove humidity.

In the hot water AC, the heat released by the condenser is utilized to heat water, which is another everyday need in many households. The condenser in the system gets cooled both by water and by air, resulting in double condensation, thereby enhancing cooling efficiency while lowering power consumption. This further helps to reduce the carbon footprint of AC units. The hot water AC is of significance in warm and cold climate regions. For instance, in Europe, which has a relatively cold climate, space and water heaters account for more than 80% of household energy consumption. The hot water AC is also significant in many industries that require the continuous running of ACs and refrigerants, along with the need for hot water. Industries like hotels, holiday resorts, spas, and saloons, office buildings can benefit from the hot water AC.

The production of hot water is achieved by transferring waste heat from the condenser to the water in the tank using a specially designed stainless steel heat exchanger, which requires no additional power/electricity requirements. The Chilton Dual Purpose AC (DP-AC) uses a stainless-steel heat exchanger, which ensures that the water can be used for drinking and cooking purposes (dependent on the water quality). The hot water is stored in a highly insulated system such that it can also be ready for use the next day.

The hot water AC thus nullifies the heat given out by the AC unit. In return, it also reduces the power consumed in heating water, by providing free hot water from a running AC unit. Moreover, the double condensation unit ensures better cooling efficiency and lower electricity consumption.

When the many benefits of a hot water AC are brought together, it significantly reduces the Global Warming Potential (GWP) of the air conditioner. Researchers have shown that hot water ACs can lead to a 53% reduction in GWP as well as a reduction in carbon footprint by 10476 kg per unit per year. This innovation could be the outset of larger, more positive changes in the refrigeration and cooling industry.

The hot water AC positively impacts the environment by lowering greenhouse emissions, and carbon footprint and drastically lowering climate change. The significance of hot water ACs will be dependent on the scale of use and patronage. While the global impact of such dual-purpose, energy-efficient systems would take time to realize, an immediate impact would be felt with lower urban heat islands in cities and towns around the world.