Heat and cooling
INNOVATION
US warms to thermal cooling projects I n recognition of the pressing need to improve energy efficiency performance in residential and commercial buildings, the DOE’s Building Technologies Office recently awarded a total of $83mn in funding to 44 projects under the auspices of its Buildings Energy Efficiency Frontiers & Innovation Technologies (BENEFIT) programme. Several of the projects focus on the development of innovative thermal cooling and sustainable air conditioning technologies. One notable initiative is a project led by Delaware-based Baryon Inc. The firm is developing a novel air conditioning system based on a new method of evaporative cooling combined with dehumidification through an innovative ionic membrane. As Demis Pandelidis, Founding Director at Baryon Inc, and inventor of the system, explains, the new technology utilises some of the principles of evaporative cooling, but: ‘works in a completely different airflow regime which, combined with membrane dehumidification, allows it to achieve high effectiveness in humid climates.’ Crucially, Pandelidis points out that the system also enables the same ‘comfort of use’ as traditional systems – including the same level of temperature control and thermal comfort, regardless of outdoor conditions. ‘The proposed unit achieves a coefficient of performance (COP) on the level of 12.5 in humid climatic conditions, which allows it to save 50–80% more energy in comparison to existing devices. It also has a simple plug-and-play structure that can be easily installed in any building and allows for independent temperature and humidity control,’ he says. ‘The additional benefit is that our unit produces water for its operation, meaning there is no external water consumption. This is a critical factor in many of the world’s regions and we are happy that we can meet this goal,’ he adds.
20 Energy World | October 2021
The US Department of Energy is funding a range of projects to develop innovative energy efficiency solutions for residential and commercial buildings – several of which focus on thermal cooling. Andrew Williams takes a look.
Visualisation of Bayron’s air conditioning system based on evaporative cooling and dehumidification Photo: Bayron
Functional prototype The project aims to create the first energy saving solution for air conditioning systems in humid climates. Although many novel renewable energy-based devices have been implemented for heating purposes over the last two decades – including heat recovery units, heat pumps and solar PV systems – Pandelidis points out that no devices based on renewable energy have been widely applied in the cooling sector. Although direct and indirect evaporative air-cooling technologies enable users to save energy in specific applications in dry climates, Pandelidis notes that their effectiveness drops significantly in moderate and humid climates – and they are not able to maintain comfortable conditions inside buildings in humid climates. ‘Most of the global human population lives in humid climates – with East and Southeast Asia, most states of USA, excluding central states like Nevada or Arizona, southern Europe and Africa all characterised by humid
conditions in summer. For this reason, evaporative cooling can’t be widely applied and is only used in selected dry regions, like central parts of the US, as well as Australia and the Middle East,’ he says. ‘In addition, they consume high amounts of water, which is problematic in many regions with limited water supply – for example, in California. They also have fixed, large dimensions and lack temperature control capabilities because they are passive and their effectiveness depends on the ambient air conditions.’ In an effort to address these shortcomings, Pandelidis reveals that the goal of the Baryon project is to overcome all of the disadvantages of traditional evaporative cooling and take cooling technology to a completely new level. Building on earlier work to prove the principles of the technology at the laboratory and numerical level, the project will develop and install a fully functional prototype – verified by both the Argonne and Oak Ridge National Labs – that will serve as a base for mass production. According to Pandelidis, a key
US cooling market The US cooling market is one of the biggest on the planet – second only to the Chinese market – and demand for air conditioning in the country is expected to triple before 2050, according to Pandelidis. ‘Increasing demand for cooling is combined with the increasing cost of operation of air conditioning equipment because of the constantly rising price of electricity. Due to this fact, the need for energy saving solutions will continue to grow,’ he says. In concrete terms, Bacellar reveals that the US HVAC market is currently worth approximately $15bn a year – with commercial HVAC accounting for nearly 30% of the market. It is expected to grow by 6% by the end of the decade, while energy use for space cooling worldwide may increase three-fold by 2050. ‘Growing electrification – for example with electric vehicles and heat pumps for space and water heating – in combination with growing population and wealth around the world, means we will need to power all that more efficiently,’ he says. ‘Cooling and heating are responsible for nearly 7% of greenhouse gas emissions, but with the warming climate it may take a larger portion in the future,’ Bacellar adds. ‘Energy efficiency is the first, most important step towards sustainability, followed by technologies that enable a reliable use of renewable energy, such as storage. Heat pumps and thermal batteries are likely key players in the years to come in the HVAC world.’
