Dr. Tony Robinson’s Fluids and Heat Transfer research group at Trinity College Dublin is currently conducting research covering a broad range of subjects that are fundamental to the science and technology of thermal energy conversion, transport and management. The primary mission of his group is to advance the state-of-the-art of thermal energy systems by developing a fundamental understanding of thermal energy transport phenomena and applying this knowledge to advanced and innovative heat exchange components, devices and technologies. These research themes specifically address those areas that underpin novel heat transfer enhancement techniques, ‘smart’ heat exchange systems and the power cost minimization of next generation heat transfer technologies found in power generation, domestic energy use, HVAC, solar collectors, space technology and high powered electronics, to name a few. On a more fundamental level, the research is currently focussed on the science and application of two-phase flow and heat transfer, enhanced liquid and gas impinging jet heat transfer, heat pipe technology, single phase convective heat transport, electrohydrodynamic enhanced thermal systems, boiling heat transfer, thermocapillary convection, thermoelectrics, energy in buildings and radiation heat transfer.

Tony’s interest in researching IR heating has developed alongside his research in energy flows in domestic building environments, in particular when it comes to the relationships, or lack thereof, between heating, comfort and energy cost. The traditional method of defining environmental thermal comfort, based on phychrometric charts with temperature and relative humidity, is diminishing in relevance as the need for efficient use of energy becomes more pressing. In residential settings one thing which is largely overlooked is the tug-of-war between the need for adequate ventilation and the need for thermal comfort. Thermal comfort is typically achieved by the brute force method of heating the air which is subsequently ventilated to the outside in order to maintain adequate indoor air quality. This is quite obviously not a sustainable approach and more elegant solutions, such as IR heating which have the potential to produce the desired comfort by directly heating the target, need to be developed and integrated into advanced energy efficient residential heating solutions. To achieve this it will not only require further R&D but also education so that people can make informed decisions about their home energy use. In the context of domestic appliances, entertainment and IT systems, aggressive R&D have developed scientific principles into technologies which are now ubiquitous. The same is not true for domestic thermal systems which have largely evolved as a trade and have thus not entertained anywhere near the same levels technological advancement over the past century.

Tony is attracted to the concept of IR heating because it is elegant, efficient and can be precisely engineered to suit a particular heating need. The brute force method of heating the whole room instead of the objects to be heated is just not logical in many instances. Even still, the design and implementation if IR heating also offers its own set of unique and interesting challenges in the context of human comfort. These challenges relate to the design of the IR heater which include, but are not limited to, (i) the focusing and/or spreading of the radiation from source to target (ii) the visible glare from the source and the conundrum that the power density drops as the wavelength increases (ii) the transient response characteristics of the heater (iv) the absorption characteristics of the target and its location relative to the heater etc. In my view, there is a very broad field for R&D in IR heater technology in the domestic environment.

The challenge is to get the balance right, in the sense that most IR comfort/space heater on the market are simply designed in the context of minimizing manufacturing cost. In my view they should be designed in the context of providing the maximum comfort (itself not easy to define) for the minimum expenditure on energy. Of course they will need to be designed for manufacture, but the only design constraints should not be target output power and cost as this is crude and will not facilitate the uptake of IR technology since the comfort issue remains open.  Some specific issues that need to be resolved include developing a deeper understanding of the human perception of heat in the context of comfort. This is an interesting challenge for IR heating considering that comfort will be related to a net exchange of thermal energy with ones surroundings. In a climate controlled environment the body will be warmer than its surroundings so that there is a net flow of energy from the body to the surroundings. The room is comfortable for an individual when this flow correctly balances the heat generated by one’s own metabolism, and this comfort zone will vary from person to person. With IR heating, the surroundings could be cooler resulting in a larger energy flow from the body but this compensated by the absorption of IR radiation, perceived as heat, and thus can strike the same balance with regard to comfort and do so intelligently and with less net energy expenditure.

To begin the design process we must first develop the capacity to characterize Infrared heaters; both experimentally and mathematically. Based on the scarce information available in the academic literature there is no scientific methodology or protocol for doing this. To this end our group has recently been researching different methodologies for 3D mapping of the radiant heat flux distribution from IR sources as well as characterizing their emissivity. The core concept of the 3D mapping strategy is very similar to that used to generate 3D velocity profiles in flowing liquids whereby a 3D positioning system is used to control and monitor the position of an appropriate sensor and the results are post processed to create 3D fields. In this research we are using advanced thermal imaging, IR thermometry, heat flux sensors as well are IR heat flux radiometers.

Near field thermal footprint of an IR heater impinging on a flat matt black surface (Enterprise Ireland-Innovation Voucher scheme funded)


This initial process is currently being concluded by Tony and his team and the model is now set to be pushed further bringing the characterisation of emissivity, emitters, architecture and materials whether human or inanimate to a point where the experimental programme and equipment to be developed will provide the data necessary to validate advanced mathematical models.

Ceramicx is excited to be working with Tony and his team and will continue to do so. The science developed by Tony and his team will help Ceramicx to develop more advanced solutions engineering while the applications brought forward by Ceramicx customers will continue to guide the engineering work of Ceramicx and the scientific work of Tony and his team.

The Team