Grainne McInerney - Understanding Energy Use: Retrofit and Investment

  • Positive Energy Champions: Grainne McInerney

"I aim to improve the energy usage in the Georgian quarter in a realistic way that is sustainable and economically feasible."

Owner and occupier of a building on Catherine Street in Limerick. I aim to improve the energy usage in the Georgian quarter in a realistic way that is sustainable and economically feasible for my building and hopefully share the learnings with others by trialling an option to harness waste heat energy from the ground floor café of my building and use it in the apartments above. A significant portion of buildings in Georgian Limerick have commercial units below, all of which generate heat from their operations. However, it seems that in nearly every commercial unit you see the waste energy isn’t harnessed. If this could be changed with simple technology and infrastructure, this in my view could significantly reduce energy costs for Georgian city dwellers. Researching options and monitoring over the next 20 weeks is how I hope to complete the first steps of this project.


I took part in a +CityxChange Open Innovation Call. My idea was to reuse waste heat from the café unit on the ground floor of my building to heat the cafe and the apartments above.

I installed sensors provided by the CityxChange Team into my building. These were monitored by the Project Partners IES. High temperatures were shown as expected in the kitchen. I worked with several local engineers to review heat exchange options. Unfortunately, the expert consensus was that the air from the cafe was carrying too much residue from cooking to be safely reused within a heating system economically.

I met with IES and LCCC regarding options for energy improvement in lieu of utilising heat recovery from the cafe. Several options of varying degrees were analysed. IES modelled same with their Digital Twin Tool.

I learned even shallow retrofit improvements can make a difference and have undertaken some works to date to improve it.

Through participation in the Open Call and sharing my experience, I hope it has challenged people to review opportunities even when the original idea is not successful. There are other ways to improve an older building and with the help of the Team, this was identified by the Digital Twin and analysis. My next steps are to complete further shallow retrofit options to continue to achieve potential energy and carbon reductions.


Positive Energy Champions: Grainne McInerney - Energy and Carbon Reductions 810x456

Dashboard for champions building from the Limerick Energy Model.

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Treaty Stone Limerick. Photo Piotr Machowczyk