Feature
INCREASED EFFICIENCY FROM A FREE RESOURCE
By Benjamin Brits
Heat recovery , like many aspects of the HVAC & R world , is not a new element , however its use today is on the rise as design techniques improve , and the development of up-cycling technology is driven to create ways to lower facility energy demand .
Heat recovery can simply be described as the conversion of waste heat into a useful form that can be applied to multiple applications . Its incorporation in today ’ s systems is said to be a ‘ no brainer ’ in projects as the drive for efficiency and carbon footprint reduction is attracting global pressure to accelerate ( even more so in the local context ). A little research took me back over 20 years where a number of published works already existed around the subject .
New innovative methodologies throughout the HVAC & R sectors are being developed that open up another level of efficiency as more and more clients are realising not only the importance of operational costs over the lifetime of their systems , but their moral obligations toward future generations of humanity ( and thus better use of resources ) is top of mind .
Considering the simple idea of heat recovery , integrating it into a system to actually add significant value is quite a complex matter and requires a number of considerations and calculations , much like a normal refrigeration system . Some engineers are even of the opinion that heat recovery will become so important in future that even the smallest recovery achieved will be useful in an overall system design , supplemented for example by various heat pumps and thermal storage vessels . Heat recovery units could also be installed as a retrofit on existing systems in future on the local front .
By utilising a resource that would otherwise go to waste , overall energy consumption is reduced , and therefore operational costs and environmental impact too . The process of implementing heat recovery , may in some cases , also result in smaller capacity equipment being required .
An element of many facilities , whether industrial or commercial , that is often overlooked or miscalculated when considering efficiency , is the quantity of heat generation that is actually used or required . In the local context , services are generally compartmentalised , and so there is ‘ siloed work ’
GEA Heating and Refrigeration Technologies not as common as it could be . All you need to do is look at the appointed list of professionals to any project and you will rarely find that the same company handles all of the services . Understandably , each company and engineering team will have their own methodology and preferences that then may not align to the next professional team .
In a food or beverage plant as an example , a significant amount of heat is required in the production processes . The heat that is applied to the product is then ultimately removed by the refrigeration system prior to storage or dispatch . By utilising the waste heat from the refrigeration systems and integrating the heating and cooling processes , significant opportunities are created for further efficiency . This is more difficult and could become costly as an afterthought or retrofit when opportunities are only identified far down the line in a project .
and overall facility efficiency through system integrations is Continued on page 29
An industrial heat pump with a temperature capability of up to + 95 ° C .
www . hvacronline . co . za RACA Journal I February 2022 27