08 November 2023
Nigel Upson, Marketing Director of DK Heat Recovery, talks about the benefits of heat recovery from refrigeration and air conditioning on the road to net zero.
What is heat recovery from refrigeration (HRFR)?
HRFR is the technology that captures the waste heat from a refrigeration or air conditioning system and uses it to heat water. Heat recovery systems are NOT heat pumps and they do not use any power or to function.
How does HRFR work?
The aim of a fridge system is to move heat from where you don't want it and expel it outdoors. This expelled heat is a wasted resource that can be used to reduce carbon emissions if collected and used as a heat source. The heat can be transferred to water through high efficiency heat exchangers for use in potable water* heating or space heating. The heat exchange system is in effect a water-cooled condenser and is deployed in the hot gas line. The heated water can be used for domestic or processing use* or for space heating.
What does HRFR do for net zero?
By heating water using waste heat there is a consequent reduction in the use of other energy sources that might be used for heating water e.g., gas, electricity, oil, and therefore a reduction in carbon emissions. Based on research commissioned by DEFRA in 2016, if 15% of waste heat from food sector refrigeration were captured in this way, we would not need Sizewell C. In other words, heat recovery from refrigeration not only reduces carbon emissions but also reduces the demand for new infrastructure.
Energy gets used twice, the ultimate in energy efficiency.
What does HRFR offer financially?
The payback on heat recovery from refrigeration can be very rapid often measured in months rather than years, depending on how much hot water/heat is needed and how much duty the refrigeration / air conditioning delivers. The way in which you finance the technology can help justify it too. Upfront cash is sometimes hard to find in amongst the clamour for this investment or that repair. However, the short paybacks or the ready availability of ‘green finance' helps. There are companies which have decided to seed their net zero campaign with cash for heat recovery and used the savings to finance the rest of their programme. Very forward-thinking!
What are the barriers to the uptake of HRFR?
The most common barrier is the refrigeration engineer who doesn't fully understand the technology and fears that the refrigerant will over condense and cause the system to operate incorrectly. This is not the case with heat recovery from refrigeration as all systems are fitted with pressure controls that protect the system. The refrigeration system is always in charge of how much heat is sent to the heat recovery system.
Second is the ever-increasing rate at which freon gasses are being phased out. With the looming expectation that they will be replacing their fridge plant soon, many organisations put off considering heat recovery. The paybacks can be so short that the system will pay for itself long before the plant gets renewed. If your switch is imminent, consider heat recovery from refrigeration as an integral part of the project as the best and most cost-effective time to add a heat recovery system is when installing new fridge.
The third barrier is government policy. All we hear about is energy generation, not energy reduction. The value of energy consumption reduction has not yet really been taken on board at Westminster. There is plenty of cash for generation and carbon capture, but wouldn't it be better for the environment to fund not using energy in the first place? Interesting to note that the Minister of State for Net Zero, Graham Stuart, called heat recovery from refrigeration a ‘no brainer' when visiting a food manufacturing business in his constituency that had a newly installed unit in 2017.
The Benefit of HRFR to a refrigeration business
By viewing heat recovery from refrigeration as a business stream, forward-looking refrigeration contractors will be joining the net zero economy with consequent CSR/ESG benefits to their organisation. In addition, and more importantly, they will offer a new service to their existing clients that will save them money and help their net zero plans, without adding infrastructure. Moreover, by recognising and marketing heat recovery from refrigeration as a mainstream, all year round offering, new clients will be attracted offering business growth opportunities.
How to assess the benefits to your business
Cash: At the end of the day, any purchase has to be paid for so regardless of any other benefit, finance and ROI have to be considered. Heat recovery from refrigeration (HRFR) can offer rapid paybacks and so it is a sound investment that offers real savings in quick order, mainly because it is an add-on to existing infrastructure, not the infrastructure itself.
To establish what the potential benefits will be for your client's organisation, simply find out how much hot water or heating is used. Most grossly underestimate this figure so ask for data not just an answer. It takes 1kW of energy to heat 20 litres of water to 50°C from 10°C. If they use 1000 litres per hour at 50C that's 50kW, which at 20p per kW is £10 or £20,000 per year in an 8-hour day. A typical heat recovery from refrigeration system that delivers 50kW per hour will cost less than £25,000 fully installed.
Carbon Emissions: Per £ invested, heat recovery from refrigeration is one of the most cost-effective technologies for delivering carbon emission reductions. The same company that installed the system that Rt Hon Graham Stuart MP described as a ‘no brainer' was installed for less than 50% of the cost of solar PV installed by that same company, and delivers four times the energy i.e., £ for £ an 800% better investment. The same 50kW system and water usage as described above will save 30 tonnes of CO2 emissions per year.
ESG is increasingly high on many organisations' agendas and heat recovery from refrigeration is a low-hanging fruit for food manufacturing businesses to take a big step toward its carbon neutral goals. It is cost-effective, affordable, scalable, has a short lead time and payback and can be retrofitted with ease. Heat recovery from refrigeration is currently a little-known technology, but one that will increasingly play a part in corporate sustainability stories and can be promoted with your supply chain as a highly affordable scope 3 technology.
It takes foresighted leadership to put carbon savings before cash.
Example: Bury Black Pudding Company installed a heat recovery system in 2014 which now produces almost 10 million litres of free hot water per annum and saves the company over £34,000 based on the current Business Energy Cap. Read the case study here.
Finance, Grants and The Bank of Heat Recovery: Heat recovery from refrigeration can attract grant funding, either stand-alone or as part of a larger growth project. It can also be seen as a sustainability bank from which to borrow money for other projects due to the rapid payback it can offer. Planting some seed capital in a nominal account within your accounting system, and using the savings to fund other sustainability projects, can be a great release for justifying such expenditure, if you didn't have enough already! If the original seed was a green finance loan your capex pot is not affected.
HRFR should be on the list for investment in a net zero future, for any organisation that has refrigeration or air conditioning in its premises. HRFR is affordable, scalable easy to maintain and does not need other infrastructure for it to work.
Refrigeration companies that adopt HRFR as a business stream are well positioned to add value to their clients' business and growth to their own.
* must comply with EN 1717 so plate heat exchangers are not acceptable