Hydrocarbon Free Refrigeration System

ADA is a leading engineering and design firm that specializes in creating sustainable building projects. Recently, they were approached by a client who wanted to design a new 40,000 sq./ft retail outlet that would be a sustainable store project. The client was committed to building an environmentally friendly store that would not use natural gas for heating. The challenge was to create a refrigeration system that would be a full natural refrigerant solution, capable of providing heat recovery for either water or air in place of boilers. The project also required an ultra-low GWP heating system capable of delivering around 400kw of heat to air handlers for distribution around the shop.

Problem:

The project had several challenges that needed to be addressed. The first issue was to design a refrigeration system that did not use hydrocarbon refrigerants that were prohibited by the client’s insurers. The second problem was that ground source heat pumps were not suitable due to land subsidence issues with the site.

Solution:

After careful consideration of the client’s requirements, ADA designed and proposed a solution that would meet the project’s goals while remaining cost-effective. They decided to use two dual-temperature DX CO2 Booster packs, complete with heat recovery plates which enable the waste heat from the refrigeration proces to be utilised. The use of these packs would guarantee a completely natural refrigerant solution for the client’s refrigeration system, fulfilling one of their primary requirements. Moreover, two external air-source heat pumps were employed to make use of waste heat by interfacing with the main packs through a plate heat exchanger. Load cells were installed on the heat pumps to ensure that heating requirements for air heating were met consistently throughout the year.

The use of DX CO2 packs was an excellent choice as they are an eco-friendly solution that has a low global warming potential (GWP) compared to other refrigerants. The heat recovery plates on the DX CO2 packs allowed the system to recover excess heat and provide it for heating requirements. The external air-source heat pumps were also a great solution, as they provided an ultra-low GWP heating system capable of delivering the required heat to air handlers. By combining the two systems, ADA was able to achieve the client’s ESG brief, satisfy the building insurers, and deliver the project on budget.

Result:

The client was able to achieve their goal of creating a sustainable store project that did not use natural gas for heating. By using the DX CO2 packs and external air-source heat pumps, ADA was able to provide an eco-friendly solution that met all of the client’s requirements. The project was completed on time and on budget, and the store was entirely free of natural gas heating, all with a COP of above 4.0.