Solstice® N40: The eco-friendly alternative to R-404A


Difisa installed a refrigeration system using Solstice® N40 (R-448a) for medium- and low-temperature rooms at the new Ascaso bakery in Huesca, Spain.

DIFISA is a company based in Spain's Aragon region. Founded in the late 1970's, the company specialises in industrial refrigeration and air conditioning. DIFISA is committed to provide the best customer service offering the greatest reliability possible when installing custom design refrigeration systems. Guided by the highest service standards, DIFISA presented Ascaso, a well-known bakery, with a bespoke solution for their new facilities in Huesca, Spain. The pastry makers moved their production to the new 1,680-m2 site equipped with state-of-the-art production equipment. However, Ascaso is keeping its artisanal touch and renowned expertise, particularly for one of their creations called the ‘pastel ruso’ (Russian cake).

Project objectives

The option selected and proposed by David Leal, CEO of DIFISA, was to install two independent units. The first installation: a low-temperature unit for the three freezer rooms, charged with R-448A, a refrigerant sold by Honeywell under the brand name Solstice® N40.
The second unit for the six zero-degree cold rooms and the work rooms charged with R-134a. This choice has a direct impact on costs and also offers the advantage of a lower GWP, ensuring that the equipment installed at the Ascaso bakery will work more efficiently in the long term.


The choice to use two different refrigerants is due to the specific characteristics of each. The first is R-134a, a refrigerant commonly used in commercial refrigeration, with very suitable properties and better operating costs for above-zero equipment. The system was designed so that, in the future, the R-134a can be replaced with a refrigerant such as Solstice® N13 (R-450A). With a 58% lower GWP and a cooling capacity only 8% to 10% lower. Switching to R-450A would reduce the impact on the environment.

The second refrigerant being used is R-448A. It is an ideal combination of low GWP and high energy efficiency - perfectly adapted to work at low temperature.

Description of the installation

The direct-expansion refrigeration system provides cooling to the freezer rooms for finished and semi-finished products, the cold storage (raw ingredients, nuts, etc.) and production rooms. Once the production is completed, products go into the blast chiller. After that, they are stored in a cold room before being sold. Humidity in the storage room for nuts and chocolates is strictly controlled and the temperature must be maintained between 12°C and 14°C.

Settings and initial results

Implementation was simple and efficient. The only operation that was a little more complex was adjusting the thermostatic valves to take into account the flow of the Solstice® N40 and to optimise the performance of the equipment. The compressors for the freezer rooms are equipped with head cooling fans. As such, no other measures had to be taken for discharge temperature.


"This was our first time working with this new refrigerant and I am pleasantly surprised with the performance of the equipment. The advice from Climalife Friogas and Honeywell was valuable help in developing this project. I am very happy with the results and we will certainly continue working together." David Leal, DIFISA.

"The project was executed well, the installation is done correctly for piping, condensate draining, insulation, and wiring. The assembly of compressors, condensers, fans, and control boxes shows high-level installation. The two systems were temporarily working at set points lower than the expected operating conditions because the equipment was not yet totally operational. These set points were then fixed when the equipment was put fully in service." Pawel Wisnik, Honeywell.

"The equipment and refrigerants were well chosen. We have found the perfect combination between sustainability and environmental friendliness. We saw the experience and professionalism of DIFISA in both the execution of the project and their advice to the customer." Jesús Gutiérrez, Major Accounts Manager, Climalife Friogas.

"As we were not familiar with the technical aspects of the project, we chose the service provider who, in our eyes, seemed the most trustworthy. With that said, we can now say that we made the right choice with DIFISA. I would like to sincerely thank them, not just for their work and the great results, but also for having teams of very genuine and professional employees. We are completely satisfied." Vicente Ascaso Martínez, Head of Ascaso.