Panasonic has successfully installed its CO2 condensing units in two hotels on the Spanish island of Ibiza, showing that the units can be used in applications beyond food retail in an environment that can reach very high ambient temperatures.
Benjamin Tissot, Cold Chain Key-Account Manager for Panasonic Europe, described the design, parameters, and installation of Panasonic’s CO2 condensing units in the hotels at the November 2022 ATMOsphere (ATMO) Europe Summit in Brussels, Belgium. ATMO Europe was organized by ATMOsphere, publisher of R744.com.
Ibiza is an idyllic Mediterranean island that caters to and depends on tourism. Temperatures on the island in the summer approach 32°C (90°F), with a record high temperature in September 2016 of 36.6°C (101.5°F).
Panasonic stretches the ambient temperature boundaries up to and beyond 43°C (109.4°F) with its small 1HP to 10HP CO2 condensing units, which use two-stage rotary compressors. The units can also provide evaporation temperatures as low as -45°C (-49°F), allowing for deep-freeze and blast-freezing applications. “We consider our technology so reliable in Europe, we guarantee five years on the compressor,” Tissot said.
Tissot noted that it is “always good to kill the so-called CO2 equator,” the latitude below which CO2 refrigeration is thought to be less effective due to higher ambient temperatures. “It’s good to have feedback from very challenging environments with super-high or super-low ambient temperatures and especially on a small island like Ibiza.” Panasonic also has some units running in Andalusia, Spain, with ambient temperature going up to +51°C (123.8°F) “without any constraint or problem,” he added.
Panasonic began the installation of the condensing units in the Ibiza hotels in 2019, completing it last year. Beyond the two-stage rotary compressor, the condensing units do not employ other energy-enhancing technology like adiabatic gas coolers or ejectors.
No service interruptions
The Ibiza hotels – Hotel Mare Nostrum and Hotel San Remo – wanted an environmentally friendly solution for food storage in cold rooms with improved energy efficiency. Hotel service could not be interrupted during installation so installers used a step-by-step approach to keep the motel operating as normal. Moreover, service failure would waste expensive food supplies, so units could not fail.
Finding the right solution included a detailed design stage involving local installation experts, Panasonic Spain, and Panasonic engineers in Japan. “We worked upstream on the design of the project in partnership with the installer to consider high ambient temperatures, said Tissot. “In parallel to this installation, we issued a technical document, with a list of recommendations [for] when our units are to be installed under very high – over 43°C [109°F] – and very low – under -20°C [-4°F] – ambient temperatures.” Recommendations cover a wide spectrum of components, dealing with piping, oil management, insulation, expansion valves, etc., which work with the two-stage CO2 rotary compressor to meet extreme operating conditions.
The resulting solution had the following parameters:
Hotel Mare Nostrum uses five 10HP CO2 condensing units in low- and medium-temperature evaporating conditions in an ambient temperature up to and beyond 43° C.
- Units 1 and 2 for a low-temperature cold room:, with an evaporating temperature of -30°C (-22°F) and a capacity of 8kW (2.3TR).
- Units 3 and 4 for a medium-temperature cold room with an evaporating temperature of -10°C (14°F) and a capacity of 12.4kW (3.5TR).
- Unit 5 for a medium-temperature cold room with an evaporating temperature of -7°C (19.4°F) and a capacity of 13.1 kW (3.7TR).
Hotel San Remo uses two 2HP CO2 condensing units and two 1HP units in low- and medium-temperature evaporating conditions in an ambient temperature up to and beyond 43° C.
- The 2HP units are for a low-temperature cold room with an evaporating temperature of -30°C and a capacity of 2kW (0.6TR).
- The 1HP units are for a medium-temperature cold room with an evaporating temperature of -10°C and a capacity of 12.4kW
To solve the corrosive atmosphere issues, the installation included protective coatings. The small units also reduce footprint size and noise, Tissot said.
Based on data from past installations, Tissot reported that Panasonic’s CO2 two-stage rotary compressors consume 15-20% less energy than HFC units. Additional energy savings come with the small units as the hotel can turn off and on individual compressing units based on need.
“Panasonic believes CO2 is the best refrigerant,” said Gaku Shimada, Manager, CDU Strategic Marketing Team, Cold Chain Solutions Company, Panasonic, who designed the rotary compressors and the CO2 condensing unit, and who joined Tissot on stage at ATMO Europe. “From our experiences of 20 years in Japan, this decentralized small conditioning unit is easy to install and easy to use.”
Panasonic compressors are available globally under the Panasonic brand in Europe and Asia and its Hussmann brand in the U.S., Canada, Mexico, Latin America, Australia, and New Zealand.
“Panasonic believes CO2 is the best refrigerant.”Gaku Shimada, Panasonic