In an era where sustainability and energy efficiency are not just buzzwords but essential requirements, laboratories around the world are facing the challenge of minimizing their environmental footprint. Ultra-low temperature freezers (ULT freezers) in particular, which operate continuously at -80 °C, are known for their high energy consumption. However, technological innovations and growing environmental awareness are leading to a new generation of appliances that not only store samples safely, but also drastically reduce energy consumption. This article looks at the latest developments in energy-efficient ULT freezers and compares leading models in terms of their energy savings and sustainability features.
Technological classification of current ULT systems
There are many modern suppliers of deep-freeze systems vying for a permanent place in the laboratories of the life science world. The market is characterized by a colourful mix of established manufacturers with decades of experience and young challengers with fresh concepts. These devices are key tools in research, biobank logistics and pharmaceutical development - and yet, rarely does anyone really take a close look at what is going on under the hood.
One thing is clear: the requirements for ULT freezers are increasing - not only in terms of storage capacity or temperature stability, but increasingly also in terms of energy efficiency and ecological compatibility. The issue of energy consumption is no longer a "nice to have", but a measurable decision criterion, especially in light of the drastically tightened F-Gas Regulation, which will unleash a new wave of regulatory pressure in 2025. (Newsfeed on F-gas regulation)
In this analysis, we deliberately focus on the most widespread technical model on the market: the cascade system. It forms the backbone of the ULT world. We have left out other approaches - such as the DualCool system with two separate cooling circuits. Not because they are irrelevant, but because we are concentrating on the cascade system for better comparability. Other cooling concepts, such as the piston principle, are deliberately left out completely because they have simply not achieved any significant market presence.
A look at the market reveals the familiar big names: Eppendorf, Thermo Fisher and PHCbi have been shaping the image of established suppliers for years. However, new competitors are growing up in their shadow - especially from Asia. Haier, for example, is no longer a pure price competitor. The company is making targeted investments in technology, expanding its service networks and is thus also gaining a higher profile in the European market, making it part of our comparison.
For our evaluation, we take ULT freezers with a working volume of around 700 liters as an example and focus on the use of green refrigerants - because this is the only way to truly compare performance and sustainability. Let's start with a look at the technology behind the energy efficiency.
Energy efficiency put to the test
In an industry where energy consumption and sustainability are not only cost factors but also image factors, it is no longer enough to rely on data sheets. Today, energy efficiency means more than just a low consumption value in the brochure - it is the result of several interrelated parameters. In order to enable a realistic and practical assessment, in this chapter we look at four central technical criteria - assuming a typical small machine fleet of five ULT freezers. The upward scalability must be explicitly taken into account: With each additional device, the effects on energy consumption, indoor climate and operational safety increase significantly.
Power consumption of ULT freezers
Pure energy consumption in kWh/day is still an obvious starting point for evaluating efficiency. This is because in practice, appliances with a similar design can have drastically different values - depending on the compressor type, insulation concept, door seal and control technology.
With a fleet of five machines, the difference between an efficient and an outdated model can quickly amount to several thousand kilowatt hours per year. Power consumption is therefore not just a technical parameter, but a tangible economic lever - especially with rising energy prices.
The heat dissipation of ULT freezers into the room
A large proportion of the energy that flows into an appliance is inevitably released as heat - and this heat ends up in the laboratory. The result: an additional load on the room air conditioning, which can sometimes amount to 30 % of the original freezer consumption.
This point becomes more important with the number of appliances. With five appliances, the effect is clearly noticeable - with ten appliances, heat dissipation quickly becomes a major infrastructural issue. The more efficient not only the appliance, but also its integration into the room concept, the more sustainable the entire solution.
Maintainability & reliability
Energy efficiency must not be a maintenance nightmare. With green refrigerants in particular, access to components and the availability of service partners are crucial. A device that is "only efficient in the lab" quickly loses its advantage if replacement parts take weeks to arrive or the technician is at a loss.
Some providers rely on modular components and clearly structured diagnostic options. This reduces downtimes and increases ease of maintenance. At the same time, the training requirements for technicians are reduced - a point that becomes much more important as the number of devices increases.
An appliance that works efficiently but breaks down frequently is a bad deal. Actual reliability in continuous operation - below -80 °C - is therefore perhaps the most important factor of all. After all, an unexpected failure can not only jeopardize operating costs, but also entire research projects.
A good efficiency assessment must therefore also include the mean time between failure (MTBF) and the availability of spare parts. It is particularly worth considering replacement strategies and service level agreements as part of the overall concept when there are five or more devices.
Then let's take a look at the figures - and get straight into the first chapter: power consumption of the actual devices.
The power consumption of the ULT freezers
Specifically: We took a look at the websites of the leading manufacturers (as of May 2025) and selected the current top model with cascade technology, a usable volume of around 700 liters and environmentally friendly refrigerant - the aim: a comparison that is as objective and transparent as possible without artificially inflated differences.
It is important to understand that the stated energy consumption is always measured under defined test conditions. Manufacturers specify both the room temperature (RT) and the target temperature in the interior - usually -80 °C, occasionally also -70 °C. These two parameters have a significant influence on power consumption: lower room temperatures reduce the load on the cooling units, while warmer conditions significantly increase the energy requirement.
For this reason, in addition to energy consumption, our overview also lists the room and target temperatures defined by the manufacturer:
The candidates
| Model | Manufacturer | Useful volume (L) | Energy consumption (kWh/day) | defined RT / set temp. | Refrigerant | Certification |
| CryoCube F740Hi | Eppendorf | 740 | 10.5 | 20°C / -80°C | R290/R170 | ENERGY STAR® |
| TSX50086FA | Thermo Fisher | 682 | 7.8 | 20°C / -80°C | R290/R170 | ACT, ENERGY STAR® |
| DW-86L729BP | Haier | 729 | 8 | n.a. / n.a. | R290/R170 | ENERGY STAR® |
| MDF-DU703VH-PE | PHCbi | 729 | 5.4 | 23°C / -80°C | R290/R170 | RoHS, ENERGY STAR® |
(Source of energy consumption: ENERGY STAR)
This creates transparency about the test conditions without "correcting" the values mathematically. As this would simply be too time-consuming and we do not want to change the manufacturers' data, even if cooler test environments lead to lower consumption values, these are laboratory conditions, not realistic usage scenarios. Nevertheless, the data can serve as a guide to better classify the values.
Unfortunately, we do not have any specific information from Haier on the measurement conditions. This makes the detailed consumption data from PHCbi, which is an important reference model with the highest RT, all the more valuable.
Classification of the ENERGY STAR label
Open details
ENERGY STAR is an international energy efficiency label that was originally created by the US Environmental Protection Agency (EPA ). It identifies appliances that operate with above-average energy efficiency - i.e. consume less electricity than the market average for comparable performance.
The label is regarded worldwide as a reliable and independent seal of approval for laboratory equipment, refrigerators, computers, lighting and office equipment, among other things.
Why is ENERGY STAR particularly relevant for ULT freezers?
- Participation is voluntary, but tested - this creates trust.
- ULT freezers run 24 hours a day, 365 days a year - so power consumption is crucial.
- ENERGY STAR-certified freezers meet strict requirements for energy efficiency, cooling performance and standby consumption.
The resulting energy balance for 5 appliances / year:
| Model | Annual energy consumption (kWh) | Annual electricity costs (0.29 / kWh) |
| CryoCube F740Hi | 19'162.5 | 5'557.10 CHF |
| TSX50086FA | 14'235.0 | 4'128.15 CHF |
| DW-86L729BP | 14'600.0 | 4'234.00 CHF |
| MDF-DU703VH-PE | 9855.0 | 2'857.95 CHF |
Conclusion: Energy is (only) half the truth
If one considers the realistic operation of a small fleet of 5 devices and assumes an average electricity price of CHF 29 centimes/kWh (as of May 2025), there are significant differences in the annual operating costs.
→ The savings potential of the smallest consumer compared to the largest consumer is around CHF 2,699 per year and vehicle fleet - purely through electricity.
But energy is only one of several influencing factors. In the next chapter, we show how heat dissipation, ease of servicing, reliability and suitability for thermosensitive samples have a decisive influence on the overall picture - and how to make a sustainable long-term decision that is not only economical but also ecologically sound
The heat output of ULT freezers
Wherever electricity flows, heat is generated - especially in devices that operate at -86 °C day and night. Ultra-low temperature freezers (ULTs) are among the largest internal "radiators" in laboratories, even when they freeze. The waste heat emitted not only pollutes the ambient air, but also forces the air conditioning in research facilities to constantly work harder. And that costs - not only electricity, but also technology and well-being in the long term.
The aim of this chapter is to quantify the heat load of the four compared models, calculate the additional cooling effort (with a typical COP of 3.3*) and show the hidden operating costs caused by energy-hungry freezers.
What is the COP ( Coefficient of Performance)
Open details
The coefficient of performance, or COP for short, describes the efficiency of a cooling system. It indicates how much thermal energy (in kWh) a cooling system can dissipate with one kilowatt hour of electrical energy.
* A COP of 3.3 means:
- For 1 kWh of electricity, the system can remove 3.3 kWh of heat from a room.
Or the other way round:
- To dissipate 1 kWh of heat, you need approx. 0.3 kWh of electricity (because 1 ÷ 3.3 ≈ 0.303).
Why this is important:
The waste heat from a ULT freezer becomes an additional load for cooling the room. The higher the COP, the more efficiently this heat can be removed - which has a direct impact on electricity consumption and cooling costs. A typical COP of modern split or precision cooling systems in laboratories is between 3 and 4 - we conservatively calculate with 3.3 as a realistic assumption).
Heat balance and air conditioning costs in comparison
| Model | Waste heat per year (kWh) | Additional cooling requirement (kWh / year) | Cooling costs at 0.29 CHF / kWh |
| CryoCube F740Hi | 19'162.5 | 5'748 | 1'666.90 |
| TSX50086FA | 14'235.0 | 4'270 | 1'238.40 |
| DW-86L729BP | 14'600.0 | 4'380 | 1'270.20 |
| MDF-DU-703VH-PE | 9'855.0 | 2'957 | 857.60 |
Conclusion: heat load is not a side issue
Choosing a more efficient freezer not only reduces direct electricity costs, but also indirect costs due to the lower heat load. With 5 appliances, the difference in additional cooling costs adds up:
- CHF 809.30 per year between Eppendorf and PHCbi
- CHF 380.80 per year between Thermo Fisher and PHCbi
- CHF 412.60 per year between Haier and PHCbi
An economical freezer not only reduces the load on the energy supplier, but also on the HVAC system. Fewer running compressors, lower temperature peaks and a more constant room climate are concrete advantages in everyday life - especially in confined laboratory spaces or where there is a combined heat load from equipment parks.
Maintenance safety & reliability
As we only look after PHC systems in active service, we cannot make any detailed statements about the maintenance practices of other manufacturers - but what we can say with certainty: PHC impresses with its consistency, quality and long-term support.
When it comes to maintenance safety and reliability, we deliberately focus on PHCbi, as we have been working with this brand for many years as a supporting partner and know its quality first-hand. No other manufacturer in our portfolio is serviced and supported as consistently as PHC - this creates a reliable verdict from practical experience.
PHCbi (formerly Panasonic Biomedical) has been active in the field of ultra-low temperature technology for several decades and has established itself as a major player worldwide, particularly in Switzerland. This long-standing market presence is a strong indication of product safety and service reliability.
As a Japanese manufacturer, PHCbi stands for technical thoroughness, long-term stability and precision. Our own maintenance experience confirms this: The appliances have an extremely low susceptibility to faults, the maintenance intervals are long and the spare parts supply is excellent - even for older models. In combination with forward-looking product maintenance and compatible generations, this makes the PHC a strategically safe choice for laboratories that rely on long-term operational stability.
"I have been working with PHC appliances for over 20 years and am always impressed by their quality and durability. The precision with which the Japanese design and test their freezers is truly remarkable."
Armando Paradiso, refrigeration engineer VITARIS
Who is PHCbi
Origin and development
PHC Holdings Corporation (PHCHD) is a Japanese provider of medical devices and healthcare solutions headquartered in Tokyo. The company was originally founded in 1966 as SANYO Electric Biomedical Division. In 2012, SANYO was acquired by Panasonic, whereby the well-known ultra-low temperature freezers were temporarily marketed under the name Panasonic Biomedical. Since 2018, the company has been operating under the independent name PHC Holdings Corporation.
PHC has since developed strategically and now operates as a global technology group specializing in laboratory, diagnostic and digital health solutions. The company is active in over 125 countries and employs around 9,200 people worldwide.
Research & Strategy
PHC consistently invests in research and development: In 2023, around 6.3 billion yen (~CHF 38 million) was invested in innovation projects, particularly in the areas of life science, diagnostics and diabetes management. The company is listed on the Tokyo Stock Exchange and is backed by KKR, Mitsui, Panasonic and L Catterton, among others - a clear indication of its long-term strategic focus and technological substance.
This culture of innovation is also reflected in the continuous development of ultra-low temperature freezers (ULT freezers). For decades, PHCbi has been focusing on technological advances with a focus on energy efficiency, reliability and sustainability:
- Back in 1993, PHC (then still known as SANYO) was the first manufacturer to introduce environmentally friendly refrigerants in its ULT freezers.
- In 1995, the company was honored with the EPA Stratospheric Ozone Protection Award for its pioneering work.
- The model series began with the MDF-U71V with an energy consumption of 21.4 kWh/day, followed by gradual optimizations in the successor models.
- A clear trend can be seen across the generations U74V (18.3 kWh), U76V (13.5 kWh) and the VIP ECO series (DU702VH: 7.7 kWh, DU703VH: 5.4 kWh): each new generation has significantly improved energy efficiency.
This technological line is the result of consistent R&D work: from more efficient cascade compressors and patented VIP vacuum insulation to precise microprocessor controls with adaptive control algorithms. The latest models, such as the MDF-DU703VH, set standards for performance with minimal power consumption.
PHC focuses not only on incremental improvements, but also on strategically controlled innovation - with measurable results over decades. Anyone who invests in a PHC model benefits from a manufacturer that combines technological excellence with a long-term perspective.
Commitment in Switzerland: Partnership with VITARIS
In Switzerland, VITARIS has been a sales partner for PHCbi laboratory devices, in particular ultra-low temperature freezers, since 2015. In addition to sales, training and commissioning, VITARIS also provides technical support and long-term maintenance.
Thanks to this close partnership, PHCbi can guarantee a high quality of support, short response times and excellent availability of spare parts on the Swiss market. The continuity of this collaboration strengthens the trust of laboratory customers in research, industry and clinics.
PHC stands for Japanese engineering, long-term reliability and strategic expansion in the healthcare sector. In combination with the support provided by VITARIS, PHCbi in Switzerland is today not only a technical but also a service-oriented premium provider in the field of ultra-low temperature technology.
Conclusion
Energy efficiency, maintenance safety, heat load and service quality are not trivialities - they are decisive in determining how reliably, economically and sustainably a laboratory appliance will function over many years. The differences are measurable - sometimes serious - and have a noticeable effect on operating costs, room comfort and the safety of sensitive samples.
Particularly in the field of ultra-low temperature technology, it is not only technical values that count, but also long-term experience, spare parts availability and service expertise. Established brands are clearly superior here: they not only offer sophisticated technology, but also established support structures, transparent standards and a robust service network - crucial for laboratories that cannot risk downtime.
Newcomers from Asia are visibly catching up in terms of energy efficiency and equipment. However, issues such as local support, spare parts supply and reliability over 10 to 15 years remain unresolved. As things stand today, long-term operational reliability can only be estimated to a limited extent. For this reason, anyone investing in critical infrastructure should think beyond the purchase price. More important are calculable operating costs, low failure risks, efficient maintainability and a manufacturer that will still be available in ten years' time. The cheapest solution is rarely the best - especially not in the long term.
As a long-standing partner of PHCbi in Switzerland, we are convinced that these products currently offer the most balanced combination of energy efficiency, reliability and serviceability. PHC focuses on genuine technological development and long-term availability - and this is noticeable in day-to-day operation.
And the economic effect? Even with a fleet of five appliances, the use of modern freezers can save between CHF 1,680 and CHF 3,508 a year in energy costs - depending on the initial situation, room temperature and operating behavior. In times of rising energy prices and increasing sustainability requirements, this is a clear competitive advantage.
ULT freezers are not short-term consumer goods - they are investments in safety and the future.
That's why we recommend: Seek individual advice. Together we will find the solution that suits your laboratory - technically sophisticated, economically viable and sustainable in the long term.
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