Male hand turns a cube to change "2 degrees Celsius" to "1.5 degrees Celsius."
Depending on the age of a refrigerated bath, it may use a refrigerant that is either non-serviceable or no longer legal.

Balancing Performance and Sustainability in Clinical Labs

Tips for purchasing refrigerants that are less harmful to the environment

Scott Pratt

Scott Pratt, application specialist, temperature control, Thermo Fisher Scientific.

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Published:Oct 26, 2022
|3 min read
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Scott Pratt, application specialist, temperature control, Thermo Fisher Scientific.

Reducing energy consumption and waste in clinical laboratories has become an increasingly high priority. Today, amid growing pressure to operate more sustainably, lab managers and researchers are paying more attention to the lifecycles of the products they use, as well as the related energy requirements, to identify opportunities for more sustainable practices.

Undertaking this new environmental effort should include a closer look at how common lab equipment, including water baths, heated bath circulators, and refrigerated bath circulators, are selected and operated. These pieces of equipment are present in almost every clinical lab, and come with a wide variety of options, ensuring performance is never compromised.

What to look for when purchasing lab equipment

Ecofriendly purchasers of water baths would be wise to look for water baths that have timers to automatically shut off the equipment at night or when it’s inactive for a certain period of time. Additionally, keeping the lid on whenever possible can limit how often the heater cycles, reducing energy use. If that is not possible, users can consider using floating insulating balls to fill the spaces between vessels or having a custom cover made with an opening that accommodates the vessels.

Heated bath circulators offer similar options. However, it’s worth noting that these pieces of equipment also include a pump that consumes additional energy, so when possible, opting for a simple water bath helps save energy.

The same recommendations and best practices apply to refrigerated bath circulators, but refrigerated baths provide the most significant opportunity for improved sustainability.

Depending on the age of a refrigerated bath, it may use a refrigerant that is either non-serviceable or no longer legal for use in new products due to new requirements for low Global Warming Potential (GWP) refrigerants.

The global warming impact of different gases

GWP was developed to compare the global warming impacts of different gases to carbon dioxide, which, as the reference gas, has a GWP value of 1.0. Specifically, it is a measure of how much energy the emissions of 1.0 ton of a gas will absorb over a given period relative to the emissions of 1.0 ton of carbon dioxide.

The European F-Gas Regulation was updated in 2016 to include a ban on any F-Gas with a GWP of greater than 2,500 starting in January 2020. Notably, many refrigerated bath circulators with temperature ranges of -0°C or lower used the R404a refrigerant with a GWP of 3,920, meaning that those products could no longer be sold in Europe or Canada (per the Montreal Protocol), while alternatives are recommended in the US (SNAP).

Replacement refrigerants

Refrigerants that are compliant across geographies and capable of achieving temperatures of -30°C or lower are limited. Examples of these replacement refrigerants include R452A (GWP: 1,945), R449A (GWP: 1,397), and R290A (GWP: 3). While all three meet the various compliance standards, R452A and R449A have a potential for global warming that is hundreds of times higher than the R290.

R290 is not new, is naturally occurring and offers excellent cooling performance and low environmental impact, but as a flammable hydrocarbon (propane), its use was previously limited to no more than 150 g, making it insufficient to replace other refrigerants for higher cooling capacities and lower temperatures.

Fortunately, Underwriters Laboratory (UL) recently raised the limit to 500 g (UL 60335-2-89), which is enough to rule in R290 as a viable option for refrigerated circulating baths. While not a “drop in” replacement because it requires other hardware changes to meet the stringent UL safety requirements, some new refrigerated bath circulators are now available with R290.

Making progress toward environmental goals

Depending on how many of these products a clinical lab has, these simple modifications will not only lower power use but also decrease the load on the HVAC system. Refrigerated products that use refrigerants less harmful to the environment will also be serviceable further into the future as the industry continues to prioritize sustainability.

These simple steps, among others, can help clinical labs achieve desired performance while making progress toward environmental goals.