Hi Reader, have you been searching for a more sustainable piece of equipment lately?
When it comes to evaluating which claims are valid, I’ve personally seen very few advertised enhancements that weren’t.
However, the main question remains: does a particular benefit make the entire instrument sustainable?
This can be hard to judge, so let’s explore it using a concrete example:
Today's Lesson: How to Assess Instruments
An example on how to evaluate sustainability claims
Number Of The Day
The manufacturing of an average fridge releases approximately 300 kg of CO2e depending on the exact circumstances. Unfortunately, this is the only laboratory instrument for which Life Cycle Analysis (LCA) data is available. Similarly, the only item with a relatively detailed and freely available LCA is the Eppendorf Biobased Tubes. For everything else, we must become active.
300
Are Bead Baths More Sustainable?
A bead bath is similar to a water bath, except it is filled with solid metal or glass beads. Generally, any water bath without moving parts can be converted into such a bead bath.
Many companies that sell these instruments claim the one or other environmental benefit. But are they truly more sustainable?
To determine whether an instrument is more sustainable than its alternative, we need to consider a number of aspects.
1. Performance
Although beads can be heated to higher temperatures than water (up to 180°C) and cooled below -80°C, there is performance drawback: they transfer heat more slowly.
The contact surface for heat transfer in water is as big as the immersion depth of the tube. With beads, the air spaces lead to inconsistent heat transfer. In the graphic, the relatively slmall contact points between tube and beads are indicated in red.
For applications involving large (500 mL) or frozen vessels, incubation in beads may take 2–3 times longer. On top, for applications such as heat shock during bacterial transformations—where samples are typically heated to 42°C in under a minute—achieving the same result with beads requires incubating the sample at 50–55°C for one minute.
2. Running Efficiency
Because beads do not condense, and are made of solid material, they retain heat better.
Comparing the energy required to maintain different temperatures in a 12L bath for 24 hours, at 20°C room temperature:
3. Type and Volume of Required Materials
These baths require either water or beads to run. Beads can be made of various materials. The most common models seem to be made of aluminum.
To compare the greenhouse gas impact, let us assume the beads last two years (as it is guaranteed by manufacturers) and we use a volume of 4L:
While you do not need to worry about the transport of the raw materials according to this analysis, we cannot properly account for the footprint of the delivery to you. If we assume a transport by truck for a few hundred kilometers, we could approximate a footprint of a few hundred grams of CO2e.
| Aluminum: 18.4–40.8 kg CO₂e
| Stainless Steel: 39–54.6 kg CO₂e
| Glass: 2.5–8 kg CO₂e
| Water: 0.00552–0.127 kg CO₂e (12 exchanges in 2 years)
| Energy: 72 kg CO₂e (200 days à 15h/day) | 210 kg CO₂e (24/7)
For anyone interested, the carbon intensity for water is 0.00552–0.127kg CO2e per liter. Also, I used a density of 2.7 kg/L for aluminum, 7.8 kg/L for steel and 2.2–3.2 kg/L for glass for these calculations.
Meaning that the lower energy consumption makes up for the embodied carbon in the bead material.
4. Waste Generation
Wastewater impact is already accounted for in section 3.
Bead baths allegedly require less maintenance, but I was not able to verify or quantify this claim.
5. Embodied Carbon
No full Life Cycle Assessment (LCA) is available for bead baths. As a very, very rough estimate, we can assume their footprint between that of a microwave and a fridge, hence ranging between 84–300 kg CO₂e per unit.
Since a water bath and a bead bath require a similar base instrument, neither has an advantage.
6. Handling
Bead baths offer several advantages:
No need for frequent water exchanges.
No floats or bottleneck weights required.
No dripping after sample removal.
Can accommodate items such as plates easily.
However, there are drawbacks:
Beads near the heating element can become extremely hot, requiring mixing with a rod before reaching equilibrium.
Heating beads up takes longer.
7. Risk Considerations
Bead baths are less prone to contamination. Manufacturers still recommend spraying them with ethanol every 2–4 weeks. Given that contaminations can disrupt entire experimental series, this is an important psychological and environmental factor.
When evaluating the sustainability of laboratory equipment, several critical factors should be taken into account. Although it should be included by technical standards, I did not add price because already is well understood as the main decision driver.
On the downside, bead baths are marketed to be kept "always on". While this may be convenient, it undoes most of the energy-saving benefits.
Applying The Knowledge
Is a Bead Bath Financially Affordable? Based on our previous assumptions of 4L per bath, extrapolated to one year:
| Cost of Beads: $450 (Aluminum) | $300 (glass)
| Cost of Water: $0.024–$0.24 ($0.001–$0.01 per liter)
| Energy Costs Saved: $14.40–$28.80 (15h/200 days) / $42–$84 (24/7)
To financially amortize the beads, it would take 3.5 to 32 years. Given the price of the beads, the decision will mainly depend on how many water baths should be converted.
So, Is a Bead Bath More Sustainable?
While switching to a bead bath offers some sustainability improvements, the difference is not dramatic.
If we compare this to an example where 2.5 million liters of liquid nitrogen (at 0.07 kg CO₂e per liter) are saved due to a modern MS instrument, the impact would be 175,000 kg of CO₂e saved.
Upcoming Lesson:
Driving Change Like A Pro - An Example From Belgium
How We Feel Today
References
Gasia, J., 2021. Life cycle assessment and life cycle costing of an innovative component for refrigeration units. J. Clean. Prod., 295, 126442. doi:10.1016/j.jclepro.2021.126442
Cascini, A., 2015. Comparative carbon footprint assessment of commercial walk-in refrigeration systems under different use configurations. J. Clean. Prod., 112(5), 3998-4011. doi:10.1016/j.jclepro.2015.08.075
Garcia Paz, F.A., 2024. Recovery of materials from refrigerators: A study focused on product distribution, recyclability, and LCA evaluation. Sustainability, 16, 1082. doi:10.3390/su16031082
Al-Doori, S., 2025. A comparative life cycle assessment (LCA) of monopole antenna and microwave oven for water heating. Comput. Eng. Phys. Model., 8, 1344. doi:10.22115/cepm.2024.488924.1344
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