Most rotary evaporators do the same job: turn a flask in a warm bath under reduced pressure and condense what comes off. The differences that matter to a buyer are in the frame around that job. This guide answers how to choose a rotary evaporator in the order the decisions usually fall: flask size, lift, condenser geometry, bath and control, then the vacuum and cooling that complete the system. Product specifications in Tables A and B are summarized from ACS Material product specifications; each model name links to its product. Section 7 lists its sources; the notes on missing data and the compatibility cautions are our own guidance.
Quick answer: Start with composition, intended charge, required removal rate and sample limits. Choose a nominal flask size, then confirm its permissible working fill; a half-full teaching guideline is not a model-specific charge rating. The benchtop models take flasks up to 3000 mL, while the pilot models take 5, 10, 20 or 50 L. Compare lift actions, condenser configuration, bath and vacuum control. Distinguish an explicitly specified pairing from an optional component or related product, and confirm the complete pump, controller and cooling configuration before ordering.
1. Start with the Process, Not the Catalog
Four process facts to document
A rotary evaporator buying guide should start with the work. The complete guide to rotary evaporation organizes selection around solvent, batch volume, required throughput and sample thermal sensitivity. Use those as a starting checklist, not a complete specification or compatibility assessment.
Record composition, intended charge, removal-rate target and sample limits before comparing models [1][2]. Pure-solvent pressure-temperature relationships in the solvent boiling points article are starting estimates, not validated bath settings or mixture methods. Working fill, heat transfer, condensation, gas load and the installed configuration need separate assessment; Δ20 is illustrative.
What this guide compares
The ALab™ range includes five evaporator lines: the benchtop RE100-S, RE100-Pro and RE100-CV, the 20 L RE200-Pro, and the RE-E series with 5, 10, 20 and 50 L flasks. Specified pairings, optional components and related products are distinguished below. No model is ranked. The tables compare documented features; specifications alone do not validate a complete configuration for your process.
2. Flask Size: Nominal Capacity and Working Charge
The half-full teaching guideline
University of York teaching guidance advises keeping the flask less than half-full and warns that greater filling increases bumping risk [17]. This is teaching guidance, not a specified working-charge rating for the models below. Confirm fill limits, sample behavior, headspace and the operating procedure for the selected configuration. Do not convert a 3, 20 or 50 L nominal flask directly into an approved 1.5, 10 or 25 L charge.
Rotovap 2L vs 5L: flask, charge or bath?
A 2 L flask and a 2 L liquid charge are different requirements. The RE100-S and RE100-Pro have a specified 50–3000 mL flask range, and the RE100-CV accommodates flasks up to 3000 mL; those statements do not approve a 2 L charge. The RE500-E lists a 5 L evaporating flask. By contrast, the RE100-S and RE100-Pro's 5 L figure describes the heating bath, not the evaporating flask. For "rotovap 2L vs 5L", first establish which volume is being specified.
Benchtop or pilot
Compare the specified flask ranges with a confirmed working fill, not with nominal capacity alone. The RE200-Pro is a 20 L pilot-scale system whose parameters need re-optimization for vapor load and condenser duty. Under geometrical similarity, total area per nominal volume falls as size increases [3], but actual heated area, film behavior and permissible charge depend on the configuration. Flask size alone does not approve a method or establish throughput.
3. The Five Lines Side by Side
Flask, bath, lift and speed
| Line | Evaporating flask | Bath | Lift | Speed range |
|---|---|---|---|---|
| RE100-S | 50–3000 mL | 5 L water/oil bath, RT–180 °C; independent temperature control | Manual 110 mm + auxiliary 100 mm | 20–200 rpm |
| RE100-Pro | 50–3000 mL | 5 L water/oil bath, RT–180 °C | Motorized, 150 mm; auto lift-out on power failure | 20–280 rpm |
| RE100-CV | Up to 3000 mL | Heating RT to 180 °C | Automatic 150 mm; flask moves to a safe position after power loss or when the timer ends | 20–280 rpm |
| RE200-Pro | 20 L; 10 L receiving flask with drain valve | Water/oil bath Ø 450 × 240 mm, RT–180 °C | Motorized, 180 mm, one-click; lifting-overload protection | 10–150 rpm |
| RE-E series | 5 / 10 / 20 / 50 L | Water bath 20–100 °C (standard); oil bath 20–180 °C (optional) | Motorized lifting of the heat bath; 130 / 200 / 180 / 253 mm | 20–180 rpm (5 L); 20–130 rpm (10–50 L) |
Condenser, capacity, vacuum and control
| Line | Condenser | Max. evaporation capacity (test liquid) | Vacuum features | Display / supply |
|---|---|---|---|---|
| RE100-S | Vertical, 1200 cm² (1700 cm² available for selection) | 1.56 L/h (H2O) | Matched C410 pump specified with the quotation; programmable vacuum controller can be added | LED; 100–120 / 200–240 V |
| RE100-Pro | Vertical, 1700 cm² | 1.56 L/h (H2O) | C410 pump specified with the quotation; programmable vacuum controller can be added | LCD; 100–120 / 200–240 V |
| RE100-CV | Self-cooling metal condenser; RT to −40 °C; separately listed cooling power 725 W (test temperature not specified); area not specified | — | Built-in vacuum pump controller; 1–1000 mbar; single-point or programmed control, 5 programs × 5 steps | LCD touchscreen; 100–120 / 200–240 V |
| RE200-Pro | Two-section vertical triple-coil, 1.2 m² | 4.5 L/h (75% alcohol) | Ultimate vacuum less than 2.6 mbar; pump and vacuum control selected separately at quotation | LCD; 220 V |
| RE-E series | Double-layer, anti-backflow; vertical main condenser 0.28 / 0.49 / 1.29 / 1.75 m² | 2 / 3.8 / 5 / 11 L/h (75% alcohol) | Ultimate vacuum 9 mbar; vacuum controller optional | LCD, PID; 220 V |
Reading the tables fairly
Source: ACS Material product specifications (October 2026); the line names in the first table link to each product. A dash means the specification is not listed. It does not mean the feature is absent. Capacity figures use different test liquids and are not a common-process ranking. The pilot models are rated with 75% alcohol; the alcohol, concentration basis and complete test conditions are not specified. Solvent properties and their reference temperatures matter [4][5]; no rate conversion is made here. Vacuum ratings are not operating pressures [6][7]. RE-E lists equal-area main and secondary condensers for 10/20/50 L, but only a main condenser for 5 L. Only main areas are shown; supplied configuration requires confirmation.
4. Lift: Manual, Motorized or Bath-Lift
Why the lift matters
Check how the design separates the flask from the bath during shutdown and what response, if any, is documented for power loss. The guide to how a rotary evaporator works discusses lifting clear before releasing vacuum. Follow the selected model's operating instructions; motorized motion, automatic failure response and safe handling of detached glassware are separate questions.
Three approaches
- Manual with auxiliary lift. The RE100-S combines a manual 110 mm lift with a 100 mm auxiliary lift and an adjustable immersion angle. ACS Material suggests the RE100-S when manual positioning is preferred.
- Motorized flask lift. On the RE100-Pro, the 150 mm motorized lift raises the evaporating flask out of the bath automatically when power is interrupted. The RE100-CV has an automatic 150 mm stroke, and its flask automatically moves to a safe position after power loss or when the timer ends. The RE200-Pro has one-click motorized lifting over 180 mm, with lifting-overload protection among its safety features.
- Motorized bath lift. The RE-E series moves the bath rather than the flask, using stepless automatic motor lifting of the heat bath, with strokes of 130 to 253 mm depending on size.
Do you need a motorized lift?
When evaluating a motorized lift rotovap, distinguish routine positioning from a specified power-loss response. The RE100-Pro and RE100-CV have such responses; none is specified for the RE200-Pro and RE-E. A motorized lift is not permission for unattended operation or proof of safe manual handling. Review loss of power, cooling and ventilation as well as hot baths and evacuated glassware [12][13][18].
5. Condenser Geometry: Vertical vs Diagonal, Coil Area and Self-Cooling
Vertical vs diagonal condenser
No diagonal-condenser option is listed for these configurations. This guide therefore does not assign an unlisted diagonal option a footprint or performance advantage. Compare installed height, depth, hose routing and glassware-removal clearance for the configuration actually offered.
Across the five lines, every listed glass condenser is vertical: 1200 or 1700 cm² on the benchtop units, a two-section vertical triple-coil on the RE200-Pro, and vertical main condensers for all four RE-E sizes, with secondary condensers listed for 10, 20 and 50 L. For the RE200-Pro, ACS Material advises allowing clearance above the condenser column for glassware handling.
Area and coolant temperature
The RE100-S ships with a 1200 cm² vertical condenser for routine solvent removal, and offers 1700 cm² for applications that benefit from additional condensing surface or greater vapor-load capacity. As our complete guide notes, benchtop vertical coil condensers commonly offer 1200–1700 cm², while pilot-scale two-section coil assemblies reach the order of a square meter. The RE200-Pro has 1.2 m² and the RE-E main condensers 0.28 to 1.75 m². Heat removal also depends on the overall heat-transfer coefficient, effective area, coolant flow, vapor conditions and the appropriate mean temperature difference [9][10]. The Δ20 °C arrangement is an illustration, not a cooling-capacity guarantee.
Self-cooling: no separate chiller
The RE100-CV takes a different route. It introduces refrigerant directly into a metal condenser, with a condenser range of RT to −40 °C, in a compact design that needs no separate chiller. Its 725 W cooling figure is given without a test temperature; it does not establish 725 W at −40 °C or equivalence to 700 W at 20 °C. Confirm cooling performance for the intended temperature and load; condenser area is not specified.
6. Bath and Control
Bath range and medium
Across these models, heating ranges reach 180 °C; RE-E requires the optional oil-bath configuration for that upper range. The benchtop RE100-S and RE100-Pro use a 5 L bath that switches between water and oil, with control accuracy of ±1 °C in water and ±3 °C in oil. The RE100-S bath has independent temperature control, so it can also be used on its own as a standard laboratory heating bath. The RE-E series heats with water from 20 to 100 °C as standard and offers an oil bath from 20 to 180 °C as an option. On the RE200-Pro, a suitable heat-transfer oil is required for higher temperatures. Choose medium and operating limits from the approved method and instrument instructions, not solvent boiling-point labels alone. The equipment range is not a sample-safety limit; oil requires appropriate handling and fire precautions [12][14].
Display, timers and programs
Control ranges from simple readouts to stored programs. The RE100-S uses LED readouts with interval rotation of 1–999 s for drying; the RE100-Pro, RE200-Pro and RE-E series use LCDs with timers; the RE-E adds a steam temperature sensor that reports vapor temperature in real time. The RE100-CV has a built-in vacuum pump controller: a touchscreen sets 1–1000 mbar in single-point or programmed mode and stores up to 5 programs of 5 steps each. The RE100-S and RE100-Pro offer an optional programmable controller for pressure ramps that help reduce bumping. General control principles [11] do not establish the unnamed controller's model, transition profile or a guaranteed outcome.
7. Vacuum and Cooling: Specified Pairings and Related Products
Specified pairings at a glance
| Evaporator | Vacuum | Cooling |
|---|---|---|
| RE100-S, RE100-Pro | Matched C410 chemistry diaphragm pump (13 mbar · 25 L/min), specified with the quotation; a programmable vacuum controller can be added | CCP5-Mini: positioned for the 3 L class; final suitability requires confirmation. DCP-5: confirm for the intended process |
| RE100-CV | Built-in vacuum pump controller; C2000T, C960T and VC100 offered as related products; compatibility not confirmed | Self-cooling condenser; no separate chiller needed |
| RE200-Pro | Pump and vacuum control selected separately and confirmed at quotation; the C410 is specified for the RE100-Pro and RE100-S, not for this system | Cooling sized against the process at quotation |
| RE-E series | Vacuum controller optional; VC100, C2000T and C960T offered as related products; compatibility not confirmed | Chiller pairing: not specified |
The pumps and controller in one line each
- C410 diaphragm pump: oil-free, 13 mbar ultimate vacuum, 25 L/min free air; the matched vacuum source for the RE100-Pro and RE100-S.
- C960T diaphragm pump: triple stage, 3.6 m³/h (60 l/min) at atmospheric pressure, rated ultimate vacuum <2 mbar abs.
- C2000T diaphragm pump: triple stage, 10.8 m³/h (180 l/min) at atmospheric pressure, rated ultimate vacuum <2 mbar abs.
- VC100 vacuum controller: 1–1000 mbar setting and measurement range, single-point or programmed control, up to 5 programs of 5 steps; together with a vacuum pump, it generally forms the vacuum control system of a rotary evaporator.
Ultimate vacuum is a blank-off rating, not a guaranteed working pressure [6][7]. Gas load and effective pumping speed affect pressure during a run [8]; no speed curve or pump-down prediction is inferred here. Being offered as related products does not establish compatibility. VC100 lists pump-power limits of 400 W at 50 Hz and 500 W at 60 Hz; C2000T lists 750 W, exceeding both. Do not assume an approved control connection. Confirm the electrical and control configuration; do not assign VC100's limits to the RE100-CV's built-in controller.
The chillers
The CCP5-Mini and DCP-5 recirculating chillers are both rated at 700 W of cooling at a 20 °C coolant temperature from a 4.5 L tank. The CCP5-Mini runs from −20 °C to room temperature on 220 V / 50 Hz, and is positioned for cooling rotary evaporators of the 3 L class. The DCP-5 covers −20 to 40 °C on 100–120 V / 200–240 V. The 700 W figure is a reference at 20 °C, not a universal duty allowance or capacity at another setpoint. Confirm usable capacity, delivered flow, fluid compatibility and test conditions for the intended process. No capacity curve at other temperatures or complete system-suitability assessment is specified.
8. A Decision Path in Six Questions
Compare features against the specifications
| Question | Feature sought | Specified features to compare | Check before quotation |
|---|---|---|---|
| Required nominal flask size? | Up to 3000 mL | RE100-S and RE100-Pro: 50–3000 mL; RE100-CV: up to 3000 mL | Permissible working fill and configuration, separately |
| 5, 10, 20 or 50 L | RE-E series: 5/10/20/50 L; RE200-Pro: 20 L only | Nominal size is not an approved charge | |
| How should the flask leave the bath? | Manual positioning | RE100-S | Lift stroke |
| Motorized flask positioning | RE100-Pro, RE100-CV and RE200-Pro | Stroke and operating instructions | |
| Listed automatic response to power loss | RE100-Pro: flask lifts out; RE100-CV: moves to its specified safe position | Trigger and action; no equivalent response specified for RE200-Pro | |
| Bath moves instead of flask | RE-E series | Lifting mode | |
| Preferred condenser arrangement? | Listed self-cooling configuration | RE100-CV | Required load and temperature; test conditions |
| External-coolant glass condenser | RE100-S, RE100-Pro, RE200-Pro and RE-E | Condenser configuration, coolant flow and cooling capacity | |
| How will vacuum be controlled? | Built in | RE100-CV | Vacuum setting range |
| Separate controller | RE100-S, RE100-Pro (can be added); RE-E (optional) | Optional-controller details and compatibility. | |
| Feed or collect during the run? | Continuous feeding | RE-E series | Continuous feeding |
| Distillate drawn off under vacuum | RE200-Pro (drain and switch valve); RE-E (automatic switching valve) | Receiving flask, valves | |
| What supply is available? | 100–120 V or 200–240 V | RE100-S, RE100-Pro, RE100-CV | Voltage / frequency |
| 220 V | RE200-Pro, RE-E series | Voltage; RE200-Pro electrical connection at quotation |
Before you request a quotation
Have the Section 1 process description ready, together with available space, service clearances and mains supply. For RE200-Pro, ACS Material calls for selection against solvents, batch size and target working pressure, including the electrical connection. Request an itemized configuration identifying included and optional equipment, glassware, working-fill limits, controls and utilities. This description also informs, but does not replace, the chemical hygiene and ventilation review [12][15][16].
9. Frequently Asked Questions
How do I choose a rotary evaporator?
Start from composition, intended charge, required rate and sample limits. Compare nominal flask sizes, then confirm permissible working fill. Check the documented lift action, condenser, bath and controls, and distinguish specified pairings from related products. Final selection requires confirmation of the complete configuration.
Should I buy a 2 L or a 5 L rotovap?
The RE100 lines accommodate nominal flask sizes up to 3000 mL; the RE500-E lists a 5 L evaporating flask. The RE100-S and RE100-Pro's 5 L specification is the bath volume. These nominal sizes do not establish allowable liquid charges.
Vertical or diagonal condenser: which should I pick?
No diagonal option is listed for the five evaporator lines. The glass-condenser listings are vertical; RE100-CV uses a self-cooling metal condenser. Check the confirmed layout, headroom, depth, hoses and service clearance rather than assuming an unlisted alternative is available.
What should I check in a motorized lift?
Compare the action needed: manual positioning, motorized flask movement or motorized bath movement. RE100-Pro and RE100-CV have specified automatic power-loss responses; RE200-Pro and RE-E have motorized motion, but no such response is specified. These features do not by themselves approve unattended operation.
Which pump and chiller go with each evaporator?
RE100-S and RE100-Pro are described as pairing with the C410; their optional programmable controller is not named. RE200-Pro pump, chiller and control options are confirmed at quotation. RE-E and RE100-CV related-product links do not establish approved combinations. RE100-CV's built-in controller does not establish that a vacuum pump is included. Confirm the complete configuration and operating conditions.
10. Keep Exploring Rotary Evaporation
- Rotary Evaporation: The Complete Guide: principles, setup, condensing and scale-up
- How a Rotary Evaporator Works: Five Steps
- Rotary Evaporation vs Simple Distillation
- Solvent Boiling Points Under Vacuum: the Δ20 °C illustration and pressure–temperature tables
- Why the Flask Rotates: Films, Area and Bumping
Browse all ALab™ rotary evaporators and accessories