Caltherm designs and manufactures bespoke vacuum ovens for industries that need precise, low-temperature drying, curing and degassing of heat-sensitive materials. With over 40 years of thermal engineering experience, we build vacuum drying ovens trusted by aerospace, pharmaceutical and research organisations across the UK and worldwide.
Ready to design your vacuum oven? Get in touch with our engineering experts today.
How Does a Vacuum Oven Work?
A vacuum oven works by heating materials inside a sealed chamber while reducing the air pressure with a vacuum pump. By lowering the pressure, the boiling point of moisture and solvents drops significantly, allowing them to evaporate at much lower temperatures than in a conventional oven.
This process:
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Prevents oxidation by eliminating oxygen inside the chamber.
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Protects heat-sensitive materials by reducing thermal stress.
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Speeds up drying compared to atmospheric ovens.
Vacuum ovens are particularly effective for drying, curing, or degassing delicate materials where precision and product integrity are essential.
Why Lower Pressure Allows Lower Drying Temperatures
The boiling point of a liquid depends on the pressure around it. At normal atmospheric pressure, water boils at 100°C. Under a strong vacuum, that falls to around 30°C or lower. Solvents behave in the same way.
This is what makes vacuum drying so effective for delicate products. Moisture and solvents can be driven off quickly at temperatures that would barely register in a conventional oven, so the product never has to face the thermal stress that causes damage, distortion or degradation.
Removing the air also removes the oxygen. Without oxygen in the chamber, materials cannot oxidise or discolour during processing. This matters for electronics, reactive metals, powders and pharmaceutical products.
How Heat Reaches the Load
In a conventional oven, circulating air carries heat to the product. A vacuum oven has almost no air to circulate, so heat is transferred mainly through conduction from heated shelves and through radiation.
For this reason, shelf design, load contact and product arrangement are central to every Caltherm vacuum oven. We engineer each system around your load so that heat is delivered evenly and predictably, cycle after cycle.
What is a Vacuum Oven Used for?
A vacuum oven is used for drying, curing, degassing, and heat treatment processes that require low-pressure environments. These ovens prevent oxidation and thermal degradation, making them ideal for:
- Drying heat-sensitive materials. Removing moisture and solvents at low temperatures without thermal damage.
- Degassing. Removing trapped air from resins, silicones, potting compounds and castings before they set, preventing voids and weak points.
- Drying hygroscopic materials. Removing absorbed moisture from plastics and powders before moulding or further processing.
- Electronics and battery components. Drying PCBs, lithium battery components and assemblies that would be damaged at conventional drying temperatures.
- Outgassing. Preparing components for high-purity and aerospace environments, where trapped volatiles could cause contamination later.
- Materials testing and research. Controlled, repeatable low-pressure conditions for laboratory and R&D work.
Commonly used in pharmaceutical manufacturing, aerospace, electronics, and materials science, vacuum ovens offer precise temperature control and consistent, contamination-free results.
Vacuum Oven Features and Upgrades
- Powered door(s) and load/unload systems
- Programmable temperature controllers
- Digital data logging
- Load temperature monitoring
- UKAS traceable calibrated thermocouples
- Customisable work handling solutions
- Vacuum pumps and receivers
- Stainless steel options
Tailor your vacuum oven with a wide range of high-performance options:
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Temperature range up to 120°C
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Fully integrated vacuum system with pumps and receivers
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Inflatable door seals for enhanced vacuum integrity
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Electrically heated with solid state relay (SSR) control
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Custom loading/unloading mechanisms
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UKAS-traceable thermocouples and load monitoring
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Stainless steel internal chambers available
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Digital data logging and programmable controllers
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Multiple safety features included as standard
Vacuum Oven Applications
Our vacuum ovens are suitable for:
- Materials testing and research
- Aerospace component production
- Pharmaceutical processing
- Food industry applications
Why Caltherm Vacuum Ovens?
- Tailored engineering: Every oven is designed to your exact specifications.
- Safety and compliance: Every oven is CE and UKCA marked and built in Britain, with ATEX-rated options available for processes involving flammable solvents.
- Proven experience: Over 40 years in vacuum heat technology.
- Full lifecycle support: From design to after-sales service and maintenance.
Vacuum Heat Treatment Systems
Caltherm also designs advanced vacuum heat treatment systems for applications requiring precise thermal processing in controlled environments. These systems are ideal for annealing, brazing, and sintering, especially in the aerospace and materials sectors.
Custom-Built Vacuum Ovens for Your Application
Tailored for aerospace, pharmaceutical, and advanced manufacturing, our vacuum systems deliver controlled, contamination-free processing for heat-sensitive applications.
Vacuum Ovens – Frequently Asked Questions
What is a vacuum oven used for?
A vacuum oven is used for drying, curing, degassing, and heat treating materials in a low-pressure environment. It’s especially useful for applications that require gentle, oxidation-free drying of heat-sensitive products such as pharmaceuticals, electronics, and aerospace components.
What are the benefits of vacuum drying over traditional drying methods?
Vacuum drying offers several key advantages:
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Faster drying times
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Lower drying temperatures
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Reduced oxidation and contamination risk
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Gentle handling of delicate or volatile materials
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Improved product quality and consistency
Do your vacuum ovens meet safety and compliance standards?
Absolutely. All Caltherm vacuum ovens are designed and built in compliance with international safety standards and include multiple built-in safety features. We also offer UKAS-traceable calibration as standard.
Do you offer installation and commissioning services?
Yes. Our team handles the full lifecycle: design, manufacture, delivery, installation, commissioning, and after-sales support—ensuring a smooth experience from concept to production.
How do I request a quote or consultation?
You can get in touch with us directly through our contact form, or call us to speak with one of our vacuum oven specialists. We’ll be happy to discuss your requirements and provide a tailored solution.
What industries use vacuum ovens?
Vacuum ovens are widely used in industries where precision and low-temperature drying are critical. Common applications include pharmaceuticals (for solvent removal and heat-sensitive drugs), aerospace (for composite curing and component processing), electronics (for degassing and moisture removal), materials science and R&D (for controlled testing), and the food industry (for gentle drying without damaging product quality).
Their ability to prevent oxidation and maintain product integrity makes them essential across advanced manufacturing sectors.
How are vacuum ovens different from vacuum furnaces?
While both operate under reduced pressure, vacuum ovens are designed primarily for low-temperature drying, curing, and heat treatment of sensitive materials. They excel in applications that require gentle processing and protection against oxidation. Vacuum furnaces, on the other hand, are built for high-temperature thermal processing such as brazing, sintering, annealing, and heat treatment of metals and alloys.
In short, ovens are used for delicate, lower-temperature processes, while furnaces handle heavy-duty, high-temperature applications.
Can you dry solvents in a vacuum oven?
Yes. Vacuum ovens are commonly used to safely remove solvents from samples and products. By lowering the boiling point, solvents evaporate more quickly and at lower temperatures, protecting sensitive materials from heat damage.
What temperature range can vacuum ovens achieve?
Most vacuum ovens are designed to operate up to 120°C, though Caltherm can engineer bespoke systems to meet specific temperature requirements. This flexibility makes them ideal for processes requiring controlled, low-temperature environments.
Is a vacuum oven safe for pharmaceutical applications?
Absolutely. Vacuum ovens are widely used in pharmaceutical manufacturing because they ensure contamination-free drying, precise temperature control, and compliance with strict safety standards. Caltherm designs ovens with features such as UKAS-traceable thermocouples and programmable controllers to meet these critical demands.
Can a vacuum oven be used for curing?
Yes, for certain resins and adhesives, particularly where trapped air must be removed. For powder coating, paint and most standard adhesive curing, a conventional curing oven is faster, larger and more cost-effective.
Caltherm (UK) Ltd
Caltherm is Britain’s leading Industrial Oven, Dryer and Furnace manufacturer.
Rowhurst Ind Est, Chesterton, Newcastle, Staffordshire, ST5 6BD
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