Memmert universal oven UN260, large-capacity heating and drying oven with natural convection, 256 litres, up to 300 °C

With an internal volume of 256 litres, the Memmert universal oven UN260 is clearly a floor-standing unit designed for businesses that regularly heat-treat, dry or temper larger batches. Like the smaller models in the series, it operates using purely natural convection within a temperature range of 20 to 300 °C, but now across up to 9 shelves. For materials testing and quality assurance in industry, where several test series run simultaneously and vibration-free operation remains crucial, the UN260 marks the entry point into the large-volume models of the UN series.

Natural convection on an industrial scale

Even with an internal volume of 256 litres, the Memmert UN260 universal oven does not require an air turbine or a recirculation motor. Heat rises purely by thermal convection, without a fan stirring up dust or light sample particles within the large interior. The working temperature range extends from at least 5 °C above room temperature up to 300 °C. With up to 9 shelves occupied simultaneously, uniform natural heat distribution is particularly advantageous for sensitive material samples or samples laid out in the open, for example in materials testing. A Pt100 temperature sensor of DIN Class A in a 4-wire configuration provides a setting accuracy of 0.1 °C up to 99.9 °C and 0.5 °C from 100 °C onwards, regardless of the unit size.

ControlCOCKPIT SingleDISPLAY for everyday industrial use

The UN260 is operated via the ControlCOCKPIT SingleDISPLAY, an adaptive, multifunctional digital PID microprocessor controller with a high-resolution TFT colour graphic display. The temperature can be set in Celsius or Fahrenheit, as well as the position of the exhaust air flap, programme duration, time zone and summer/winter time. A digital countdown timer with target time can be set from 1 minute to 99 days; the SetpointWait function only starts the process time once the setpoint temperature has been reached, ensuring reproducible results for industrial batches lasting several hours. The data logger can be read out and managed via the Ethernet interface; a time-limited trial version of the AtmoCONTROL software is available for download.

Capacity and dimensions of the Memmert universal oven UN260

The internal dimensions are 640 x 800 x 500 mm, whilst the external dimensions are 824 x 1183 x 684 mm. The scope of delivery includes two electropolished stainless steel grid shelves; the oven can accommodate up to nine shelves in total, more than any smaller UN model. The maximum load capacity is 300 kg for the entire unit and 20 kg per shelf. The interior consists of easy-to-clean stainless steel, reinforced by deep-drawn ribbing, with protected, integrated 4-sided all-round heating; the housing is made of textured stainless steel with a fully galvanised sheet steel rear panel. The UN260 is connected to 230 V (approx. 3,400 W) or 115 V (approx. 1,800 W), in both cases at 50/60 Hz, and remains single-phase despite the unit’s size.

Selection guide: an introduction to the large-volume models

The Memmert UN series with natural convection ranges from 32 to 749 litres internal volume. The UN260 is the first model in the range that is specifically designed as a floor-standing unit, rather than a benchtop unit.

If the 108-litre capacity of the Memmert universal oven UN110 is no longer sufficient, the UN260, with a capacity of 256 litres and a significantly larger footprint, is the next step up. For even larger industrial batches, the Memmert universal oven UN450 follows, with a capacity of 449 litres and a three-phase power connection. The full range can be found under Climate Chambers & Incubators.

Distinction: natural convection versus forced air circulation

With a capacity of 256 litres and 9 shelves, it is worth considering whether active air circulation might not be more appropriate anyway. Forced-air models in the UF series feature an electronically controlled air turbine and actively distribute heat throughout the interior, which ensures shorter heating times for very densely packed batches of varying sizes, though only from 10 °C rather than 5 °C above room temperature. For materials sensitive to dust or air movement, such as in materials testing with samples laid out in the open, the natural convection of the UN260 remains the more technically suitable choice. A forced-air model of a similar size is the Memmert UF450 universal oven with a capacity of 449 litres. Like all standard models in the series, the UN260 uses the ControlCOCKPIT SingleDISPLAY; the TwinDISPLAY with two screens is reserved for the ‘plus’ variants.

Safety according to DIN 12880 for large, valuable batches

Process reliability is crucial, particularly with a 256-litre load, which often runs for several hours or overnight. The UN260 features adjustable electronic temperature monitoring and a mechanical temperature limiter of protection class 1 according to DIN 12880, which switches off the heating when the temperature reaches approximately 20 °C above the maximum cabinet temperature. A self-diagnostic system assists with fault-finding, and 3 freely selectable temperature values can be calibrated. The unit bears CE and EAC markings as well as a UL test mark.

Installation, operation and disposal

For operation, a minimum clearance of 15 cm from the wall and a minimum clearance of 20 cm from the ceiling must be maintained; a minimum clearance of 5 cm is sufficient on the sides relative to the wall or an adjacent unit. With a net weight of around 110 kg and a footprint of 824 x 684 mm, the UN260 requires a permanently designated installation site with a load-bearing floor. It may be installed at altitudes of up to 2,000 m above sea level at an ambient temperature of 5 °C to 40 °C and a relative humidity of no more than 80 %, non-condensing. Electrically, the UN260 is designed for overvoltage category II and pollution degree 2; it must only be transported in an upright position. At the end of its service life, the UN260, as an electrical appliance, is subject to the German Electrical and Electronic Equipment Act (ElektroG) and must not be disposed of with household waste.

Typical applications

With an internal volume of 256 litres, up to 9 shelves and a load capacity of up to 300 kg, the Memmert universal oven UN260 is designed for applications with higher throughput and larger test batches.

• Heat treatment and drying of larger batches of material in industry
• Routine tempering, ageing and baking of material samples
• Material testing and quality assurance with high sample throughput
• Vibration-free operation with large numbers of dust-sensitive test specimens
• A complement to laboratories upgrading from the UN110 to significantly greater capacity

Investment rationale: Equipment designed for continuous industrial operation

The scope of delivery for the UN260 includes 2 electropolished stainless steel grid shelves as standard; the oven is designed to accommodate up to 9 shelves, each with a maximum load of 20 kg. Users who regularly utilise all levels should order additional grid shelves or perforated trays accordingly. For visual inspection without opening the door, a fully transparent glass door is available, along with interior lighting, an internal power socket and a levelling or mobile base frame. Those wishing to secure access can add a lockable door with a security lock. An AtmoCONTROL software licence is recommended for continuous data logging; for applications subject to standards, calibration and IQ/OQ/PQ services are available, including DAkkS calibration on request.

Frequently asked questions before purchase

Can the UN260 still be operated on single-phase power?
Yes, despite the unit’s size, the UN260 can be operated either on 230 V (approx. 3,400 W) or 115 V (approx. 1,800 W); a three-phase connection is only required from the UN450 upwards.

How many samples can be loaded at the same time?
Up to 9 shelves, each with a maximum load of 20 kg, giving a total load capacity of up to 300 kg.

How much floor space do I need to allow for?
A footprint of 824 x 684 mm, with a total height of 1,183 mm and a net weight of around 110 kg.

Is natural convection still sufficient with so many shelves?
Yes, for most heat treatment and drying processes. For very densely loaded batches with widely varying sample sizes, a forced-air model such as the UF450 can operate more uniformly.

What is the accuracy of the temperature control?
For the UN260, too, it is 0.1 °C up to 99.9 °C and 0.5 °C from 100 °C, measured via a DIN Class A Pt100 sensor using 4-wire technology, which is unchanged from the smaller models in the series.

Is the UN260 suitable for unattended continuous operation?
The mechanical temperature limiter, of protection class 1 according to DIN 12880 switches off the heating element in the event of an overtemperature of approximately 20 °C and is designed for long, unattended processes.

Technical details

Scope of delivery

• 1x Memmert universal oven UN260
• Factory calibration certificate (calibration at 160 °C)
• Fully insulated stainless steel doors with 2-point locking (compression door lock)
• 2x stainless steel grid shelf, electropolished

Regulatory information

The Memmert universal oven UN260 is registered with the Stiftung Elektro-Altgeräte Register (Stiftung EAR) under WEEE registration number DE 66812464.

Individual requirements and procurement service

Options available for the UN260 include fully glazed doors, interior lighting and a power socket, a levelling or castor-mounted base, a lockable door with a security lock, as well as reinforced grid shelves and perforated trays. A USB-to-Ethernet adapter and AtmoCONTROL software licences are available for data logging. In addition, we arrange calibration, IQ/OQ/PQ and maintenance services, including DAkkS calibration on request. Do you require any of these accessories or assistance in selecting the right universal oven for your application? Through our procurement service, we are happy to assist you with procurement and configuration.