Memmert UN450 Universal Oven, large-capacity heating and drying oven with natural convection, 449 litres, up to 300 °C

The Memmert UN450 universal cabinet offers an internal volume of 449 litres within a comparatively modest overall height of 1,247 mm, meaning it fits even under lower ceilings where a taller model would not. Like all natural convection models in the series, it operates without a fan in the temperature range from 20 to 300 °C and is powered by three-phase current due to the heating power required. For industrial and research facilities wishing to heat-treat large batches without vibration, without needing a particularly tall unit, the UN450 is the ideal solution.

Natural convection with a large internal volume

Even with an internal volume of 449 litres, the Memmert UN450 universal chamber does not require an air turbine or a forced-air fan. Heat rises purely by convection, without a fan stirring up dust or light sample particles within the large interior. The operating temperature range extends from at least 5 °C above room temperature up to 300 °C. Natural convection remains in high demand even in this size category, particularly for industrial material samples that must not be affected by air movement. 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.

ControlCOCKPIT SingleDISPLAY and three-phase connection

The UN450 is controlled via the ControlCOCKPIT SingleDISPLAY, an adaptive, multifunctional digital PID microprocessor controller with a TFT colour graphic display, which can be used to set the temperature, exhaust air damper position, programme duration and time zone. A digital countdown timer ranging from 1 minute to 99 days and the SetpointWait function – which only starts the process time once the setpoint temperature has been reached – ensure reproducible processes, even during long, unattended runs. As a chamber of this size requires correspondingly higher heating capacity, the UN450 is powered by 400 V three-phase current and 3 x 230 V without a neutral conductor at 50/60 Hz and with a power consumption of approximately 5,800 W, rather than the single-phase connection used by the smaller models. The data logger can be read via the Ethernet interface; a time-limited trial version of the AtmoCONTROL software is available for download.

Capacity of the Memmert UN450 universal chamber

The internal dimensions are 1,040 x 720 x 600 mm; the external dimensions of the cabinet are 1,224 x 1,247 x 784 mm. There is space for up to 8 shelves; 2 electropolished stainless steel grids are included in the scope of delivery. The UN450 can be loaded with a total of up to 300 kg; each shelf can hold up to 30 kg, which is more than the smaller UN models, which allow 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 fully insulated stainless steel doors are secured by a 2-point locking mechanism with a compression door latch.

Selection guide: same footprint, different heights

Within the Memmert UN series with natural convection, the internal volume ranges from 32 to 749 litres. The UN450 and UN750 share the same floor space and differ only in their overall height, which is an important selection criterion where room heights are low.

If you require the maximum capacity within this footprint and have a room height of more than 1.72 m, choose the Memmert UN750 universal cabinet with 749 litres and 14 shelves. If a smaller volume with a smaller footprint is sufficient, the Memmert UN260 universal cabinet with 256 litres is the ideal alternative. The full range of climate chambers and incubators can be found under Climate Chambers & Incubators.

Distinction: natural convection versus forced air circulation, UN450 versus UF450

In addition to the UN450 with natural convection, LT Laborhandel also stocks the Memmert UN450 universal cabinet, the structurally identical large forced-air version with an electronically controlled fan. The UF450 actively distributes heat throughout the interior and reaches its operating temperature range from as low as 10 °C above room temperature, which ensures shorter heating times for densely packed batches of varying sizes. The UN450 deliberately avoids this and instead starts operating from just 5 °C above room temperature, with absolutely no air movement inside the chamber; this is the right choice for large quantities of material samples that are sensitive to dust or vibration. Both models share the same interior, housing and ControlCOCKPIT SingleDISPLAY, but differ in their ventilation principle and operating temperature range.

Safety in accordance with DIN 12880 for long, unattended processes

Process safety is crucial, particularly for large-volume batches that often run overnight or for several days. The UN450 features adjustable electronic temperature monitoring plus a mechanical temperature limiter of protection class 1 in accordance with 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. CE and EAC markings, as well as a UL test mark, are provided.

Installation, operation and disposal

The same spacing requirements apply to the operation of the UN450 as for the smaller models: a minimum of 15 cm from the wall, a maximum of 20 cm from the ceiling and a minimum of 5 cm to the side, either from a wall or an adjacent unit. Given a net weight of around 161 kg and the three-phase power connection, the installation site should be fitted with a suitable high-voltage power supply prior to delivery. The unit may be installed at altitudes of up to 2,000 m above sea level, at ambient temperatures of 5 °C to 40 °C and with a maximum relative humidity of 80 per cent, non-condensing. Electrically, the UN450 is designed for overvoltage category II and pollution degree 2; it must only be transported in an upright position. As an electrical appliance, the UN450 is subject to the Electrical and Electronic Equipment Act at the end of its service life and must not be disposed of with household waste.

Typical areas of application

With an internal volume of 449 litres, up to 8 shelves and a load capacity of up to 300 kg, the Memmert UN450 universal cabinet is designed for high-throughput applications where headroom at the installation site is also limited.

• Large-volume drying and heat treatment batches in industry and research
• Routine tempering, ageing and baking of material samples
• Material testing and quality assurance with high sample throughput
• Vibration-free heat treatment of dust-sensitive materials on a large scale
• Installation sites with limited headroom where a UN750 will not fit

Business case: racks, access control and process monitoring

The UN450 is supplied with 2 electropolished stainless steel grating trays as standard; the cabinet is designed to accommodate up to 8 racks, each with a maximum load of 30 kg. Options for process monitoring include a 4–20 mA current interface, fan speed monitoring, an additional Pt100 sensor and SMS alerts; for controlled access, there is a lockable door with a security lock. Those requiring a gas-tight version with various pipe penetrations can also have this configured. In addition, we supply base frames with levelling, as well as calibration, IQ/OQ/PQ services in accordance with DIN 12880 and maintenance contracts, including those accredited by DAkkS.

Frequently asked questions before purchase

Why does the UN450 require three-phase power?
A cabinet of this size requires significantly more heating power – around 5,800 W – than the smaller UN models; therefore, the UN450 is operated with 400 V three-phase power and 3 x 230 V without a neutral conductor, rather than a single-phase connection.

How does the UN450 differ from the UF450?
Both share the same interior, housing and control system; however, the UF450 also features an electronically controlled fan for active air circulation and has an operating temperature range that starts at 10 °C rather than 5 °C above room temperature.

How tall is the UN450 and will it fit under a standard ceiling?
The external dimensions are 1,224 x 1,247 x 784 mm; with a height of 1,247 mm, the UN450 also fits into rooms where the taller UN750, at 1,720 mm, would no longer fit.

What is the maximum load per shelf?
Up to 30 kg per shelf, with a total load of up to 300 kg for the entire unit when fitted with a maximum of 8 shelves.

What is the accuracy of the temperature control?
Despite the three-phase power supply, the same accuracy applies across the range as for the smaller models: 0.1 °C up to 99.9 °C and 0.5 °C from 100 °C, measured using a DIN Class A Pt100 sensor with 4-wire technology.

Is the UN450 suitable for long, unattended processes?
The mechanical temperature limiter, which complies with 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 processes running overnight or over several days.

Technical details

Contents of delivery

• 1x Memmert UN450 universal cabinet
• Factory calibration certificate (calibrated at 160 °C)
• Fully insulated stainless steel doors with 2-point locking (compression door seal)
• 2x stainless steel grating, electropolished

Regulatory information

The Memmert UN450 universal cabinet is registered with the Stiftung Elektro-Altgeräte Register (Stiftung EAR) under WEEE registration number DE 66812464.

Customised requirements & procurement service

Options available for the UN450 include a lockable door with a security lock, a gas-tight version with various pipe feed-throughs, and reinforced grating and perforated sheets. For process monitoring, a 4–20 mA current interface, fan speed monitoring, an additional Pt100 sensor and SMS alerts are available. In addition, we supply base frames with levelling, as well as calibration, IQ/OQ/PQ services in accordance with DIN 12880 and maintenance contracts. Do you require any of these accessories or assistance in selecting the right universal cabinet for your application? Through our procurement service, LT Laborhandel will be happy to assist you with procurement and configuration.