We compared four models of large refrigerated incubators available from major laboratory instruments suppliers. We were interested in understanding the differences between the standard models and the models that are in the middle price range for these instruments.

VWR symphony Low-Temperature / BOD Incubators (VWR) Precision model 30MR refrigerated incubator (Fisher) Refrigerated incubators with forced convection KB 720 Binder (VWR) Incubator Stability Chambers Thermo model 3920 (Fisher)
Accuracy ±0.2°C at 37°C ±0.2°C ±0.1°C at 5°C; ±0.2°C at 40°C ±0.1ºC @ 25ºC to 37ºC
Heat-up time 35 min. to 37°C Unknown Unknown Unknown
Recovery time 12 min. to 37°C; 15 min at 50C Unknown 2 min. at 37°C; 12 min at 4°C Unknown
Temperature range 0 to 60°C 5 to 70°C –5°C to 100°C 0°C TO 60°C
Disinfection Not possible Not possible Disinfection at 100 °C Not possible
Temperature setting accuracy ±0.1°C Unknown ±0.2°C at 5°C; ±0.2°C at 25°C; ±0.2°C at 37°C; ±0.1°C increments
Temperature Uniformity ±0.5°C at 37°C; 1.4°C at 50°C ±0.4°C at 5°C; ±0.5°C at 25°C; ±0.5°C at 37°C ±0.1°C ±0.3°C @ 25°C to 37°C
Capacity 700 l (24.7 cu ft) 849 l (30 cu ft) 698 l (24.7 cu ft) 849 l (29 cu ft)
Temperature control mode Advanced Adaptive Microprocessor Control with Jog-Shuttle Knob (Turn and Push) Hydrolic temperature control thermostat microprocessor controller; RS 422 interface for communication software APT-COM™ DataControlSystem Microprocessor PID
Temperature sensor Equipped with RS-232C Interface for Monitoring and Controlling with PC; Sensor PT100 ±0.1°C and Storage Function (Temperature and Time) Analog temperature control Programmable controller with intelligent temperature control and weekly program timer RTD sensor
Shelves Comes with 3 stainless steel and up to 40 shelves can be installed in total Maximum of shelves is 6 (can not install any additionnal ones) Comes with 2 stainless steel racks and accommodate up to 15 racks Comes with 6 adjustable heavy-duty solid stainless steel shelves. Accommodate up to 19 shelves in total
Compressor Unknown Standard compressor with standards fluids Unknown compressor Standard compressor with standards fluids
Refrigeration CFC-Free (134A) Refrigeration System. Intelligent Control of Refrigerator Unknown Adjustable ramp function via program editor. Patented DCT™ refrigeration system assuring temperature accuracy and reproducible results in both heating and cooling situations. Non-CFC R134A refrigerant
Warranty Two-Year Parts and Labor Warranty Unknown Unknown One Year Parts and Labor Warranty
Air circulation “Forced air mechanical convection - horizontal air flow; a 3.3 cm (1.3”“) stainless steel ventilation cap” Mechanical convection technique; top mount fan with diffuser panel for gentle circulation of air inside chamber Adjustable fan speed ; No condensation will appear in the inner chamber during cooling “Directed airflow system; forced air from right to left (more efficiently maintains a uniform temperature as opposed from top to bottom)”
Doors Two doors (outer one solid; the inner one tempered glass door) One door solid or glass “Two doors (Inner glass door)” One glass
Over-temperature protection Over-temperature and over-current protection by sensor error detection Built-in high temperature safety “Independent adjustable temperature safety device class 3.1 providing full protection against chamber over-temperature with visual and audible temperature alarm” Temperature safety: Sensor & Controller by Thermostat with audible/visual alarm
Exterion construction Powder-coated steel exterior Powder-coated steel exterior Unknown 18 gauge cold-rolled steel powder coated
Interior material Stainless Steel (#304) Aluminum interior Stainless steel Type 304 2B finish stainless steel
Insulation Glass wool insulation Glass wool insulation (2 inches) 60 mm insulation; glass wool and insulation foam “2.0”“ (5.1cm) thick non-CFC foamed-in-place polyurethane cabinet insulation”
Outer door gasket High temperature grade foamed silicone rubber door gaskets Unknown Very tight door closure with 2-point door latch Four-sided vinyl compression
Drain no no yes 3⁄8“” FPT & 3⁄8“” O.D. P-trap right rear
Internal outlet Internal 110V outlet for auxillary equipment require installation by an electrician Internal duplex eletrical outlet require installation by an electrician Possible Possible
Access ports No (but one can modify the instrument) Optional Access port with silicone plug Ø 30 mm left side present
Load per rack Unknown Unknown 45 kg 22.7 kg
Electrical requirement 120V 60Hz 120V 60 Hz 17.9 Amps 115V 50/60Hz 120V 60 Hz 16.0 Amps 3 Wire (including ground)
Energy consumption at 37°C 2400 W 2150 W (but 700 W to maintain 25°C) 510 W at 37°C to 1350 W 1600 W
BTU output Unknown 7338 BTU / hour Unknown 5500 BTU / H
Dimension exterior 93.5 cm W x 102.6 cm D x 199.9 cm H 80 cm L x 91.4 cm W x 237.5 cm H 123.4 cm W x 86.7 cm D x 181.6 cm H 96.5 cm W x 81.3 cm D x 224.8 cm H
Dimension interior 80 cm W x 70.1 cm D x 125 cm H 61.6 cm L x 76.2 cm W x 182.9 cm H 125 cm W X 89 cm D X 192.5 cm H 78.7 cm W x 68.6 cm D x 152.4 cm H
Shipping weight 313 kg 344.7 kg 262 kg 385.6 kg
Clearance rear 20 cm 76 cm 100 cm 76 cm
Clearance side 100 cm 76 cm 100 cm 3 cm
Noise level unknown < 65 dB 53 dB(A) < 65 dB
Legs or castors Unknown no castors 4 castors (2 with brakes) Swivel locking casters