Most laboratory workers view ovens almost as utilities, using them principally for drying glassware and heat-resistant equipment, regenerating desiccants and catalysts, gently heating samples, and curing or preparing materials and composites. Over 50 percent of our respondents have at least three or more ovens in their lab.
Common laboratory ovens maintain temperatures ranging from just above ambient to about 300° C and are ubiquitous in chemistry, biology, pharmaceutical, forensics, and environmental labs. Units operating at temperatures above 300° C are normally dedicated to specialized applications in physics, engineering, electronics, and materials processing. Typical lab ovens use four to six cubic feet of space and are located on bench-tops or stacked atop another oven; other units may be much larger.
Oven applications are expanding beyond simple drying. Chemists use ovens for thin film battery drying and solvent removal; the food industry desiccates samples inside ovens to determine moisture content; electronics and defense labs process integrated circuit boards and other components inside ovens; and there are many more applications.
Which of the following disciplines best fits the product application in your lab?
|Heating and drying||49%|
Circulation ovens (the most common in labs) come in two types: gravity convection or mechanical (forced) draft. The former often suffer from temperature inhomogeneities and stagnation, which is why ASTM and AASHTO standards call for forced draft ovens.
Which type(s) of lab oven are you currently using? (Check all that apply)
|General Purpose Oven||39%|
|Mechanical Convection Oven||19%|
|Gravity Convection Oven||13%|
One emerging trend in laboratory ovens is increasing demand for high-temperature ovens from engineering and materials processing labs along with energy efficiency, which is important mostly to lab supervisors and facility managers.
According to one expert, the single most important consideration for a potential oven purchaser is the type of temperature controller employed. Types of controllers include simple on-off, proportional, and proportional integral derivative (PID).
Temperature control, precision temperature distribution, and temperature ramping/programming are desirable features in an oven but not required for common drying applications. High-end ovens control temperature at 27 points inside the box, whereas ASTM standards require only nine-point control.
Until recently, almost nobody cared about energy efficiency but today it’s high on the list of desirables. The increase in energy costs is driving the costs of operating lab ovens higher. Laboratory ovens — used for heating and drying processes — frequently run for lengthy, high temperature protocols and use large amounts of electricity. Some units run 24/7 to be prepared for rapid testing. Selection of an oven based on the energy footprint within the laboratory can provide significant cost savings over time.
Where lab space is at a premium, purchasers should also consider the unit’s size and stack-ability.
Our respondents’ top 10 factors in their decision to buy a lab oven:
|Ease of Use||68%|
|Low maintenance / operating costs||68%|
|Temperature ranges ambient +40C to 200C / 250C||41%|
|Service and support||33%|
|Smallest footprint possible with a large interior||30%|
|Controlled airflow to provide uniform temperature heat distribution||29%|
Other factors identified by respondents included: power requirements, ease of installation, availability of accessories / options, exhaust ports and dampers, and tightly-controlled level of contamination.
For more information on lab ovens, visit www.labmanager.com/lab-ovens