Laboratory Equipment

Ovens are an important piece of laboratory equipment that serve a multitude of purposes including drying, sterilizing, curing, standard preparation and so much more. There are such a large variety of ovens on the market that it can be hard to determine which ones would best suit your procedural needs. Here is a breakdown between natural and forced convection ovens.

What is Convection?

Convection ovens are widely used by laboratories, but what exactly does convection mean? Convection is the movement of heat through a medium such as water or air. Thus, convection is important because it accelerates the heating process.

Natural Convection

Natural convection occurs when a substance is heated from a heat source and thermal expansion occurs. For example, when a pot of water is placed on a burner of a stove and it is heated to boiling. The molecules closest to the burner heat and become less dense. This causes them to rise up in the pot which allows the denser particles to then be heated. When the molecules are heated, they move faster and collide. This movement causes a gradual heating within an enclosed area.

Natural Convection Ovens are also called gravity ovens because they rely on natural air circulation to heat the interior of the oven. The temperature stays fairly stable as air flows throughout the chamber.

Pros with a Natural Convection Oven

If your process requires general techniques like drying or curing, there a lot of upsides to purchasing a natural convection oven.

• They are a very economical choice because the overall cost is low and the variety of uses that they can accommodate are high
• They offer high temperature ovens that have an extremely high maximum temperature. The Yamato DR200 can even offer temperatures from 300°C to 700°C!
• The Yamato Scientific natural convection ovens have great safety features like overheat protection and self-diagnostic capabilities.

Cons with a Natural Convection Oven

Consider the cons when purchasing a natural convection oven.

• Natural convection ovens cannot offer precise temperature uniformity.
• Their rate of drying is slower than a forced convection oven.

Forced Convection

Forced convection is when fluids or air is forced through a system in order to heat or cool it. An example of forced convection is a fan pushing warm air through an enclosed space to heat it or a pump that pushes water through a system to heat the area.

Forced Convection Ovens are also called mechanical ovens because they have a built-in motorized fan or pump to assist with heat distribution.

Pros with a Forced Convection Oven

You want to use a forced convection oven if your process requires higher accuracy and temperature uniformity. There are numerous pros to using a forced convection oven.

• They offer a more even heat distribution than natural convection ovens.
• If you work in a production facility where it is vital to process samples quickly and effectively, a forced convection oven can dry samples at a much faster rate than a natural convection oven.
• If you work with samples that have a high moisture content, a forced convection oven is the right choice because you need the heat capabilities to ensure total evaporation of the moisture.
• They are already very popular and have been proven effective in almost every laboratory industry including suspended solids testing, asphalt testing, drug metabolism, serum protein analysis, plastic curing, vulcanization studies and much more.

Cons with a Forced Convection Oven
There are a few downsides to consider regarding the forced convection oven.

• Yamato’s forced convection oven heats samples in a vertical direction. The bottom of the oven is heated and then that heat is forced upwards towards to rest of the oven. Improperly loading the oven or placing too many trays in it can reduce and restrict the airflow needed for temperature uniformity.
• Due to the motorized component that specializes these ovens, they do consume more energy than a natural convection oven.

Key Points to Consider Before Purchasing an Oven

Take the time to analyze your process before purchasing an oven to make sure you obtain the one that best suits your needs.

• Determine the minimum and maximum temperature that you need. Choose an oven with a maximum that is higher than the one you need. This helps ensure accuracy by keeping the temperature to a more median range. It also gives additional opportunity for different uses in the future.
• Measure the bench space available in your laboratory. Ovens come in a variety of dimensions so you want to make sure to buy one that will fit in the space that you have.
• Find a style that is energy efficient to both reduce your footprint and to remain cost effective to use. Also find a model that is easy to clean to avoid contamination.
• Look for a variety of features that are beneficial to you and your laboratory like auto start, power failure recovery, and data acquisition. The Yamato Programmable Ovens are a great choice for individualized programmable features.

If you have any questions regarding our selection of natural and forced convection ovens, make sure to contact us.

For over 40 years, Lab Pro Inc. has been committed to delivering the highest quality lab equipment such as natural and forced convection ovens, lab supplies, chemicals, and cleanroom PPE apparel to medical device and electronic manufacturing laboratories worldwide. To learn more, visit the biggest Lab Supply showroom in California, or contact us online or at 888-452-2776.

References

“Convection.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., www.britannica.com/science/convection.

“Laboratory Oven.” Yamato Scientific America, www.yamato-usa.com/products/ovens/.

“Your Complete Guide to Buying the Perfect Lab Oven.” Yamato Scientific America, www/laboratoryapp.com/your-complete-guide-to-buying-the-perfect-lab-oven-guide-pdf.