Taking Care of Your Environmental Chamber

Maintaining the condition of your environmental chamber
is essential to keeping it performing like new.
Image courtesy Percival Scientific

When your new environmental chamber or incubator arrives, fresh off the pallet, everything about the equipment is in top shape. Over time, through normal use, there are aspects of the equipment that can become worn, dirty, or otherwise compromised. This normal wear and tear, if left unchecked, can impede the proper operation of your chamber and cause its performance to deteriorate.

Percival Scientific, globally recognized manufacturer of plant growth chambers and other environmentally controlled chambers and rooms, posted a blog with some general recommendations that users can employ to make sure their equipment stays in good working order. You can read the full article, or a synopsis with key items provided below.

• Air cooled condensing units must have sufficient air movement across their condenser surface in order to function properly. As dust accumulates on the condenser, the chamber's ability to cool is compromised. You may need to use a small ladder of step stool to get access for inspection and cleaning. Use a vacuum to remove accumulated dust, not compressed air. The air quality at the chamber installation site will determine how often this inspection and cleaning should be performed. 
• Perform a similar check at the evaporator, the cooling coil inside the chamber. The requirements are the same. Remove accumulated dust with a vacuum.
• Chambers with cooling systems will have a condensate drain pan and a drain tube below the evaporator coil. Over time, dust and dirt (sometimes debris) can accumulate in the pan or restrict flow through the drain tube. Periodic flushing with warm soapy water will help keep the line and pan clean and clear.
• Various surfaces within the chamber will benefit from regular cleaning. This will help retard corrosion, accumulation of dirt, and growth of unwanted mold, etc.

There are more regular maintenance details, depending upon the features of the environmental chamber. Many users, already burdened by the time demands of their work, contract with outside parties to perform regular cleaning, checking, and calibration. Whatever your system of performing regular preventive maintenance, keep it in place and working to maintain the chamber performance you expect.

Share your environmental chamber questions, concerns, and challenges of all types with the equipment specialists at Atlantic Technology Group. Their expertise will leverage your knowledge and experience into effective solutions.

Laboratory Ovens and Incubators Overview

BMT manufactures an extensive line of drying ovens and incubators for laboratory and processing applications. Differing product series are tailored with construction and operational features for applications prevalent throughout the sciences and research. The video will give you a quick tour of the product offering.

More detail is available from the lab equipment and planning specialists at Atlantic Technology Group. Share your requirements and challenges with them and leverage your own knowledge and experience with their product application expertise to develop an effective solution.

Controlled Environment Room Air Flow Matters

Matching controlled environment air flow pattern, velocity,
and volume to the application is part of delivering a well
performing system
photo courtesy Percival Scientific

Environmental chambers, whether of the reach-in or walk-in variety, all rely on the movement of air within their controlled space to attain performance specifications. Various manufacturers will employ differing strategies for chamber air movement, and the manner in which their designs disperse air flow throughout a chamber of any size can have an impact on the work or process held within the chamber.

This article is about controlled environment rooms, but much of what is included here is also applicable to smaller sized chambers.

The design of air flow in a controlled environment room can be impacted by a number of factors, some of which may be based on specific application requirements, and others that may be influenced by cost, production simplicity, or other factors unrelated to the performance goal of the equipment.

What aspects of controlled environment room air flow bear on performance?

• Velocity - In the common usage of the term when referring to air flow, the speed of the moving air. Depending upon the air moving equipment arrangement and any dispersion devices, such as perforated suspended ceilings or wall plenums, air velocity can vary throughout a chamber. Users should consider how their work may be impacted by air flow velocity. The storage of material in closed and sealed containers may be impervious to air velocity effects because the "product" within the container is not in contact with the moving air. Plants and insects, on the other hand, are an example of items that may be significantly or severely impacted by air velocity. Higher air velocity at a chamber location exposes that location to more air per unit of time. Desiccation is one possible concern that is exacerbated by increased air velocity. Higher velocity can also be beneficial, even necessary, for some applications. Rapid cooling or heating of materials placed within a chamber is enhanced by increased air movement across the material surface.
• Volume - The volumetric flow of air through a controlled space or chamber is needed to transfer heat to or from the space in order to maintain temperature control. Much of the air in a controlled environment room is recirculated, with cooling, heating, and in some cases moisture applied to condition the air in the room to the setpoint. The volume of air movement is loosely related to velocity, so increasing volume will result in an increase in velocity unless other design changes are made with respect to how the air is dispersed throughout the room. Higher volume, or turnover rate, contributes to better temperature uniformity in the room. As with velocity, there may be application specific requirements for low air movement. Keep in mind that low air movement creates challenges to the attainment of close temperature control and uniformity. 
• Pattern - The way in which air is distributed throughout the controlled environment room can impact system performance once materials are placed in the room or process work is commenced. Empty chambers generally perform well, regardless of the air flow pattern, because there is little in the way of a load on the system and no solid materials in place to block or redirect air flow. Consideration should be given to the way in which air is dispersed throughout the work area. Loading patterns for stored product or the placement of work in process should be accommodated by the air flow pattern.

Matching the right air flow characteristics to the work to be achieved in a controlled environment room will result in better overall performance, not just when empty chamber tests are conducted, but when real work is being accomplished. 

Share your environmental chamber and controlled environment room requirements and challenges with application experts. The combination of your own experience and knowledge with their specialized technical expertise will yield an effective solution.

Cell Culture Incubators - They Sure Don't Make 'em Like They Used To

Cell culture incubators
Courtesy Esco

Incubators have been a mainstay of many applications in life science research and clinical testing for many many years. The term incubators can refer to a broad range of manufactured products, but let us narrow the focus of this article to equipment used for cell culture.

Equipment from decades ago was primitive when compared to what is available today. One early model sported all copper construction, not to impede contamination, but to enable its construction method using soldered seams. This particular water jacketed incubator was also heated by a gas flame and used a mercury filled temperature switch to control temperature within a few degrees of a setpoint.

Why were incubators water jacketed?

There were two valid design reasons for building a water jacketed cabinet. Early on, heating options were practically limited by cost and capability to the delivery of heat in concentrated areas. Since temperature uniformity throughout the work zone is probably the most important performance consideration for an incubator, it was necessary to evenly disperse the concentrated heat throughout the chamber in a manner that did not create undesirable variance. One way to accomplish this was, and still is for some manufacturers, to surround the chamber with a water filled "jacket". The water served as a heat distributor through natural convection.

The second reason for water jacketed design is to provide an interior environment with very little air movement. With all the chamber wall surfaces maintained at the same temperature, the heat input to the work space is uniform, and robust air circulation to provide an even temperature distribution is not needed. Air movement tends to promote desiccation in cell culture media, so lower air movement is generally better. Many cell culture operations also require very high levels of relative humidity, and lower chamber air movement will tend to promote a higher moisture level in the contained space. It was common to place a tray of water in the base of the chamber to saturate the air.

Not surprisingly, manufacturers continually strive to improve their products. New or improved technologies for measurement, control, or construction related to incubator design eventually reach a price point that enables their practical incorporation as a product improvement. Improved temperature controllers, sensors, and heater designs have enabled the production of incubators that deliver performance comparable or superior to water jacketed designs, but without the water jacket.

To grow, cells have the same needs today they had decades ago. Manufacturer's application of technological improvements to continually enhance their products has provided real benefits to researchers and other users of cell culture incubators. Higher reliability and lower requirements for attention from the user has increased lab efficiency.

Get more information about the useful features incorporated in the latest cell culture incubator designs from product specialists. Share your concerns and challenges with them, combining your own process knowledge and experience with their product application expertise to develop an effective solution.

CO2 Cell Culture Incubators from Atlantic Technology Group, Inc.

CO2 Incubator Selection Guidance

Laboratory CO2 Incubator
Courtesy Esco

CO2 incubators are a mainstay of laboratory scale cell culture. Most applications call for operation at +37 degrees Celsius, 5.0% CO2 concentration, and 85% to 95% relative humidity.

Selecting the right incubator to provide the cell culture environment calls for consideration of not only the conditions to be achieved for temperature, relative humidity, and CO2, but how those conditions will be maintained. Stability and accuracy are important, and the way in which an incubator achieves the environmental conditions is worth examination when selecting an incubator. Additionally, determining what operational features and capabilities might be beneficial for increasing workplace efficiency or reducing maintenance can help in selecting the incubator that will best serve your needs.

Esco, globally recognized innovator in the design and manufacture of a range of laboratory equipment, has produced a guide for selecting CO2 incubators. It provides knowledge and guidance about chamber construction, sensors, heating, chamber air movement, filtration, decontamination, and more.

The guide is provided below for your use. Share your laboratory equipment requirements and challenges with lab equipment specialists, combining your own process knowledge and experience with their product application expertise to develop effective solutions.

Choosing a Laboratory CO2 Incubator from Atlantic Technology Group, Inc.

Anaerobic Chambers for Biological Applications - Some Basics

Vinyl anaerobic chamber, Type A.
One of many variants manufactured
by Coy Lab Products

Anaerobic chambers are used in life science research to study microbial life that thrives in environments with very little or no oxygen. The essential arrangement includes an environment enclosure, transfer airlock, gas exchange system, sample handling means (usually gloves integrated into the enclosure),and a scrubber for removing trace oxygen from the chamber interior. Other fixtures and accessories can customize an anaerobic chamber for particular use, and might include shelves, storage cabinets, or incubator chambers.

Maintaining good environmental performance from an anaerobic chamber calls for attention to various seals and other mechanical features that are essential to proper operation and subject to normal wear and tear. Below, in question and answer form, are some basics for understanding and using a Coy anaerobic chamber (excertped from http://coylab.com/ts-anaerobic-faq.htm, with a little editing for form)

How much gas can I anticipate using when I operate the chamber on a routine basis?

This is a difficult question that does not have an exact answer. The exact answer will depend on how many times you enter the Chamber through the airlock. On an average, suppose you entered the Chamber five times a day and were using "K" size supply tanks (304 cubic feet) for nitrogen gas and "A" size supply tanks (230 cubic feet) for the gas mix. If you have an automatic Airlock, your nitrogen gas will last approximately 47 days and your gas mix will last approximately 72 days. These figures assume you are vacuuming the Airlock to 20 inches (0.69 Kg/sq. cm) of mercury. If you have a manual Airlock, your gas mix will last approximately 25 days, assuming you vacuum the Airlock to 29 inches (1 Kg/sq. cm) of mercury. These figures are calculated for Airlock use only. They do not include gas usage during Chamber purges. Test show in a static environment (no airlock operation/transfer) the chambers will consume .2-.4% hydrogen per day.

How often, at what temperature and for how long do I rejuvenate my catalyst?

Rejuvenating the Catalyst is very important in keeping the Chamber in an anaerobic condition. Rejuvenating the Catalyst a minimum of once a week at 125-200 Celsius for two hours is recommended. Included in the Chamber package are 2 sets of Catalyst Stak-Pak. Replace the Catalyst you rejuvenate with the extra set. Then your Chamber will always have fresh Catalyst. If you have an extremely busy Chamber, you may need to rejuvenate the Catalyst more frequently.

Why does my chamber lose its anaerobic condition over a period of time?

There are a couple of variables that must be considered to answer this question. First, does your Chamber have a leak? (Noted by the Chamber top collapsing over night.) Second, is the catalyst fresh, have they been rejuvenated?Once these variables have been considered and eliminated from the probable cause, concentrate on the hydrogen content in the Chamber. Deficient hydrogen content is usually the cause for losing anaerobic conditions in the Chamber. Oxygen is constantly entering the Chamber by Airlock use and diffusion through the PVC walls. Without the hydrogen the catalyst cannot react to remove the oxygen. If you do not regularly use the Chamber, once a week manually vacuum the Chamber about half way and introduce gas mix (containing hydrogen) into the Chamber. You must keep in mind the dilution factor when the gas mix enters the Chamber. If you are using a 10% hydrogen gas mix your Chamber will not contain 10% hydrogen. It will be diluted to approximately 6% or 7% Hydrogen. (see section 2.0). Coy Labs Oxygen/Hydrogen Analyzer can be used to display the amount of hydrogen in percent that is present in your Chamber. Also, the Analyzer has an alarm that indicates when the hydrogen content goes below 1%. If you have exhausted every probable cause and your Chamber still loses its anaerobic condition, test your gas mix for hydrogen content. We have seen and heard of gas companies that do not comply with customer specifications.

How do I know my catalyst is working and how often should I replace it?

A good test to determine if your catalyst is working is to place a tray containing catalyst inside the Airlock. Place a thermometer in direct contact with the catalyst. Then manually vacuum the Airlock (manual or automatic) to 25" (0.53 Kg/sq. cm) of mercury and back fill it with gas mix containing hydrogen. If the catalyst is working correctly, the temperature will increase due to the reaction of catalyst, oxygen, and hydrogen. Temperature will increase about 10 degrees Celsius over 10 to 15 minutes. Coy recommends catalyst replacement on a yearly basis or if the catalyst does not respond to the above test.

Where do most leaks occur in the anaerobic chamber?

Leaks can occur anywhere in the Chamber but most will be present around work areas. Before you begin leak detection, you must first make sure the Chamber contains your normal amount of pre-mixed gas. A towel saturated with isopropyl alcohol, and allowed to sit in the Chamber for a few minutes, will assist in detecting the very small (slow) leaks. With your gas leak detector, check the following areas first:

• Gloves and cuffs
• Along chamber sleeves
• Under work pad
• Around airlock seals
• All corners of the chamber

Share your lab equipment questions and challenges with the laboratory and process equipment specialists at Atlantic Technology Group. The combination of your own experience and knowledge with their product application expertise will create an effective solution.