Instrument noise, particularly from cooling devices, can take its toll on laboratory workers. “Chillers can be quite noisy,” observes Bob Bausone of PolyScience (Niles, IL).Noise interferes with conversations but can also induce stress, leading to irritability, anxiety, and poor performance. Lab workers are particularly susceptible, as decibels in busy labs can add up quickly from refrigerators, freezers, aspirators, fume hoods, and chillers.
WhisperCool™ Environmental Control System technology, developed by PolyScience and incorporated in several of their refrigerated circulating baths, controls noise by optimizing fan speed and compressor operation based on the actual overall cooling demand. “As demand decreases, so does fan speed and the demand on the compressor,” Bausone says. Under conventional temperature control, fan and compressor run alternately (and mostly) at full speed mode, then turn off and on again.
“Most cooling applications do not demand all-out operation,” Bausone explains. “If you’re controlling the temperature of a laser, the chiller needs to operate full-tilt only when the laser is active. When the laser shuts down, the cooling system can slow down too.” WhisperCool also reduces energy consumption and stress on the compressor, prolonging its life and minimizing the need for servicing.
Weight and complexity
According to Vero Tabares, director of business development at TriTech (Edgewater, MD), the most often-heard complaints about chillers are about their complexity and weight.
While noting the commendable size reductions in many lab instrument categories, he believes miniaturization comes at a cost, particularly for chillers and baths. “People are becoming more comfortable with technology like tablets and smartphones, but when it comes to the lab, they want to focus on the experiment and not on setting up instrument conditions.” Many manufacturers, he adds, promote features that make a difference for just a small percentage of users. “This is true not only for chillers and baths, but for lab equipment in general.”
Given the persistent issue of bench space or lack thereof, it is not surprising that customers would grumble about the size and weight of chillers. With chillers frequently moved around within a lab, or from laboratory to laboratory, Tabares notes that “most lab workers are not weight lifters, constantly moving 24-pound objects from here to there.” His advice to manufacturers: “Make them smaller and lighter-weight.”
Size and weight reductions eventually run up against the laws of nature, however. “Smaller machines do not necessarily weigh less. In many cases, it’s impossible to reduce weight due to the limitations on the components. You can’t defy physics or gravity,” Tabares says. Nor does he expect OEMs to replace solid steel cabinet materials with space-age carbon fiber or titanium. “But the use of aluminum alloys will make these products lighter. After all, they are not subject to vibrations from an internal motor like shakers or spinners.”
Tabares believes that customers can save substantially by acquiring refurbished chillers and baths instead of new units, and at a very attractive riskbenefit ratio. “Chillers and baths use basic components that are not prone to breaking down. Many are still in operation after a decade or longer with no serious issues. It’s not the same as with a water-jacketed incubator or carbon dioxide-injected incubator, which require very precise controls. Chillers and baths are much less temperamental.”
Compact, powerful chillers
Rotary evaporators, incubators, reaction vessels, and analytical instrumentation require heat removal and rely on precise temperature control. “Without the right temperature control solution the process may be ineffective or the machinery may even be damaged,” says Kelly Gibbons, marketing coordinator at PolyScience (Niles, IL).
Gibbons recognizes both the bulkiness and complexity issues. To address physical heft she notes that chillers “with a lot of cooling power” are the most desirable. And she agrees with Bausone that, since these products are generally viewed as accessories, users do not want to spend a lot of time with setup, operation, and maintenance. “Manufacturers must consider ease of use, plus environmental friendliness and cost when designing chillers.”
PolyScience has met these challenges with a line of affordable, low-temperature, and compact but powerful chillers—the LS-Series, LM-Series, and the MM-Series—that provide up to 1290 watts of cooling at 20°C with ±0.1°C stability and a variety of other features. The LS-Series products can cool multiple rotary evaporators and are available with either a centrifugal or turbine pump.
When moderate rather than robust heat removal— with more precise temperature control—is required, refrigerated circulating water baths are the ideal product choice, says Gibbons. “When considering this type of cooling device purchasers should consider temperature range, temperature stability, pump capabilities, footprint, working access, and any features that make the circulating water baths easy to use and maintain.”
Desirable features include multistep temperature ramping, icon-driven touch screen operation, builtin electronic keypads, and networking potential to document temperature settings.
Heating and cooling
Heating units have been undergoing changes as well. Earlier this year, Grant Instruments (Cambridge, UK) unveiled a new line of heating circulators, Grant Optima™, which provides temperature stability of down to ±0.01ºC and excellent uniformity (±0.1 to ±0.05ºC). Grant designed Optima for use with the company’s five new stainless steel baths, three plastic baths, and models in its refrigerated bath and circulator product lines.
According to Emma Hewson, product manager at Grant, her company “worked closely with customers during the design, prototyping, and development stage of the Optima” products to account for workflows in modern labs involving heating and cooling. As a result, Grant has improved design and usability features, and built in more programmability “so the user can set up a simple or highly complex procedure and leave the equipment to do its job while they do theirs.”
Optima incorporates several advanced features, such as a full color screen with icon-driven menus, USB interface for PC programming (through Grant’s Labwise™ software), and an integral pump for external fluid circulation.
Angelo DePalma is a freelance writer living in Newton, NJ. You can reach him at firstname.lastname@example.org.