Every standard laboratory should feature a water bath and chiller for the primary purpose for which they are designed – heating and cooling. Interestingly, baths do more than just heating fluids which makes them essential for other activities, including sterilization of equipment, hybridization, and degassing.
There are tons of options to choose from when it comes to water baths, especially, and having a handy guide would help you make a decision faster and without regrets. With that said, this is a simple yet elaborate guide to assist you in making the best choice for a bath/chiller.
Factors to Consider When Purchasing a Water Bath
Functionality may be the first thing that comes to mind when the decision to purchase a water bath is made, but that alone is not enough. Water baths come in different sizes, require different conditions for optimal performance, and give different outputs. This shows that "functionality" is a vague standard for getting a water bath. If you consider getting one, these are some of the questions you should be asking or Googling.
●What is the temperature range installed in the bath?
Every water bath has a limit to heat before it starts to overheat or give off a warning. If you need a basic bath that heats up to a reasonable level, say, 100 degrees Celsius, you can go for any of the regular ones or analog baths. With a digital bath, you get more defined settings, so knowing what you would be doing in advance would help you decide which to get for the laboratory.
●How much power does it require to stabilize the unit for optimal performance?
Having figured out the temperature range, you would be using more frequently, it is also necessary to find out how much power is required to heat the bath to that level. Some water baths require more than a couple of volts to heat up and then stabilize. This information should be available on the manufacturer's guide or product description.
●How precise and stable is the heating process?
Water baths typically feature an error range, but anything within ±0.2 °C is usually acceptable and negligible. As expected, baths with a more precise and uniform heating process cost fairly more than those with wider margins due to the expensive thermometers installed, but that doesn't make the others non-suitable. The decision on which one to purchase now borders on what exactly you need it for and how much you're willing to spend just for accuracy.
Procedures that do not require absolute uniformity can be easily carried out in water baths with a little less precision, but this can be reduced by simply placing a lid over the unstirred bath.
●What type of warning system does the bath have?
Any equipment that produces heat requires extra caution, and even with periodic monitoring, things could go out of hand if there is no system to forestall ugly events. This is why water baths are built to house a warning system that visibly or audibly alerts those around when it exceeds a certain temperature. Depending on the nature of your work and the surrounding, a particular warning system may be preferred to the others.
●What additional accessories does the bath come with?
Is the bath or chiller accompanied by a lid that fits? Are there optional racks that can be purchased for the unit? Most racks are designed from stainless steel because they are placed in the heater, but not all companies offer multiple racks, so you would want to confirm from the production company if this is an available option. Additionally, not every bath comes with a lid so depending on what you would be using yours for, check with the store before purchasing one.
●What is it made of?
Water baths can be made from a couple of different materials, including steel and plastic, and while some materials may look more aesthetic than others, it doesn't guarantee durability. Typically, stainless steel baths are more durable and, by implication, more expensive than plastic baths, so your budget would also influence your purchasing decision. The average lifespan of a water bath is 4 to 6 years. However, this can be extended by another 4 to 6 years if adequate care is taken.
●What other lab purposes would the bath be used for?
If your primary purpose for getting a bath is to perform tasks like sonochemistry, degassing, dissolution of fluids, or even high-intensity cleaning of laboratory equipment, what you want to put your money on is an ultrasonic bath. These baths are built for extreme heating activities, and one advantage they have over other types of baths is their ability to regulate heat more precisely rather than working with a range.
For culturing or hybridization, then you may want to consider a reciprocating bath. Knowing that growing cultures require shaking alongside heating, reciprocating, or "shaking," water baths were designed to shake up the culture while heating evenly. Several baths of this nature come with added features that allow you to regulate the intensity and direction in which it shakes. Some non-reciprocating water baths are also able to serve this purpose by offering a detachable shaking bath. This makes them more versatile, but they may not feature some options that come with designated reciprocating baths.
●What are the dimensions of the unit?
The purpose for which a water bath is being purchased is an important factor to look at when checking out the bath's qualities. How hollow or wide is it? How much weight can be placed in it without running into issues?
As mentioned earlier, baths and chillers come in different sizes, and these sizes would determine their prices, how much voltage they would require and how well they can heat evenly.
After answering all six questions, you may realise that one bath may not serve you adequately because of the wide variety of activities performed in the lab. Depending on your budget, you may or may not be able to purchase more than one at a time. Nonetheless, it is advisable to get one that serves your primary purpose so take a moment to evaluate all the tasks you need to perform and which ones would be designated to a bath.
