Many industries require high specification temperature controlled units (fridges, freezers & cold rooms). Due to the size of the market, there are a great deal of brands and product lines to choose from, with factors such as temperature range, stability, accuracy, and price all factors to consider. For some, it can be quite overwhelming scouring the abyss of the internet for the right product and therefore, the aim of this guide is to provide a basis that users can refer to in the search for a temperature controlled unit.
Of course, the desirability of various factors will differ for each buyer based on the industry and application. The requirements of the products that will be stored inside, as well as industry regulatory requirements are two prime factors that may affect any purchasing decision.
Performance metrics are the key area most buyers will want to look at first to ensure these meet their requirements. Temperature range is probably the best place to start- temperature controlled units can come in the form of a +4°C fridge right through to a -180°C cryogenic liquid nitrogen freezer. The temperature range required will of course depend on the products or samples that will be stored inside.
Temperature stability is the second performance metric to review. Stability indicates the percentage of potential error in the measurement. The quality of various models will differ, so for the highest reliability control- it is better to purchase a system with a good level of stability. The temperature stability is critical for ensuring the measurement accuracy, and for some industries and applications- the unit needs to be as accurate as possible.
Moreover, temperature uniformity is an important variable in the buying process. This refers to the variation in temperature between different points within the chamber interior. The importance of uniformity to a user can differ based on the application, but for highly sensitive contents it is important to minimise the discrepancies between temperature measurements within the chamber and keeping it as consistent as possible.
The final key performance metric that should be evaluated is temperature accuracy. The accuracy of a temperature controlled unit is essentially how closely it reads to a calibrated piece of equipment. For example, to establish the accuracy of a data logger, results must be compared to those of a calibrated device. Temperature accuracy is typically displayed as a plus/minus value.
The environmental impact of the temperature controlled unit is increasingly a key factor in the buying decision making process. With global warming a very real and present problem, searching for a unit that utilises a refrigerant gas that complies with regulatory guidelines should be a priority, this is usually displayed as the Global Warming Potential (GWP). ALS products for example, use the R290 refrigerant- which is highly desirable due to its low rating of 3 GWP (well below the threshold of 150). The shift to cleaner energy sources means that buyers should aim as low as possible for GWP for both ethical and future proofing purposes (regulations will only tighten).
Furthermore, power consumption is another factor that will affect any impact on the environment. Sourcing a low energy product will further reduce the carbon footprint and also save money for the user through lower energy bills. Similarly, product life span benefits both the user and the planet, longevity means new units do not need to be purchased and removes the need for harvesting of further raw materials and production emissions and ensures that redundant units will not lie in waste.
There are also a few practical factors to consider, such as the size of the unit- is it going to fit the desired area? Max capacity- does it have adequate capability? Wattage- does the unit require more energy than there is available? And of course, budget. High specification fridges and freezers are no small purchase, and often more than one unit is required, so of course budget matters. Usually, higher cost temperature controlled units maintain the price due to offering enhanced performance and reliability. If a user purchases a cheap, low budget option, it must be noted that the likelihood of poorer performance, shorter life span and need for repairs will increase.
When purchasing a high specification temperature controlled unit such as a fridge or freezer it is also important to consider the distributor. The distributor will provide on-going after sales support, maintenance and repair. Service contracts are highly beneficial because routine maintenance will increase the life span of the unit and prevent costly issues. Security features will also be required for some- accessories such as fob scanners and locks will protect unauthorised persons from accessing the contents of the fridge, freezer or cold room. A display is not a standard feature in all units but can be incredibly beneficial. Displays can be used for viewing live data, reporting features and adjusting settings, for regulatory compliance as well as to ensure product integrity. Units with alarms are also highly beneficial so that, for example, if a door is left open- the problem can be rectified.
Withnell Sensors are temperature and humidity specialists, as an independent company we offer impartial advice on a range of application requirements. We have partnered with some of the world’s leading brands to bring you product and service solutions. Speak to one of engineers today for help and support.