Comparison Polaris PFD 2705 vs Gemlux GL-IR500

– Vertical fruit dryer. Vertical models of dryers involve loading vegetables and fruits on perforated trays, which are placed one above the other in several tiers. The heating element and the fan in their design are at the bottom, and hot air is blown from the bottom up. As a result, products on the lower shelves dry much faster than those on the upper levels. During the drying process, it is often necessary to swap the upper and lower trays. In many instances of vertical dryers, this disadvantage is eliminated due to the successful shape of the pallets.

— Dehydrator (horizontal dryer). Horizontal dehydrators are better than vertical ones. Often they are made in the image and likeness of small ovens with pull-out trays to place products. Hot air in the oven of the horizontal type dryers is blown by a fan, which is installed on the rear wall perpendicular to the trays with vegetables and fruits. Horizontal airflow ensures uniform drying of products at all levels. However, the pricing policy for devices of this order is more “biting”.

Horizontal dimensions of one dryer tray.

For round models, this paragraph usually indicates the diameter (for example, “Ø250”), for other cases — the length and width. Anyway, the information about the size allows you to estimate the total area and, accordingly, the capacity of the device. At the same time, note that a larger size affects the dimensions and weight of the structure, and also requires more heating power (ceteris paribus).

The size of one tray of the dryer in height. In models where, instead of separate trays, a common working chamber with removable shelves is provided, the distance between two adjacent shelves is indicated.

This size primarily determines the thickness of individual pieces of vegetables, fruits, etc., which can be placed in the device. At the same time, note that the contents should not fill the tray tightly — there should be at least a couple of millimetres of space between the products and the “ceiling”. Also note that in some models, two height values can be indicated in this paragraph — for example, “15 — 25 mm”. This means that the size of the trays can be changed, adjusting them to the specifics of the situation; usually it is a choice between two standard heights (in our example — 15 mm and 25 mm).

Rated power consumed by the dryer during operation.

This parameter is usually selected by manufacturers depending on the volume of the dryer: the larger the device, the more power is needed to effectively heat the working chamber. At the same time, models with the same volume may differ in power consumption. In such cases, it is worth considering that a higher power reduces the heating time, but affects the price of the device.

The temperature range that the dryer can provide in the working chamber.

The simplest models provide only one operating temperature option, usually from 50 °C to 60 °C. More advanced devices equipped with thermostats (see above) and can have a wide range of adjustment — this is very useful, because different temperature regimes are recommended for different products. To assess the general capabilities of a particular dryer, you can use the following table of temperatures recommended for drying:

— 35...40 °C — plant stems, greens;
— 40...45 °C — bread;
— 38...42 °C (in some cases up to 45 °C) — yoghurt;
— 50...55 °C — vegetables;
— 55...60 °C — fruits;
— 65...75 °C — meat, fish.

We emphasize that these are the most general, conditional data. The specific temperature may differ from the recommended one — depending on the thickness of the slices, the specific type of food, the desired result, etc. Detailed recommendations on this matter can be found in special sources.

The location of the heating element (fan with heater) installed in the food dehydrator. This element can be installed at thebottom, top or behind, here are the features of each of the options:

— Bottom. The classic and most common arrangement for heaters in food dehydrators is located at the bottom. This design choice offers two main advantages. Firstly, warm air is evenly distributed throughout the dryer's volume as it rises from the bottom. Secondly, these devices have compact dimensions in terms of width and depth, which are mainly determined by the size of the trays. This allows for more flexibility in terms of placement options. However, a potential drawback of the lower heater placement is the possibility of contamination, which can result in unpleasant odors. In such cases, disassembling and thoroughly cleaning the dryer may be required. Nonetheless, most manufacturers take steps to address this issue, making it less of a critical concern.

— Top. The safest location for the heater in a food dehydrator is considered to be at the top, as it minimizes the risk of moisture from the dried products coming into contact with the heater. Similar to the previously mentioned design, the width and depth of the food dehydrator do not exceed the size of the trays. However, dehydrators with a top-mounted heater may not provide uniform heating. Warm air tends t...o accumulate in the upper part of the device, resulting in the upper trays being heated more than the lower ones. In theory, this can be advantageous for drying products that require different temperature conditions, as higher-temperature items can be placed higher in the dehydrator. However, in practice, it is challenging to account for the actual temperature difference accurately. This aspect becomes a clear disadvantage when drying uniform ingredients, as it requires periodic rearrangement of the trays to achieve even processing. As a result, there are fewer models with a top-mounted heater available nowadays.

— Behind. Food dehydrators in this category have a layout that differs from the previously described options. They resemble ovens with baking sheets, where a common working chamber is used instead of separate trays stacked on top of each other. Inside the chamber, lattice shelves are fixed with special slots or protrusions on the walls. The heater is located at the back of the "oven". This design is considered highly advanced, as it allows for easy removal and placement of individual trays without disturbing the others. It also provides very uniform heating and minimizes the mixing of odors between different levels. Moreover, the lattice shelves can be rearranged to increase the height of specific "trays". However, the drawbacks of models with a rear heater include their bulkiness and higher cost. As a result, this layout option is primarily used in semi-professional and higher-level food dehydrators.

A special device that turns off the heating after a predetermined time.

The presence of a timer greatly simplifies the use of the device: instead of monitoring the duration of the process and manually turning off the heater, it is enough to set the desired turn-off time in the settings. In addition, this function reduces the risk of forgetting about drying products and “overexposing” them in the dryer: this can only happen if the timer was initially set for too long.

Note that the type of timer directly depends on the type of control (see above); at the same time, mechanical timers are simple and inexpensive, but they have a rather noticeable error, and electronic ones are very accurate, but they cost accordingly more.

The material from which the complete trays of the dryer are made.

— Plastic. Inexpensive, but at the same time very practical material. In terms of strength and overall reliability, the plastic is inferior to metal, however, during normal use of the dryer, this difference is not noticeable. In addition, if such trays are made in the form of complete compartments, their walls can be made transparent so that you can observe the contents without interrupting the process and without knocking down the temperature regime. However the transparent walls gradually become cloudy due to the low resistance of plastic to scratches — however, it takes a lot of time for this moment to become a serious inconvenience. Thus, most modern dryers use plastic trays.

— Stainless steel. The main advantages of metal trays are strength and resistance to overheating. On the other hand, these advantages rarely turn out to be significant, and steel is more expensive than plastic. In addition, if metal trays are made in the form of separate compartments, they are opaque, and to check the condition of the products, you will have to open these compartments, lowering the temperature and disrupting the process. . For models with a rear fan (see above), this point is not relevant — they usually have a transparent door; however, such devices are not cheap. Thus, this tray material is rare nowadays — mainly among advanced dryers.