Drum volume
The internal volume of the dryer drum.
A
larger drum can accommodate more laundry, but there is no rigid dependence here: models with the same volume may differ in maximum load. It is because to process a large mass of laundry, one need not only a capacious drum but also an engine of appropriate power. At the same time, in a larger drum, the same mass of laundry will dry more efficiently than in a small one, because laundry will be more freely distributed over the drum, crumpled less, and warm air will better penetrate the folds of the fabric. As a result, for the same drum volume, a model with a smaller load will be more efficient and performant than a model with a larger load. On the other hand, a volumetric drum takes up more space and the dimensions of the dryer are largely determined by the dimensions of the drum.
Drain into sewer
This option allows you to automate the process of draining the condensate collection tank (respectively, it is relevant only for dryers with a condensation principle of operation). At the end of the drying process, the condensate accumulated in the tank is automatically drained into the sewer. To do this, a pump and a hose are provided in
a dryer with a drain into the sewer. The function of draining into the sewer allows you to significantly simplify the operation of the dryer, while in models without this option, the user must drain the condensate tank manually. Of course, manual emptying does not require much effort because the average condensate collection tank has a volume of about 5 litres, but still not very convenient.
Drying class
Drying class describes the overall drying efficiency that the machine provides. It is denoted by a Latin letter, where A is the best efficiency, and further in decreasing order (
drying class B is inferior to
class A, but exceeds
class C). Naturally, higher efficiency machines cost more (ceteris paribus).
Door opening
The direction in which the door of the dryer opens.
Most users are right-handed, so from this point of view, the best option is
leftward opening — the free space for loading and unloading laundry is just under the right hand. However, specifically in dryers, the
rightward opening is noticeably more common. It is because such units usually complement washing machines and are most often installed side by side. And in most washers, the door opens just to the left (again, based on convenience for right-handed people). Therefore, it is most convenient to place the dryer on the right and equip it with a hatch that opens to the right — this will allow you to overload the laundry from washer to dryer with minimal effort and time. And vice versa, if the door in the washing machine opens to the right, then it is better to choose a dryer with a leftward opening and install it on the left.
Sometimes both machines are installed as a column — a dryer on top of a washing machine. In such cases, the hatches of both machines should open in one direction — this is more convenient both from the point of view of ergonomics and purely psychologically. Moreover, if the "column” adjoins the wall sideways, then the opening should also occur towards the wall; otherwise, the laundry will have to be loaded and unloaded through the space between the open hatch and the wall, which can be very inconvenient.
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Note that in some dryers both opening options are claimed. It usually means that the door has a reversible mount, and the direction of opening can be chosen at your discretion. However, this feature does not hurt to clarify before buying.