Tiered or winged?
Tiered airers use vertical space and suit larger mixed loads. Winged airers are lower, often simpler to load and useful for longer garments, but take up more floor area.
Drying space and load capacity
Manufacturers commonly quote rail length in metres and a maximum wet-load weight. Rail arrangement matters too: closely spaced bars can make bulky items awkward.
Wattage and controls
Wattage helps estimate hourly cost. A timer is useful because it can prevent the airer staying on after clothes are dry.
Covers and ventilation
A fitted cover can retain warmth, but the moisture still has to go somewhere. Ventilate the room and follow the product instructions.
Storage and safety
Measure the open footprint and folded depth. Keep the airer stable, do not overload it and never substitute bedding or plastic sheeting for a purpose-made cover.