Electric dryers that use 110 volts work similarly to 220-volt dryers, but they tend to be significantly smaller. Electrical resistance is used to generate heat, and air blows this heat onto the clothing in the dryer.
Most dryers use 220-volt connections to generate sufficient heat and spin the large drum. While 110-volt outlets can supply enough power, the dryers need to draw far more amperage than a 110-volt outlet can provide. Consequently, most 110-volt dryers are significantly smaller than their higher-voltage counterparts. Because of their smaller size, 110-volt dryers are often used in apartments and other small spaces, and many are part of combination washer-and-dryer units designed to save space.
Smaller 110-volt dryers sometimes use ventless technology. Dryers evaporate water trapped in clothing, but they must remove this moisture from the system. Traditional 220-volt dryers simply vent air outside, while ventless models create a cool area that converts water vapor into a liquid form, so it can be drained out of the system. These models don't vent away hot air, so less electricity is needed to create a sufficiently warm environment. Other systems even use heat pump technology to provide better efficiency, although these models typically cost significantly more, as of 2015.