Although condensing dryer technology has been popular in Europe and Asia for many years, the ventless laundry concept here in North America has struggled to gain widespread appeal.
Americans were first introduced to ventless drying in the 1980s when European-made washer dryer combos began to appear on boats and recreational vehicles. These early ventless combos used an internal condensing system in which a narrow condensing chamber was attached to the outer washer drum. Due to their narrow dimensions and location adjacent to the warm drum, internal condensers were prone to lint and soap residue buildup, which over time resulted extended dry times.
Luckily, most new combination machines now use an external condenser, which is separated from the dryer drum and therefore offers much faster drying. In addition to washer dryer combinations, new stand-alone 220 volt ventless dryers use an entirely different heat-exchange system which works as a dehumidifier to dry clothing significantly faster. These new ventless dryers now offer dry times that rival standard vented dryers.
Despite these advances in condensing dryer technology, the following misconceptions still remain:
Early ventless dry systems from the 1980s took a long time to dry; in some cases over 2 ½ hours. Although newer condensing systems dry significantly faster, ventless dryers are still burdened with the reputation of slow dry times. 
Modern washer dryer combo systems now dry clothing in about 90 minutes and the new stand-alone condensing dryers usually take 45 – 60 minutes for a full load. Combo machines typically operate on 110 volt power and utilize a small drum, which translates into slightly longer dry time compared to stand-alone 220 volt ventless or vented dryers.
2. Ventless dryers release moisture back into the surrounding room
Condensing dryers use a closed-loop system that removes dampness from the air using a dehumidifying process which does not release heat, lint or moisture into the surrounding room. Stand-alone ventless dryers release a small amount of dry air back into a room as a result of a heat-exchange system which uses air to cool an internal radiator.
Ventless dryers now come in all sizes, from the smallest combo machine to a large stand-alone condensing system. Early combos typically found in boats and RVs were quite small compared to the expansive washers and dryers sold today. But technological advances have allowed ventless dryers to grow larger with time.
4. Ventless systems use more energy
Actually, the opposite is true - condensing systems use 50% - 70% less energy than standard vented dryers. Unlike vented dryers that continuously expel and reheat air, ventless closed-loop systems remove moisture and re-circulate warm dry air back into the dryer drum. The result is less stress on the dryer heating element and a more efficient way to dry clothing.
Another added benefit of condensing dryers relates to heating and air conditioning. In most parts of the world, a residence is heated in the winter by a furnace and cooled in the summer by an air conditioner. Vented dryers remove an average 200 cubic feet per minute of air from a surrounding room. That means that a HVAC system needs to work harder and use significantly more energy during vented dryer operation.
5. Ventless dryers don’t conform to building codes
The majority of ventless dryers on the market are UL or ETL approved, enabling them to meet building codes throughout the country. In addition to being approved under the International Building Code, many ventless models meet strict municipal codes that go above and beyond the ICB building requirements.
