Thanks to their construction and equipping them with big wheels, the DHB dehumidifiers are dedicated especially to construction works and to dehumidifying water treatment plants. Most construction works require large amounts of water which is then left in walls, floors, and ceilings, and that should be removed in order to continue the construction. Later, during finishing works, it is again beneficial to accelerate the dehumidification process of gypsum walls, plasterwork, drying paint etc. In such situation, airing of rooms is chosen in periods other than winter, and ventilation with heating during winter. However, both of these methods are insufficient, and sometimes they have no effects at all. In spring and autumn, air outside is cold and humid. And the ventilation plus heating method used in winter is cost-consuming and not effective. In case of dehumidification of a building can be seen when dehumidifying equipment is used. They liquefy humid from the air, and allow continuous absorption of humidity from walls, ceilings and floors. The devices should be located in a closed area in order to limit access to the cold air outside. DHB and DHB-W dehumidifiers can operate in low temperatures from 10°C thanks to defrosting with hot gas, which makes work in non-heated rooms easier.