Doll air-heaters type series PWW (pump hot-water) have been developed for heating and aeration of greenhouses. They are designated for hanging attachment or as floor-mounted appliances and for distribution of warm air in houses via clime-measured hot-air tubes or aeration-tubes.
Doll PWW devices are standardly manufactured in a system power range from 15 up 400 KW heating power. The devices are equipped with a heat register component with a hot-water-pump register, made of copper-aluminium in a steel zinc-coated completion or made of stainless-steel. PWW devices are mounted, depending on the system-power on a self-supporting base frame made of special aluminium profiles or zinc-coated, blue chromated steel-profile tubes, each with corner connectors.
The casing is respectively equipped on requirement with single-walled or double-walled insulated casing plates which are screwed-in air-proof. On request the devices are equipped with an hanging attachment appliance. The ventilators are standardly equipped with double sided priming radial-ventilators in zinc-coated completion. Ventilator and motor are mounted on a swinging frame. The motor is additionally mounted on a motor-slide for unproblematic an unproblematic stretching of mechanical belts. For hot-air tube operation the devices are obtainable with a smooth-start-up device for ventilation.