Polar WHT mobile water-to-air heaters are mainly used on construction sites with district heating network. The heaters have an incoming water connection with cam-lock coupler, 1" (AL). Upper connection (return) has cam-lock adapter, adjustable valve for circulated water and a bleed screw. The units also have an internal frost protector thermostat (set at +4°C) which stops the fan in case the air temperature gets too low. Incoming air filter protects the heat exchanger fins from dust. WHT heaters are equipped with wheels for movability. Heat is transferred to outblown air using a heat exchanger with copper pipes and aluminium fins. Heat exchanger is only suitable for hot water (not steam). WHT 250 is our latest model of movable water-to-air heaters. The massive 249 kW water coil and 20.000 m3/h air volume are usually sufficient for most heating needs. The fan sucks the air through the filter and water coil. As a new feature the WHT 250 introduces a rolling water coil - fan asssembly. The coil - fan assembly enables directing the air vertically if needed. Clicking the picture will open a picture of the unit in horizontal position. Despite the unit is fairly heavy it is pretty easy to move thanks to the big wheels and forklift holes.