The new Webasto Polar Cab TS engine-off cabin cooling system provides on-demand cooling during downtime, resulting in fuel savings, reduced idle time, increased productivity, and operator safety and comfort.


Polar Cab TS engine-off cooling features a patented storage core with a series of aluminum micro-channels that route R-134a liquid refrigerant around a graphite honeycomb substrate that’s impregnated with water. The substrate is capable of storing cold energy at an extremely high efficiency, according to Webasto. This cold energy is transferred to the cab for on-demand cooling via an air handler, which measures 19.3 x 6.3 x 18.5 in (490 x 160 x 470 mm) and weighs 18 lb (8 kg).


The core and charge unit is 26.0 in (660 mm) wide, 26.4 in (670 mm) deep, and 28.4 in (720 mm) tall, and weighs 330 lb (150 kg).


The system has a cooling capacity of 1.3 kW (4450 BTU/h). The Polar Cab TS does not require any additional batteries and consumes very little power, according to Webasto. Technical specifications show that for engine-on charging, charge amp draw is 50 Amp nominal (45 Amp compressor and 5 Amp condenser). Engine-off discharging is 7 Amp nominal (5 Amp blower and 2 Amp coolant pump).


The cooling system can be installed at the dealership on new equipment as well as on existing equipment.

The system can be fully recharged within 3 h. According to a company spokesperson, the TS 24-V system holds cold stored energy with static discharge rate of 10% per 24-h period at 130°F ambient temperature. Field testing and climate chamber test have substantiated 90 min of engine-off cooling at 110°F ambient temperature, under full sun load.


Webasto’s Polar Cab TS engine-off cabin cooling system features a patented storage core with a series of aluminum micro-channels that route liquid refrigerant around a graphite honeycomb substrate impregnated with water.

“Engineering challenges included finding the right balance between performance and size/volume of the system,” the spokesperson shared with Off-Highway Engineering. “Webasto engineers committed to provide a system that is adaptable and easy to install on a variety of machines. Due diligence was exercised by the team to ensure that the product performs in the severe off-highway environment.”


Polar Cab TS has been in development for two years including extensive field testing with customers under extreme climactic conditions: high humidity, high heat, dust, and dirt. Testing has been performed on machines in the southern regions of California, Arizona, Texas, and Mississippi as well as in North Carolina and Michigan. The technology has been used in the on-highway market for 10+ years, according to Webasto.


“Designing products with operator safety and comfort in mind is a big part of our business plan at Webasto,” said Dr. Rolf Haag, Webasto Thermo & Comfort North America President and CEO. “Webasto products provide operators an opportunity to reduce machine hours, scale down fuel costs, lease payments, and lower annual maintenance costs.”


Webasto offers Polar Cab TS as an aftermarket kit, which includes the thermo storage core, electrical compressor (24-V), condenser with fan (24-V), air handler, wire harness, and miscellaneous hardware needed for installation. The system can be installed at the dealership on new equipment as well as on existing equipment.

Source: sae.org