uPods in Winter: Why It’s Warm Inside String Transport

Just imagine: it's -25 °C outside, the wind is blowing snow off the tracks, but inside the uPod, passengers can calmly take off their gloves, get out their smartphones, and ride in warmth and comfort. This is because most models of rail unmanned vehicles manufactured by UST Inc. are equipped with an autonomous climate control system with its own heating circuit, thermal insulation, and ventilation. For string rail string transport, winter is not a challenge, but rather a normal operating condition.

Why does a uPod need a thermal circuit?

String transport moves above the ground, at a height of tens of meters, and can be exposed to harsher weather and seasonal conditions. In winter, the air temperature is, of course, low, which increases the heat loss of the rolling stock.

Therefore, the uST complex's passenger electric vehicles are designed as closed capsules equipped with multi-layer thermal insulation, an air recirculation system, and electric heaters. This effectively turns each uPod into a mobile thermal circuit that retains heat in the same way as a modern energy-efficient house.

Focus on PTC heating elements

A PTC (positive temperature coefficient) is a semiconductor heating element whose electrical resistance increases as the temperature of the heater itself rises. The use of such devices for heating rolling stock in uST complexes is a conscious decision. These elements can be classified as smart, as they do not overheat but are capable of stabilizing the temperature automatically. This is an ideal solution for electric transport, where reliability and comfort are paramount.

In addition, to achieve an effective thermal circuit, virtually every uPod model has a lightweight composite shell, multi-layer sound and heat insulation, a controlled recirculation system that changes the ratio of fresh and heated air, and an electric heat generator. This set of solutions has allowed UST Inc. engineers to achieve high maintainability of the rolling stock with minimal energy consumption. 

Transport for regional routes

The company's engineers have developed the two-section uPod U4-220-T2 specifically for suburban transport. Its front and rear fairings house two climate control units with six high-voltage PTC heaters (450 VDC) with a total power of 9 kW for heat generation.

A special feature of this model is the built-in electric heating mat (“warm floor”). The floor and roof of the rolling stock in places where there are no frame beams are filled with closed-cell polyvinyl chloride foam. This uPod also features an adjustable recirculation system, where the air inside the cabin is mixed with the outside air, heated, and fed back into the cabin. Therefore, even if it is -25 °C outside, passengers remain comfortable standing on the heated floor, while warm air is directed simultaneously to the upper and lower parts of the cabin.

uPods for urban environments

The compact U4-210, U4-430, and U4-651 models are designed for short urban routes. The first uPod is equipped with two climate control units (in the traction module and tail fairing) with high-voltage RTC elements (500 VDC) with a total power of 5.6 kW. The model also features adjustable recirculation, a fairing insulated with 10 mm open-cell polyurethane foam, and a ceiling and floor insulated with closed-cell PVC.

For reference, open-cell fibrous materials primarily provide sound absorption, while their thermal insulation properties are secondary. In contrast, closed-cell materials are mainly used for thermal insulation, although they also offer a certain degree of noise reduction.

The U4-430 is equipped with a single 2.8 kW heater and has no recirculation. However, its climate control system is simple and reliable. Fresh outside air is heated and supplied to the upper part of the cabin through flexible air ducts. Excess air is first directed into the space beneath the front and rear fairings and then discharged to the outside.

The uPod U4-651 has a single 0.7 kW heater built directly into the door: a built-in fan helps to distribute the warm air flows (this element is present in all uPods). Such solutions have made it possible to simplify the technical design of rail unmanned vehicles while achieving maximum energy efficiency.

Transportation that is not afraid of bad weather

The engineers at Unitsky String Technologies Inc. face an ambitious task: to create transport that is not only efficient and inexpensive, but also comfortable for passengers. Proven and repeatedly tested technical solutions allow uST complexes to be adapted to any climate, including severe frosts. The smart, balanced climate control system, which is installed in almost every uPod model, makes the trip pleasant regardless of the temperature outside.