PCM passive shelters keep internal temperatures under control in extreme climates by harnessing a Phase Change Material: no HVAC, no water tanks, no moving parts. Fully prefabricated, monolithic and delivered plug-and-play, they protect electrical equipment in remote and desert installations for more than 20 years.
Overview
Developed by Alex Sistemi and protected by patent, the PCM passive shelter replaces the conventional water-tank passive system with profiles filled with Phase Change Material. During the day the PCM absorbs the heat generated inside the shelter and the heat coming from solar radiation as it melts; at night, as the outside temperature falls, finned pipes on the roof drive a natural convective cycle that carries the stored heat outward and the PCM solidifies, ready for the next day. There is no active cooling unit to power, service or fail, and no water inside the shelter that could leak onto the equipment.
How it works
- Day: the PCM absorbs the internal and solar heat
- Melt: the material changes phase and stores the energy
- Night: the roof pipes convect the heat outward
- Reset: the PCM solidifies for the next cycle
The design assumes a mean day temperature of 50 °C and a mean night temperature of 25 °C in the hottest period, with peaks of 55 °C. The passive system keeps the internal temperature typically about 5 to 6 °C above the night temperature, with a daily excursion of roughly 25 °C: it is a natural cycle, not a set point.
Main components
PCM modules replacing water tanks; custom-engineered metal structure; roof convective finned pipes; sealed monolithic body, leak-proof around the electrical equipment; integrated electrical system with distribution board, cable trays and Ex-rated battery room.
Dimensioning
The passive system is sized with proprietary software developed by Alex Sistemi. From the site location and the maximum day and night temperatures, the software analyses the temperature database of the last 50 years, adds the internal heat dissipation of the equipment and battery rooms and the heat entering from solar radiation, and returns the exact quantity of PCM and the linear metres of finned pipes required. The balance matters: over-sizing degrades performance as much as under-sizing.
Configuration and applications
Shelters are fully prefabricated, complete with wiring, panels and equipment, and tested before delivery. They are supplied as a single monolithic piece, with no on-site assembly of modules, lifted by ISO corners or lifting lugs, and are designed for easy modular enlargement as the site grows. Typical applications are equipment shelters for Oil & Gas facilities, gas pipelines, remote and unmanned sites and desert installations. The build includes 100 mm insulation, extensive use of aluminium, a high-durability painting cycle and doors with double neoprene seals, three heavy-duty stainless steel hinges and three lock points, with the handle and keyhole protected from sand and dust.
Testing and compliance
Every shelter undergoes an in-house thermal test in the climatic chamber, simulating the day and night cycle for up to four days with an automatic report, a rain test up to 150 mm/h, PCM system functional and thermal dissipation tests and a final acceptance test, in addition to dimensional, coating, electrical, functional, load and drop, pressure, leak and weld inspections. Design is validated by 3D modelling and seismic analysis. Fabrication is carried out under ISO 9001:2015, ISO 3834-2:2021, EN 1090, CSA W47.1, A660 Canadian Standard, EN 13084-7:2012 and ISO 45001:2018. See our quality and certifications page.
PCM passive shelters are developed by Alex Sistemi within the Group’s 100% in-house production cycle. Contact us with your site temperatures and equipment heat loads.
