Yet, these spaces must still handle enormous heat loads – from both lighting and the millions of visitors they attract – while keeping priceless artworks safe with stable temperature and humidity year-round. This tension between preservation and performance demands a creative solution.

Paris’s underground cooling system

The Louvre’s answer lies beneath the city. Instead of traditional HVAC, it is connected to Paris’s district cooling network – a 52 km underground system that serves over 500 buildings, from opera houses to government offices. Here’s how it works:

• Production plant – Water from the Seine is cooled to 1–5 °C, sometimes using free cooling when conditions allow.

• Distribution network – Chilled water circulates through an underground double-pipe system, supplying buildings and returning reheated water.

• Delivery stations – Each building, including the Louvre, has a compact substation with heat exchangers that transfer cold energy into the building’s internal network.

• Remote monitoring – The entire system is controlled 24/7 for reliability.

This arrangement delivers museum-grade cooling without visible equipment, while cutting CO₂ emissions by up to 20% compared to standalone air conditioning.

Maintenance: the invisible backbone

Even the most ingenious system cannot be left unchecked. The Louvre’s cooling relies on ongoing partnership between operators, system builders, and equipment suppliers. Standardised delivery stations, continuous monitoring, and proactive maintenance are what keep the system stable. Without this vigilance, small faults – like heat exchanger fouling or pipe leaks – could compromise the delicate climate balance that preserves the art.

The lesson for complex spaces

The Louvre demonstrates that when traditional HVAC isn’t possible, engineers can turn constraints into opportunities. By looking beyond conventional solutions and prioritising long-term maintenance, even the most restrictive environments can be kept comfortable, efficient, and safe. At Inventive Air, we thrive on this kind of out-of-the-box thinking – finding smart, workable solutions to meet customers’ needs.