District cooling, sized and costed before you commit to a plant.

District cooling is a shared chilled-water system that produces cooling at a central plant and distributes it through an insulated pipe network to many buildings, instead of each building running its own chillers. It is common on campuses, in dense downtown and mixed-use districts, and around cooling-heavy loads like data centers. Because a central plant serves the pooled, diversified load of many buildings, it usually needs less installed chiller capacity than the sum of standalone systems, and it can add thermal storage to shave the peak. Sympheny sizes that system against the district's real cooling load and prices it against decentralized cooling.

Decentralized cooling gives each building its own chillers, sized for that building's own peak. District cooling pools the load of many buildings onto one central plant and a shared chilled-water network. Because buildings rarely all peak at the same moment, the central plant can be smaller than the sum of the individual systems, and it can run more efficiently and host thermal storage. The trade-off is the cost and disruption of the network. Sympheny compares the two on the same life-cycle cost and carbon basis, on real hourly demand, so the central-versus-distributed decision is costed rather than assumed.

Cooling is peaky: a few hot hours set the demand charges and the chiller sizing for the whole year. Chilled-water or ice storage makes and stores cooling in the off-peak hours and discharges it during the peak, so the central plant can be smaller and the demand charge lower. The value depends on the hourly cooling profile and the tariff, which is why it has to be sized against the real load. Sympheny sizes the storage inside the same optimization that sizes the plant, and shows how much it shaves off the peak and the capacity charge before you commit.

Sympheny builds a GIS model of the district — the buildings, their hourly cooling and heating demand, and the on-site resources — then sizes the central plant, routes the chilled-water network and places thermal storage as one mixed-integer optimization. Chillers, heat recovery, free cooling and storage all enter as candidate technologies, and the shared system is compared against decentralized cooling on life-cycle cost and CO2. The outputs are deterministic and traceable, so an engineer or a reviewer can interrogate every number.

District cooling is the cooling side of a thermal energy network. A thermal energy network is a shared loop that moves heating and cooling between buildings, often at low or ambient temperature, with heat pumps and recovered heat. District cooling is the case where the dominant load on that loop is cooling. Sympheny models heating and cooling on the same network, so a cooling-led project is planned in the context of the whole thermal energy network rather than as a separate system. You can read more on the thermal energy networks pillar.

Usually three things: the cooling load and how dense and diverse it is across the district, the cost and disruption of building a chilled-water network, and the value of pooling the load and adding thermal storage to shave the peak demand charge. Resilience matters too where the cooling cannot go down, as around data centers. Sympheny puts all of these on the same cost and carbon basis, so the developer, university or utility can see whether a shared plant pencils out against decentralized cooling before the layout is fixed.