{
 "id": "6.07",
 "slug": "heat-reuse-and-district-heating-interfaces",
 "url": "/parts/facility-cooling-and-hvac/heat-reuse-and-district-heating-interfaces",
 "name": "Heat reuse & district heating interfaces",
 "qualifiers": null,
 "layer": {
  "id": 6,
  "name": "Facility cooling & HVAC"
 },
 "parent_id": null,
 "children": [],
 "summary": "Heat exchangers and interconnection equipment that export waste heat from a data center's cooling loop into a district heating network or other end use instead of rejecting it to atmosphere.",
 "description_md": "Taps the facility water loop (6.05) — typically its warmer, IT-heat-carrying side — and routes it through a heat exchanger, and where the reuse temperature needs boosting, a large heat pump, into a district heating network or process-heat customer, displacing some of the heat-rejection equipment (6.02) a site would otherwise need. Adoption is concentrated where district heating networks already exist and local economics or regulation favor it, so it remains a minority design choice rather than a default. Higher-temperature liquid-cooling loops in AI racks produce warmer reject water than legacy air-cooled facilities, which is exactly the direction that makes heat reuse more thermodynamically attractive, since a heat pump has less work to do raising an already-warm source to district-heating temperature. Investors should treat this as a niche but growing interconnection market tied to specific geographies with district heating infrastructure, not a broad-based demand driver across the layer.",
 "ai_delta": "Liquid-cooled AI racks run their facility loop hotter than legacy air-cooled halls, producing waste heat closer to the temperature district heating networks need and lowering the heat-pump work required to reuse it.",
 "bottleneck_status": null,
 "scale_tiers": [
  "hyperscale_building",
  "ai_campus",
  "gw_class"
 ],
 "density_modes": [
  "liquid",
  "hybrid"
 ],
 "scale_notes": "Presence depends on site-specific access to a district heating network or heat customer rather than on facility size alone; more thermodynamically attractive at ai_campus and gw_class sites running hotter liquid-cooled loops.",
 "flow": [
  "heat"
 ],
 "companies": [
  {
   "company_id": "alfa-laval",
   "name": "Alfa Laval",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "public",
   "ticker": "ALFA.ST",
   "product_note": null,
   "note": null,
   "source_url": null
  },
  {
   "company_id": "carrier",
   "name": "Carrier",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "public",
   "ticker": "CARR",
   "product_note": null,
   "note": null,
   "source_url": null
  },
  {
   "company_id": "fortum",
   "name": "Fortum",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "public",
   "ticker": "FORTUM.HE",
   "product_note": null,
   "note": null,
   "source_url": null
  },
  {
   "company_id": "man-energy-solutions",
   "name": "MAN Energy Solutions",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "subsidiary",
   "ticker": null,
   "product_note": null,
   "note": null,
   "source_url": null
  },
  {
   "company_id": "siemens-energy",
   "name": "Siemens Energy",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "public",
   "ticker": "ENR.DE",
   "product_note": null,
   "note": "large heat pumps",
   "source_url": null
  },
  {
   "company_id": "trane",
   "name": "Trane",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "public",
   "ticker": "TT",
   "product_note": null,
   "note": null,
   "source_url": null
  },
  {
   "company_id": "danfoss",
   "name": "Danfoss",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "private",
   "ticker": null,
   "product_note": null,
   "note": null,
   "source_url": null
  },
  {
   "company_id": "kelvion",
   "name": "Kelvion",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "private",
   "ticker": null,
   "product_note": null,
   "note": null,
   "source_url": null
  },
  {
   "company_id": "qarnot",
   "name": "Qarnot",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "private",
   "ticker": null,
   "product_note": null,
   "note": null,
   "source_url": null
  },
  {
   "company_id": "vattenfall",
   "name": "Vattenfall",
   "role": "manufacturer",
   "confidence": "inferred",
   "ownership_type": "state",
   "ticker": null,
   "product_note": null,
   "note": null,
   "source_url": null
  }
 ]
}