topics · updated 2026-09-25
Cooling Technologies Overview
confidence: high volatility: cold verified: 2026-09-25fresh
The organizing map of cooling technologies in this wiki, sorted by what drives the heat pump — low-grade heat, electric work, sunlight, radiant emission, or the ground. The through-line is a bias toward heat-driven and passive cooling that runs on waste heat, sunlight, or the cold sky. Points to the deep article for every technology, working material, build guide, and thesis in the knowledge base.
The map of cooling technologies compiled in this wiki, organized by how the heat actually gets moved. The through-line is a bias toward heat-driven and passive cooling — systems that run on waste heat, sunlight, or the cold sky rather than on grid electricity through a compressor. This page is a map, not a data table: every row points at the article that carries the numbers and the sources. The side-by-side figures live in the Master Comparison; new readers should start at Getting Started.
The organizing question: what drives the pump?
Every cooling system moves heat from cold to hot, against the gradient, so something must drive it. What drives it is the cleanest way to tell these technologies apart:
| Driven by… | Technology | Page |
|---|---|---|
| Low-grade heat (waste/solar) | Adsorption — solid sorbent + water; cold from 60–95 °C heat (feasible from ~50 °C); thermal COP ~0.3–0.7, electrical COP very high | [[topics/adsorption-cooling |
| Low-grade heat (waste/solar) | Absorption — liquid sorbent (LiBr/water, ammonia/water); single-effect COP ~0.7, double-effect ~1.2–1.4; the more mature cousin with a practical floor near 90 °C | [[topics/absorption-cooling |
| Electric work (compressor) | Vapor compression — the refrigerant-cycle baseline everything is measured against; electrical COP 3–5, 60–80 % of Carnot at best | [[topics/vapor-compression-cooling |
| Sunlight → heat | Solar thermal — flat-plate, honeycomb, CPC and concentrating collectors that supply the drive heat; collectors are only ~20 % of installed cost | [[topics/solar-thermal |
| Sunlight → electrons | PV + heat pump — the route that now usually beats solar-thermal sorption on cost and simplicity; thermal keeps the free-heat / steady-load niche | [[topics/solar-cooling-pv-vs-thermal |
| Radiant emission to the sky | Radiative / black-body surfaces — passive heat rejection (BaSO₄ paint ~117 W/m²) and the inverse problem of near-perfect solar absorption | [[topics/radiative-cooling |
| The ground as heat sink | Geothermal / ground-source — stable earth temperature for heat rejection; the condenser partner that fights hot-day derating | [[topics/geothermal |
| Hot rock as heat source | Enhanced geothermal (EGS) — 175–200 °C brine for 24/7 ORC power; a potential but unrealized drive-heat source for chillers | [[topics/enhanced-geothermal-systems |
| Electric work (alt. cycles) | Heat pumps — two-way machines, including water (R718) turbo/ejector and solid-state frontiers | [[topics/heat-pumps |
| Field on a solid (no refrigerant) | Solid-state / caloric — magneto-, electro-, elasto- and barocaloric plus ionocaloric and thermoelectric; only thermoelectric ships | [[topics/solid-state-cooling |
| Form and mass (no machine) | Passive geometry — dome reverse-chimney effect, windcatchers, courtyards, thermal mass, termite-inspired buildings | [[topics/dome-cooling |
★ = the keystone for the 601 Delaware application — waste-heat adsorption chilling.
Working materials and machine internals
The heat-driven cycles are only as good as the sorbent and the bed it sits in.
| Layer | What it covers | Page |
|---|---|---|
| Zeolite | Aluminosilicate families, the 150–250 °C regeneration drawback, and the aluminophosphate pivot (EMM-8: COP 0.85 at 63 °C) | [[references/zeolite |
| Composite salt sorbents | Salt-in-matrix / SWS materials: 3–5× the uptake of silica gel, bounded by deliquescence, leakage and corrosion | [[references/composite-salt-sorbents |
| Adsorbent bed engineering | Coatings, conductive additives, metal foam, 3D-printed TPMS lattices, and the evaporator that co-limits the machine | [[topics/adsorbent-bed-engineering |
| Commercial chillers | Who sells adsorption chillers, their specs, the ~$215 M market, field deployments, and the 2025–26 third-generation shift | [[topics/commercial-adsorption-chillers |
| Adsorption vs absorption | The surface-vs-bulk distinction the two heat-driven families rest on | [[concepts/adsorption-vs-absorption |
Supporting threads
| Theme | What it covers | Page |
|---|---|---|
| Carbon Dioxide (R744) | CO₂ as a natural working fluid — transcritical CCHP, and the activated-carbon/CO₂ adsorption pair | [[topics/carbon-dioxide-r744 |
| Desiccant & free cooling | Air-side economization; desiccant handling of the latent load before any machine runs | [[topics/desiccant-and-free-cooling |
| Heat battery | High-temperature thermal storage — the storage counterpart that firms up intermittent drive heat | [[topics/heat-battery-thermal-storage |
| Hydronics | Hot/chilled-water distribution — the source-agnostic fabric connecting every source to the space; radiant ceiling emitters | [[topics/hydronics |
| Envelope & glazing | Load reduction first — SIPs, aircrete, double-skin façades, UV-transmitting acrylic, PCM roofs (resist / manage / transmit / store) | [[topics/envelope-and-glazing |
| Translucent PCM glazing | Which phase-change materials stay see-through in a window, and the one mature product | [[topics/translucent-pcm-glazing |
| Thermophotovoltaics | Heat → electricity by black-body light; the inverse of cooling on the same surface physics | [[concepts/thermophotovoltaics |
| Kleptothermy | The biological “joule heist” — harvesting an existing thermal stream; the KB’s namesake | [[concepts/kleptothermy |
Build guides and theses
| Kind | Page | One-line verdict |
|---|---|---|
| Build guide | [[references/diy-adsorption-chiller | Building a DIY Adsorption Chiller]] |
| Build guide | [[references/diy-pcm-encapsulation | DIY PCM Encapsulation]] |
| Concept | [[concepts/geometric-blackness | Geometric Blackness]] |
| Concept | [[concepts/topology-optimized-cooling-geometry | Topology-Optimized Cooling Geometry]] |
| Thesis | [[theses/fractal-hierarchical-bed-geometry | Hierarchical bed geometry → SCP]] |
| Thesis | [[theses/geometric-blackness-solar-adsorption-bed-face | Geometric blackness on a solar bed face]] |
Sources
This map is compiled from the wiki’s own articles, whose provenance chains run to individual raw files. The one raw source it cites directly is the hothothot Zotero group registry → Joule Heist → Topics cooling subcollections (150 references across 12 themes), which defined the original theme list: Zotero cooling source registry.
See Also
- Getting Started — new to this wiki? Reading paths and how it’s organized
- Master Comparison — the side-by-side table this map points at (COP, SCP, drive temp, maturity, best fit)
- Adsorption Cooling — the keystone heat-driven cycle
- Performance & Numbers — the quantitative envelope of adsorption cooling
- Limitations & Mitigations — why COP is low and what recovers it
- Absorption Cooling — the liquid-sorbent, higher-COP cousin
- Adsorption vs Absorption — the surface-vs-bulk distinction the two families rest on
- Vapor Compression — the electric baseline
- Solar Thermal — the collectors that supply drive heat
- Solar Adsorption Cooling — sun-driven adsorption from ice makers to two-bed chillers
- Solar Cooling: PV vs Thermal — is solar-thermal sorption still the right call vs PV + heat pump?
- PV Array Electrical Output — max voltage/current of PV arrays, supporting PV-driven cooling
- Radiative & Black-Body Cooling — heat rejection to the sky and near-perfect solar absorption
- Geothermal — the earth as heat-rejection sink
- Enhanced Geothermal Systems — deep hot rock as firm power; the hot-source end of the geothermal spectrum
- Geothermal-Driven Sorption Cooling — when geothermal heat should drive a chiller rather than a turbine
- Heat Pumps — two-way machines and the R718 / solid-state frontiers
- Solid-State & Caloric Cooling — refrigeration without a compressor
- Alternative Cooling Technologies — the not-in-kind scorecard
- Dome Cooling — passive cooling from curved form
- Vernacular & Biomimetic Passive Cooling — the pre-mechanical record with numbers
- Zeolite — adsorbent families and the low-regeneration pivot
- Composite Salt Sorbents — salt-in-matrix materials
- Adsorbent Bed Engineering — bed geometry, coatings and TPMS
- Commercial Adsorption Chillers — what you can buy today
- CO₂ (R744) — the natural working fluid
- Desiccant & Free Cooling — latent load and economization first
- Heat Battery — thermal storage that decouples heat from time
- Hydronics — water as the distribution fabric
- Envelope & Glazing — cutting the load before the machine
- Translucent PCM Glazing — latent-heat storage at the window
- Building a DIY Adsorption Chiller — the build guide
- DIY PCM Encapsulation — containers, sealing and failure modes
- Kleptothermy — the biological “joule heist”, the KB’s namesake
- Geometric Blackness — shape-based light trapping for coating-free absorbers
- Topology-Optimized Cooling Geometry — letting an optimizer grow cooling forms
- Thermophotovoltaics — heat to electricity by light; the inverse of cooling
- Thesis — verdict: partially supported
- Thesis — verdict: contradicted
- README — what this wiki is and how it relates to 601 Delaware
- 601 Delaware — Cooling Strategy — the building-applied summary