The Four Loops

One building. Four loops.
Every one provable.

An Intelligent Harvest greenhouse runs four closed loops — heat, water, roof, and soil. Below is each loop’s official schematic, the verified language for what it does, and the math underneath it — with an honest line, every time, between what’s measured and what’s still a design target for a site we haven’t built yet. Worked examples use real constants and public U.S. climate data — no single site assumed.

Measured / real constant. Public climate data, physical constants, equipment specs, peer-reviewed ranges. You can check every one.
Design target. A magnitude that depends on a specific built site — load, area, throughput. Honest until there’s a site to measure.
01 — The Heat Loop

Captured, not vented.

“Server heat that would be vented is captured in a sealed loop and carried to the greenhouse — then returns, cooled, to warm again.”
Verified language · IH Heat Loop schematic
HOW IT MOVES  ·  01 HEAT DATA CENTERservers · rejected heat HEAT EXCHANGERsealed · loops never mix BUFFER TANKholds warmth steady GREENHOUSEfour zones, warmed in turn CHILL LOOPreturns cool to the hall Hot supply Greening through the zones Chilled return Powers the cloud. Feeds the town. Illustrative — schematic, not to scale
The Heat Loop — data center → plate heat exchanger (the two loops never mix) → four greenhouse zones → cooled return. Animated schematic, official build-hub document.

A data center’s cooling problem is the greenhouse’s heating supply. Warm coolant leaving the servers crosses a plate heat exchanger — a stack of thin steel plates where the data-center loop and the greenhouse loop trade heat but never share a drop of water. The greenhouse side carries that warmth to the four zones and returns cooler, ready for the next load. Two fluids, sealed and separate, end to end.

The proof
Law 1 — Conservation of energy

A server is, thermodynamically, a heater that happens to compute. Essentially all the electrical power it draws leaves as heat — so a hall’s heat output is approximately its electrical load. The warmth is already there, already paid for, whether or not anyone catches it.

electrical power in  ≈  heat power out
Law 2 — What the loop can carry

How much heat a flowing loop moves is fixed physics: mass flow, times the heat capacity of water, times the temperature it gains across the exchanger.

Q  =  · cp · ΔT
Real constant: cp of water = 4.186 kJ/kg·°C (= 1 BTU/lb·°F).
So each 1 kg/s of loop water carries 4.186 kW for every 1 °C of ΔT.
at a 6 °C supply/return gap →  1 kg/s ≈ 25 kW  ·  10 kg/s ≈ 251 kW
Matching any given hall is then just choosing flow and ΔT. The physics doesn’t cap it — the site sizes it.
What it means for your townEstimate · illustrative †
3,000MWh of rejected heat reused / year
300,000lbs of food grown / year
900people’s fruit & veg / day

The heat the campus would throw away becomes the harvest the town eats. A Small facility supports about one flagship greenhouse module of reuse — and it’s a sliver of what the campus rejects; the rest of its heat is unchanged.

Illustrative design targets, scaled from the flagship anchor (300,000 lb / 3,000 MWh per module) by the same model the homepage calculator uses. Real and unconditional: energy conservation, cp = 4.186 kJ/kg·°C. Put on the record once metered: delivered heat and crop output.

Built by — Gladiator

The insulated supply-and-return main runs underground and trenchless between the hall and the greenhouse — bored in by horizontal directional drilling rather than cut across the site. A Gladiator G30 rig (≈ 29,000 lb of pullback, 147 hp) pulls the carrier pipe through undisturbed ground. That’s Dallas Rush’s world: moving energy and utilities under a site without tearing it open.

Measured / real
  • Energy conservation — electricity in ≈ heat out
  • Heat capacity of water, cp = 4.186 kJ/kg·°C
  • Q = ṁ·cp·ΔT — the carry relationship
  • Gladiator G30 rig spec (≈ 29,000 lb pullback)
Design target
  • The hall’s actual IT load (MW)
  • The greenhouse’s heat demand
  • Loop flow rate and chosen ΔT
  • Pipe run length and bore depth
02 — The Water Loop

The roof feeds the room.

“Rain is captured off the sawtooth roof, the dirty first flush is diverted away, and clean water is stored, filtered, and returned to the four zones below — all one building.”
Verified language · IH Water Loop schematic
HOW IT MOVES  ·  02 WATERINTELLIGENTHARVESTCaptured rainwaterFirst flush → stormwaterSAWTOOTH ROOFFOUR ZONES · watered from above↩ returned to the zonesFIRST-FLUSHDIVERTERdirty first water rejectedstormwater (separate)COVERED RESERVOIRsealed store · loops never touch itFILTER · UV The Water LoopRain is captured off the sawtooth roof, the dirty first flush is diverted away, and clean wateris stored, filtered, and returned to the four zones below — all one building.Powers the cloud. Feeds the town.Illustrative — schematic, not to scale
The Water Loop — sawtooth roof → first-flush diverter → covered reservoir (sealed) → filter + UV → four zones. Stormwater stays separate. Animated schematic, official build-hub document.

The same sawtooth roof that lets light in catches the rain that falls on it. The first flush — the dirty opening of a storm that rinses dust and debris off the roof — is diverted to stormwater and never enters the clean system. What’s left runs to a covered reservoir, is filtered and UV-treated, and waters the four zones from above. The reservoir is sealed; the loops never touch the stormwater.

The proof — capture math, real numbers
The capture identity

Harvested volume is just roof area, times how much rain fell, times how much of it you actually collect.

V  =  A · P · C
Real constant: 1 inch of rain on 1 ft² = 0.623 gal. → on 1,000 ft² of roof, 1 inch = 623 gal.
Collection coefficient C ≈ 0.85 for a smooth roof after first-flush diversion.
What that yields, per 1,000 ft² of roof, per year

Using each region’s NOAA / NCEI 1991–2020 rainfall normal (real, public), at C = 0.85:

RegionNormal rainCapture / 1,000 ft²·yr
Northeast≈ 44 in≈ 23,300 gal
Mid-Atlantic / Coastal≈ 46 in≈ 24,400 gal
Southeast≈ 52 in≈ 27,500 gal
Midwest≈ 39 in≈ 20,700 gal
Southwest≈ 13 in≈ 6,900 gal
Pacific Northwest≈ 40 in≈ 21,200 gal
Worked example — Mid-Atlantic / Coastal (46 in): 1,000 ft² × 46 in × 0.623 gal × 0.85 ≈ 24,360 gal/yr per 1,000 ft² of roof. Scale by real roof area for the site total.
What it means for your townEstimate · illustrative
Climate — representative local rainfall
Build size
24,400gal per 1,000 ft² of roof / year — the real capture rate
731,000gallons harvested / year — that rate across your roof

Rain that lands on the sawtooth roof is filtered, UV-treated, and waters the zones from above — never the water that cools the servers. The capture rate is fixed physics and public rainfall; the yearly total is simply that rate across your actual roof. A Small build carries about 30,000 ft² of catchment across one module.

The rate is real — roof geometry (0.623 gal per inch per ft²), a 0.85 smooth-roof collection coefficient, and representative regional rainfall from NOAA / NCEI 1991–2020 station normals (e.g. Boston, Philadelphia, Atlanta, Chicago, Salt Lake City, Seattle). A region spans a range; your actual site uses its own local normal. The yearly total rides on roof area, shown at an illustrative ~30,000 ft² per flagship module — a design target until a real roof is built and measured.

Built by — GSS

The covered reservoir is a tank sized to ride the dry spells between storms: volume = daily draw × days of autonomy. That buffer-tank discipline — specify it, set it, service it — is exactly what Cole Candler’s Gas Station Supply has done across Central Virginia for decades. The tank is what turns an inch of rain into water on demand.

Measured / real
  • Rainfall normals — NOAA/NCEI 1991–2020, per site
  • 0.623 gal per inch per ft² (geometry)
  • Collection coefficient ≈ 0.85 (smooth roof)
  • First-flush diversion — standard practice
Design target
  • Actual roof catchment area
  • Zone water demand
  • Reservoir volume / days of autonomy
03 — The Roof, Across Climates

One roof, every climate.

“One sawtooth roof runs every market — it vents and shades through a Southern summer, seals and holds warmth through a Northern winter, and harvests a wet season, while the zones stay on setpoint.”
Verified language · IH Roof Across Climates schematic
HOW IT MOVES  ·  03 ROOFINTELLIGENTHARVESTSHADE SCREENthermal screen drawn→ reservoirSOUTHERN SUMMER — hot & humidNORTHERN WINTER — cold & snowWET SEASON — heavy rainvents open + shade drawn → sheds excess heatsealed + thermal screen → holds warmth ingutters channel runoff → harvests the rainOUTSIDE  vs  INSIDEcomfortOUTSIDE≈ 35°C≈ -6°C≈ 17°CZONESon setpointThe Roof, Across ClimatesOne sawtooth roof runs every market — it vents and shades through a Southern summer, seals andholds warmth through a Northern winter, and harvests a wet season, while the zones stay on setpoint.Powers the cloud. Feeds the town.Illustrative — schematic, not to scale
The Roof — vents + shade screen shed a Southern summer (≈ 35 °C), a sealed thermal screen holds a Northern winter (≈ −6 °C), gutters harvest a wet season — zones held on setpoint throughout. Outside temperatures illustrative. Animated schematic, official build-hub document.

The roof isn’t passive — it’s the building’s main climate actuator, and the same design runs in Texas, Kentucky, or Virginia. In summer it opens its vents and draws a shade screen to dump solar gain; in winter it seals and draws a thermal screen to hold warmth in; in a wet season its gutters route rain into the water loop. The zones underneath stay on setpoint while the outside swings.

The proof — the screens carry the load
Winter night — the thermal screen

A drawn aluminized screen traps a still-air layer and reflects the greenhouse’s own longwave heat back to the canopy. Published horticultural ranges (UMass Extension) put the effect at a real, measured band:

thermal screen  →  −30% to −50% heating demand  ·  canopy +3 to +5 °C at night
Summer day — the shade screen

Drawn in heat, the screen sheds a rated fraction of incoming solar before it ever loads the zones. Shade factor is a manufacturer-rated spec:

shade screen  →  sheds 40–60% of incoming solar (10–90% available)
The controller’s only job is to hold the zone band. The screens and vents are how it does it — proven horticultural hardware, not a new invention.
What it means for your townEstimate · illustrative †
30–50%of winter heating carried by the thermal screen
40–60%of summer sun shed by the shade screen

The same roof runs in Texas, Kentucky, or Virginia — it is the building’s main climate control. A Small build runs one module (≈30,000 ft² of actuated roof ). The screen percentages are proven horticultural ranges and don’t change with size — more building, the same self-reliance, less bought energy.

Real: thermal-screen savings 30–50% (UMass Extension); shade factors 40–60% (manufacturer-rated). Roof catchment area is illustrative and scales with module count.

Measured / real
  • Thermal-screen savings 30–50% (UMass Extension)
  • Aluminized longwave-IR reflectance mechanism
  • Shade factors 40–60% (manufacturer-rated)
  • Sawtooth natural-ventilation principle
Design target
  • Exact screen spec & shade % chosen
  • Vent area and zone setpoints
  • Site climate extremes (≈ values shown)
04 — The Nutrient Loop

Nothing is trucked away.

“Spent plants from the zones compost on-site in a sealed, aerobic, biofiltered vessel — no odor, no pests — and come back as soil for the next crop, with the surplus bagged for the town.”
Verified language · IH Nutrient Loop schematic
HOW IT MOVES  ·  04 COMPOSTINTELLIGENTHARVESTSEALED · AEROBIC · BIOFILTEREDno odor  ·  no pests  ·  no open pilesGREENHOUSEtrimmings out · soil infresh trimmingsrich compostAERATED & TURNEDair inclean air outodor scrubbedIN-VESSEL COMPOSTERenclosed — no open pilessurplus bagged for the townspent plants & trimmingsfinished compost → soil for the zones leachate contained & recirculated · never to the clean pondThe Nutrient LoopSpent plants from the zones compost on-site in a sealed, aerobic, biofiltered vessel — no odor, no pests —and come back as soil for the next crop, with the surplus bagged for the town. Nothing is trucked away.Powers the cloud. Feeds the town.Illustrative — schematic, not to scale
The Nutrient Loop — spent plants → enclosed in-vessel composter (aerated, biofiltered, odor scrubbed) → finished compost → soil for the zones; surplus bagged for the town; leachate contained, never to the clean pond. Animated schematic, official build-hub document.

When a crop finishes, its spent plants and trimmings don’t leave the site — they go into a sealed, aerobic, in-vessel composter. Enclosed means no open piles, no odor, no pests; the exhaust air is biofiltered and scrubbed, and the leachate is contained and recirculated — it never reaches the clean water pond. What comes out is finished compost that becomes the soil for the next crop. The surplus is bagged for the town. The loop closes on-site.

The proof — the loop closes on mass
Where the mass goes

Composting is mostly a controlled exhale. Cornell’s compost chemistry: with each microbial pass, roughly two-thirds of the carbon leaves as CO₂ and the rest stays as stable humus; the C/N ratio falls from about 30:1 toward 10–15:1. The result is a real, repeatable yield band:

finished compost  ≈  30–50% of input mass · remainder → CO₂ + water vapor, scrubbed
So the loop balances: trimmings out → about a third to a half returns as soil → surplus bagged for the town. The gaseous remainder is filtered; the liquid leachate is contained and recirculated. Nothing is trucked off-site.
Why we won’t put a tonnage here

The fraction is real. The absolute tonnage — pounds of trimmings, bags for the town — rides entirely on crop throughput, which only exists once a real greenhouse is running. So it stays a design target. We’d rather show you the honest mechanism than a number we can’t yet stand behind.

What it means for your townEstimate · illustrative †
30–50%of trimmings return as finished compost
0truckloads of crop waste hauled off-site

Every finished crop becomes the soil for the next, and the surplus is bagged for the town — across one module on a Small build. The yield fraction is real and repeatable. The absolute tonnage rides entirely on crop throughput, so — by deliberate choice — we won’t print a pound count we can’t yet stand behind.

Real: compost yield 30–50% of input mass; ~⅔ of carbon respired as CO₂ per pass (Cornell). The tonnage of compost bagged for the town stays a design target until a real greenhouse is running and weighed.

Built by — GSS

“In-vessel” means exactly that: a sealed tank, contained and serviceable — the same tank discipline Cole Candler’s team brings to the water and heat buffers. The vessel is what makes “no odor, no pests, nothing trucked away” a design spec instead of a hope.

Measured / real
  • Compost yield 30–50% of input mass
  • Carbon respiration ~⅔ as CO₂ (Cornell)
  • C/N falls ~30:1 → 10–15:1
  • Closed-loop, contained-leachate structure
Design target
  • Residue tonnage (rides on crop throughput)
  • Finished compost tonnage
  • Surplus bagged for the town

Four loops, one building. The constants are physics; the magnitudes wait for a site. That’s the honest line — and we’ll hold it all the way to the first harvest.

Powers the cloud. Feeds the town.

Sources & constants

  1. Rainfall normals (1991–2020): NOAA / NCEI Climate Normals — representative U.S. regional figures: Northeast ≈ 44 in, Mid-Atlantic / Coastal ≈ 46 in, Southeast ≈ 52 in, Midwest ≈ 39 in, Southwest ≈ 13 in, Pacific Northwest ≈ 40 in. Example stations: Boston, Philadelphia, Atlanta, Chicago, Salt Lake City, Seattle. A region spans a range; each site uses its own local normal.
  2. Rainwater geometry: 1 in over 1 ft² = 0.623 gal; collection coefficient ≈ 0.85 for smooth roofs after first-flush diversion.
  3. Heat capacity of water: cp = 4.186 kJ/kg·°C (1 BTU/lb·°F); Q = ṁ·cp·ΔT.
  4. Greenhouse screens: UMass Extension Greenhouse & Floriculture — energy/thermal screens 30–50% heating savings; shade factors 40–60% (10–90% available); aluminized longwave reflectance.
  5. Composting: Cornell Waste Management / Compost Chemistry — ~⅔ of carbon respired as CO₂ per pass; C/N 30:1 → 10–15:1; finished compost ≈ 30–50% of input mass.
  6. HDD equipment: Gladiator G30 (Wolf Machinery & Supply) — ≈ 29,000 lb thrust/pullback, 147 hp.

Loop schematics are the official Intelligent Harvest build-hub documents. Worked examples use real constants and public climate data; every site-specific magnitude is marked † as a design target until a site is built and measured.