Published systems

A chilled-water air handler with reheat and a supply fan, published as an example. The design-point figures below come from the solver, not from a datasheet.

A packaged rooftop for a VAV floor: outside-air damper with an economiser and demand-controlled ventilation, DX coil on an inverter scroll, an electric heater for morning warm-up, and a supply fan that holds a duct static as the boxes throttle; the boxes themselves live on the building. Published as an example; the figures below are solved from this model.

An air conditioner that makes hot water from the heat it would otherwise throw away, the way a hot-water booster does it: a second, R134a heat pump whose evaporator is a plate exchanger on the A/C's hot gas. The A/C is a 20 kW-class split drawn from a supplier's own selection — coil faces, rows, fins, circuits and airflows, 7.5 K superheat and 5 K subcooling — on a Mitsubishi Electric LNB53 inverter rotary at its 60 rps rating speed. Between its compressor and its air condenser sits a **cascade exchanger**: the booster takes what the saturation difference across the plate drives, the air condenser rejects the rest, and the A/C condenses cooler for it. The booster's compressor is a catalog R134a heat-pump water-heater scroll standing in for the Mitsubishi SBB172, whose map is not published; its condenser heats water from 55 to 62 °C. The plate and the water side are an example's, not a maker's.

Gree's 14-ton GMV5 outdoor unit as this model runs it: the validated 20 HP machine scaled to the frame in every dimension — catalog R410A inverter scrolls behind an air-cooled condenser — modulated to the rated 168 kBtu/h (49.2 kW) the way the control runs it, holding Gree's published power input within −4 to +1 % from 25 to 39 °C outdoor at the 100 % combination ratio, capacity falling past 35 °C as Gree publishes it. Modelled from the maker's published data — not verified by the manufacturer. Published as an example; the figures below are solved from this model.

Drake Chillers' 30 HP packaged air-cooled chiller in its R407C build, as this model runs it: its own two Copeland ZB114KCE scrolls — the catalog's maps of the compressors its data sheet names — a stainless brazed-plate evaporator, and an air-cooled condenser under four fans. At 45 °F leaving water on a 95 °F day it makes the published 22.1 tons on 29.4 kW of compressor power — the sheet's EER of 8.44, on total power, less the fans — the two figures its evaporator and condenser are sized to; across the sheet's 45 °F row, 80 to 105 °F outdoors, it holds the published tons within 1.9 % and the compressor power within −2.8 to 0 %. The sheet holds its evaporator at one approach at every leaving temperature — it says the evaporator is selected upon requirements — so this fixed one makes up to 11 % more at 35 °F and about 14 % less at 65 °F. The PAC360D6 is the same machine on R404A. Modelled from the maker's published data — not verified by the manufacturer. Published as an example; the figures below are solved from this model.

The smallest evaporative condenser BAC publishes, drawn as a condensing unit: an R-22 Copeland ZR125KF scroll — 33 kW of cooling, sized under the condenser the way a unit with margin is — rejecting into a tube bundle under a recirculating spray, no fins, the air leaving saturated. Rated by its own sheet at 68.9 kW of base heat rejection on 3.32 m³/s of air — a condition the Series V EC sheet states, 105 °F condensing at a 78 °F wet bulb — and run as the evaporative wet coil with an isothermal tube side, the coil's share of the approach set where the maker's whole range derives. An open suction: couple any evaporator to it. Modelled from the manufacturer's published data — not verified by Baltimore Aircoil. Published as an example; the figures below are solved from this model.

A two-pipe fan coil on chilled water with an 8 kW electric heater: cooling from the loop, heat of its own — the smallest room unit that does both. Published as an example; the figures below are solved from this model.

Indirect-direct evaporative cooling: outside air over a water coil cooled by a small tower pack, then through a wetted pad, out through a supply fan; one pump round the loop. The dry-climate machine — two fans and a pump for a supply near the wet bulb. Published as an example; the figures below are solved from this model.

A dedicated outside-air unit for a densely occupied room: an exhaust-air plate core, a wrap-around heat pipe around the chilled-water coil, winter heating and a supply fan. Published as an example — the figures below are solved from this model, not copied from a datasheet.

The same machine as the one with radiators, with the radiators taken off: an outdoor coil taking heat from the air, a scroll compressor and a coaxial condenser, holding its leaving water for whatever draws on it. This is the shape a plant takes in a building — it serves no room, it holds a temperature, and the flats or the fan coils that drink from it are their own blocks. Published as an example; the figures below are solved from this model.

American Cooling Tower's ACC-106E — an ACC cooling tower, 112 nominal tons (491 kW): rated to cool 336 USGPM of water from 95 to 85 °F at a 78 °F entering wet bulb on 18.5 m³/s of air, the maker's own printed airflow, and drawn at those flows with an induced-draft fan on the leaving air, pulling through the fill. Open fill: the water meets the air directly — Braun's enthalpy-basis tower model. The model derives the machine's NTU from that one certified point, so it reproduces the rated leaving water exactly and predicts nothing else — one point per model is an input, not a validation. Modelled from the manufacturer's published data — not verified by American Cooling Tower. Published as an example; the figures below are solved from this model.

A frozen-store unit cooler: a fan and a 6 fpi DX coil with both refrigerant ports open, fed by a remote low-temperature condensing unit (boundary.refFeeds on its own page; the pair pinned hourly in a building). Published as an example; the figures below are solved from this model.

A chilled-water air handler for a campus building: outside-air damper with an economiser and a DCV floor, a chilled-water coil fed from the plant, a hot-water coil drawn as a gas boiler stand-in (fuel reported as gas at 85 %), a supply fan holding duct static. Published as an example; the figures below are solved from this model.

A packaged rooftop unit: outside-air damper with an economiser, DX coil on four scroll compressors, a gas duct furnace at 80 % and a supply fan, on a two-fan air-cooled condenser. Its heat is gas — reported as fuel, never as electricity — which is what separates a rooftop's winter from a heat pump's. Published as an example; the figures below are solved from this model.

A direct-expansion split — indoor fan and coil, scroll compressor, and an outdoor coil behind a two-fan bank that stages down to hold head pressure in cool weather. Published as an example of what a supplier's system page looks like; its performance below is solved live from this model.

Hitachi's 20 HP Set Free outdoor unit as this model runs it: two catalog R410A inverter scrolls behind an air-cooled condenser, modulated to the rated 56.0 kW the way the control runs it. Hitachi publishes the capacity grid — 56.0 kW from 25 to 35 °C outdoor, 52.7 at 40 — and the power input at the rating point only, 15.64 kW (EER 3.58), which this machine draws within 1 %; the capacity is reached at every published temperature. Modelled from the maker's published data — not verified by the manufacturer. Published as an example; the figures below are solved from this model.

A modular air-cooled chiller making chilled water: nine 14 kW-class inverter scroll modules on a pipe-in-pipe evaporator, rejecting through an air-cooled coil behind a two-fan bank. In the example building it serves no room — it holds 7 °C leaving water for the chilled-water air handler, coupled block to block. Published as an example; the figures below come from the solver, not from a datasheet.

The outdoor half of a split on its own: scroll compressor, air-cooled coil and a two-fan bank, with an open suction and liquid line. In a building it pairs with an indoor DX unit block — the refrigerant coupling pins what its suction carries every hour. Published as an example; solved live at a declared suction load.

A wing of guest-room fan coils run as one machine: a fan and a two-pipe chilled-water coil, breathing the rooms' own air. In the example hotel three such wings and the outside-air unit share one chiller through a water manifold. Published as an example; the figures below are solved from this model.

A dedicated outside-air unit for a store: a sorption wheel between the exhaust and the outside air (humidity efficiency 65 %), a wrap-around heat pipe around a chilled-water coil, a gas reheat and a supply fan — the outside air dried where it enters, most of its moisture handed back to the exhaust before the coil sees it, so the rooftops can recirculate. Published as an example; the figures below are solved from this model.

The plant a European house runs on: an outdoor coil taking heat from 7 °C air, a scroll compressor, a coaxial condenser heating a water loop, a circulator, and radiators giving it to the room. The radiators are a **hydronic emitter** — rated the way EN 442 rates one, an output at 75/65/20 °C and a characteristic exponent, with no geometry, because that is what a radiator maker publishes. They are deliberately oversized, which is what a heat-pump installer does: 34 kW at the EN 442 rating, more than twice the 14.7 kW the machine puts into them, so it settles at 52 °C flow (42 °C return) and a COP of 3.37 at the compressor instead of the 59 °C and 2.78 that boiler-sized radiators of 24 kW would have forced. A sixth of the running cost, bought with nothing but bigger radiators. Published as an example; the figures below are solved from this model.

Baltimore Aircoil's CXVB-102-0806-7.5 — a CXVB evaporative condenser rejecting 618 kW at a 40.6 °C condensing temperature and a 25.6 °C entering wet bulb, on 15.5 m³/s of the maker's own printed air, with a 5.6 kW fan. The heat comes from outside the drawing, because that is what this machine is: heat rejection, and the plant that sends it the heat is the customer's. Given exactly the rejection BAC certify, the model solves the condensing temperature the machine settles at — which is the reading, and the only figure here that is ours rather than theirs. The rating condition is an inference and the listing says so: BAC's sheets never define the condition of their Base Heat Rejection.

A recirculating cleanroom handler at twenty air changes: 5 % outside air, a chilled-water coil in face-and-bypass — the damper holds the humidity ceiling by mixing room air back, not an electric reheat — a winter heater, and three ebm-papst RadiPac K3G450 modules on the vendor's own pressure and power curves against 800 Pa of HEPA and duct static. Published as an example; the figures below are solved from this model.

The gas rooftop without its outside-air damper: a DX coil on a scroll, a gas furnace downstream of it for heat and reheat, a supply fan, a two-fan condenser — for a floor whose outside air comes from a dedicated unit. Published as an example; the figures below are solved from this model.