The New Engineer — HVAC

Turn what you read in the overview into rules the tool replays on EVERY piece of the model, including the ones you were never shown. NOT NEEDED ON A MODEL ALREADY TREATED: when read_ifc_overview returns 'designation_existante', the units and fans are already designated - reuse them. Posting rules REPLACES that designation entirely: do it only when the user asks to start again, or when the designation plainly contradicts what they say. THIS IS HOW THE TOOL LEARNS A MODEL. read_ifc_overview gives you one line per family of types, not one per piece. You answer with RULES on those groups, and this tool applies them to the three thousand pieces. You never give a verdict piece by piece: the result stays deterministic because a program, not you, does the matching. THEN READ THE ANSWER BACK, AND EXPECT TO POST AGAIN. The answer gives every group with the role your rules gave it and how many pieces that is. A rule that is too wide shows up on one line — « Gaine rectangulaire cadree, 471 pieces, centrale_de_traitement_d_air » is a rule that turned every duct into an air handling unit. Narrow it and post again. Calling this tool costs nothing and may be repeated as often as you need. WHAT NEEDS A ROLE, AND WHAT DOES NOT. Plain ducts and fittings need none: they are network by nature, and the answer marks them segment_ou_raccord so you can see at a glance whether a rule caught them by mistake. What needs a role is everything else — air handling units, fans, fire dampers, balancing dampers, silencers, louvres, diffusers — plus whatever must be kept OUT of the network, such as access zones, equipment plinths or damper motors. THREE ROLE NAMES ARE FIXED, because circuits start from them: give air handling units, monoblocs and ventilation casings the role centrale_de_traitement_d_air, fans the role ventilateur, and SMOKE EXHAUST fans - including fans that bring compensation air for smoke exhaust - the role ventilateur_desenfumage - exactly these words. A smoke fan runs only i…

DETERMINISTIC: the same inputs always give the same result — from any AI, on any day. Figures come from the standard's tables and formulas, never from a language model's estimate. Every step is auditable. EN 378 applied to BUILDING projects, volume by volume. An installation does not occupy one room but several: the machine, the rooms crossed by refrigerant lines, the rooms served by indoor units. Each volume is classified on its own — access category (a/b/c) and location class (I–IV) — and each classification calls for its own measures. The tool answers per volume, never as a single verdict. It returns, for every volume: its classification and why, the charge limit from Tables C.1 and C.2 of EN 378-1 (with the C.2 formula computed when the table calls for it), whether the charge exceeds it, the EN 378-3 measures that follow, the applicable texts (EN 378-1 to -4, EN IEC 60079-10-1, SUVA 66139 and 2153) and the ventilation flow rates. FOUR CONFIGURATIONS COVER ALMOST EVERY BUILDING PROJECT. Bring the user's case back to one of them wherever possible: machine_en_local_technique chiller or heat pump, all refrigerant inside the machine, standing in a plant room -> c III enceinte_accessible_fermee all refrigerant inside a walk-in ventilated enclosure that stays closed even for maintenance -> the enclosure is c III, the room around it carries no requirement enceintes_inaccessibles one or more units, each in a manufacturer's non-accessible ventilated enclosure -> TWO analyses: the enclosure in operation (class IV, the manufacturer sizes and justifies it, ask him for the enclosure ventilation), and the plant room with the enclosure OPEN for maintenan…

DETERMINISTIC: the same inputs always give the same result — from any AI, on any day. Figures come from the regulation's annexes and thresholds, never from a language model's estimate. Every step is auditable. Swiss refrigerant regulation check (ORRChim / ChemRRV annex 2.10, OFEV synthesis of May 2026, rules adopted 29.10.2025) plus refrigerant data from EN 378-1 Annex E: GWP (AR4, the ORRChim basis), ODP, LFL, safety class, practical limit. Returns, for a given refrigerant and installation: the date from which machines using it can no longer be placed on the Swiss market (import from 01.01.2027, sale to third parties from 01.07.2027), the date from which filling with virgin refrigerant is banned, the period when only reclaimed refrigerant may be used, and the date from which all filling is banned. SCOPE: heating, air conditioning, building cooling and process cooling, data centres included. NOT food refrigeration, cold rooms or deep freezing: those are a different trade, and the tool declines them instead of answering. Use it whenever the user asks about a refrigerant in Switzerland — its GWP / PRG, flammability, whether a chiller, heat pump, split, VRF or cold room using it may still be sold or refilled — in any language: fluide frigorigène, Kältemittel, refrigerante, refrigerant, R-32, R-410A, R-290, CO2, NH3... The answer depends on the installation. The regulation distinguishes: use (building cooling, food refrigeration medium / low temperature / combined / deep freezing, process cooling, heat pump mainly for heating, ice rink), cooling capacity Q0K or heating capacity Q0H, self-contained (factory-built packaged unit) or not, split, direct expansion (incl. VRF), secondary coolant loop (chilled water / brine), air-cooled condenser and refrigerant charge. THIS TOOL ANSWERS ONE QUESTION ONLY: may the refrigerant still be sold and refilled in Switzerland, and until when. It says NOTHING about safety in the room - charge limits, machine room, detection, ventil…

Where the upload stands. When `state` is `depose`, `token` is the token to pass to read_ifc_networks.

Apply the names you propose, and get back the updated report. THE NAMES ARE YOURS, THE NETWORKS ARE NOT. You are naming what the tool measured; you are not changing what it measured. Nothing you send here alters a network, a part, or a correction. WHAT COMES BACK. The updated report, a 3D link where the user sees your names in colour, and a link to the corrective Dynamo script that writes the systems back into Revit. ALWAYS GIVE THE USER THE 3D LINK, and say plainly which names are yours. Networks are deterministic; names are a proposal. A user who cannot tell the two apart cannot check your work. AFTER THE USER HAS BEEN IN THE 3D VIEW, call read_ifc_networks again with the same token before saying anything about the model. They may have renamed what you proposed, assigned parts by hand, or refused a correction — and only a fresh read shows it.

Show an upload box in the conversation where the user can drop an IFC file (.ifc) of a building services model (HVAC, plumbing, heating). The file goes straight from the user's browser to thenewengineer.com - you never see it. CALL THIS when the user wants to analyse an IFC model and has not yet given you a link from thenewengineer.com. Then tell the user to drop the file in the box. When the upload is done, the box posts a message with a token. Use that token with read_ifc_networks. If no message arrives and the user says the upload is done, call ifc_upload_result with the upload_token returned here. Prototype: files up to the anonymous size limit of the site.

DETERMINISTIC: networks come from geometry, not from a guess. The same model always gives the same networks, from any AI, on any day. Read the networks of an IFC model already uploaded by the user. WHAT A NETWORK IS. A set of parts that touch each other, cut at equipment: a pump, an air handling unit, a chiller separates two systems, so the tool does not run through them. This is measured on the geometry — you cannot and need not check it. WHAT YOU GET, PER NETWORK state 'homogeneous' — a system exists, some parts were mis-named by the modeller; the tool will correct them. 'undetermined' — no system can be read. THIS is where you are useful. 'assigned' — the user or you already named it. system the dominant name, when there is one part_dominante the share of named parts carrying it equipements_voisins the NAMES of the machines this network is connected to. An undetermined network starting from 'AHU-Supply-L2' names itself — but only you can see it. systemes_existants every system name already in the model WHAT TO DO NEXT. Propose a name for each undetermined network, using the neighbouring equipment, the existing system names, and anything the user told you about the project's naming scheme. Ask the user for their list of planned systems if you do not have it. Then call name_ifc_networks. WHAT NOT TO DO. Do not rename a network the report calls 'homogeneous' unless its name plainly contradicts the equipment it is connected to — and then say why. Do not invent a network: you cannot see the geometry, and the tool already did that work. CALL THIS AGAIN WHENEVER THE STATE MAY HAVE MOVED. The token stays valid for 48 hours and is a key, not a snapshot: every call recomputes and returns the model AS IT IS NOW. The user works in the browser between your messages — renaming networks, assigning parts by hand, accepting or refusing correct…

CALL THIS FIRST, as soon as the user gives you a token - a link thenewengineer.com/ia/XXXX pasted in the conversation - BEFORE you answer anything, even when the user only says they will choose or do something themselves. It answers within seconds, while the network graph is still being built - use that time to think. THE USER WANTS TO CHOOSE THE UNITS THEMSELVES (« let me select », « je vais choisir les centrales »): the place to do it is the control page. Go on through the steps below until trace_duct_circuits (token only) returns 'lien_centrales', and GIVE THEM THAT LINK. Never tell them to select « in the interface » without the link: there is no other place to select. A MODEL ALREADY TREATED: if the answer carries 'designation_existante', an earlier session already designated the units and fans of this model. Reuse it: skip step 2, go straight to trace_duct_circuits, and show the user the designation you reused. Post new rules only if the user asks to start again. THE CIRCUITS OF A MODEL IN FOUR CALLS: 1. read_ifc_overview - this call: the types of the model. 2. apply_ifc_rules - your rules. Give air handling units, monoblocs and ventilation casings the role centrale_de_traitement_d_air, fans the role ventilateur, and smoke exhaust fans (and smoke compensation fans) the role ventilateur_desenfumage, exactly these words - and ONLY to equipment that holds a fan. Coils, heat exchangers, filters, silencers, dampers, VAV boxes are pieces of the network, not units - BUT a family NAMED as a unit (CTA, AHU, UTA, monobloc, caisson, centrale) is one, even when its type names its heat recovery: « BG_CTA_Echangeur à plaques » is an air handling unit. Its answer lists under 'equipements' every unit and fan of the model. 3. trace_duct_circuits with ONLY the token - it computes nothing, walks the networks from every unit and fan, and either returns the COMPLETE list of units and fans with the control p…

DETERMINISTIC: the same inputs always give the same result — from any AI, on any day. Figures come from the standard's tables and formulas, never from a language model's estimate. Every step is auditable. Size the expansion vessel and pressurisation of a closed heating or chilled-water circuit to EN 12828: static height, minimum pressure p0, fill pressure pa, final pressure pe, expansion volume, water reserve, nominal vessel volume with the standard vessel to buy, safety valve setting together with the minimum it must not fall below, pressure class of the lowest equipment, intermediate vessel when needed. Heights become pressures through the real density of the fluid, at the temperature that matters for each: the coldest for p0, the design temperature for the valve and the lowest point. Water and glycols therefore give different figures for the same height. Use it whenever the user asks to size or check an expansion vessel, pressurisation unit, pre-charge pressure or safety valve — in any language: vase d'expansion, maintien de pression, Ausdehnungsgefäss, Druckhaltung, vaso di espansione, vaso de expansión. Needs the installation water volume and THREE heights, all measured from the point where the expansion vessel connects to the network: - the highest point of the installation, above it; - the lowest point, usually below it (negative) or level with it; - the safety valve, which always sits on the heat generator or chiller. If the user does not know it, it is assumed 1 m above the vessel connection, and the result says so. Ask the user for the volume and the three heights before calling. NEVER invent a height: if the lowest point or the valve height is unknown, omit it. The result is then marked provisional and lists the questions to ask. Build your answer on `answer_outline`: it carries the assumptions, the questions and the link to the website,…

THE CIRCUITS THE FANS OF A MODEL ARE SIZED ON, found without anyone clicking and computed on the pressure-drop page, where the user confirms types and flows and reads the pressure drops. THE USER WANTS TO PICK THE UNITS THEMSELVES: call this tool with ONLY the token right away, and give them 'lien_centrales' - the control page, where a click turns a unit red and 'Send to my AI' sends you their choice. Without that link they have nowhere to select. ONLY UNITS AND FANS ARE EXCHANGED. The tool never sends you system names: it sends the air handling units and fans your rules found, each with what the network walk finds connected to it - geometry, not names. A unit is equipment with a FAN - air handling unit, monobloc, ventilation casing, fan. Coils, heat exchangers, filters, silencers, dampers are network pieces: if one shows up in the list (often as 'dans_le_reseau_de' another unit), your rules are too wide - fix them with apply_ifc_rules before choosing. But a family NAMED as a unit (CTA, AHU, monobloc) is one, whatever its type says. A LOW 'raccordement' MOSTLY MEANS MISSED UNITS: look for families named CTA, AHU, monobloc, caisson that got no unit role, and add them before sending the user anywhere. FIRST THE CHECK AND THE LIST, THEN THE CALCULATION. Called with only the token, once your rules are posted with apply_ifc_rules, it computes NOTHING and bills nothing. It walks the networks from every unit and fan and measures the share of the model's air pieces they reach ('raccordement'). Two answers: - CONNECTED (half of the air pieces or more): the COMPLETE list of units and fans ('centrales_et_ventilateurs', each with its number of connected networks) and 'lien_centrales', the CONTROL PAGE ('Network check' in English, 'Contrôle des réseaux' in French) - not a view-only page: every unit in its colour with its networks, where the user checks and CORRECTS the connections (identify or remove a unit, add a virtual AHU, connect or separat…

DETERMINISTIC: the same inputs always give the same result — from any AI, on any day. Figures come from the standard's tables and formulas, never from a language model's estimate. Every step is auditable. Deduce the water content of an installation from the expansion vessel already fitted. WHAT THIS IS FOR. Refurbishment, and site visits with no drawings. Sizing a new vessel, a new pump or a new generator needs the water content, and on an existing installation nobody has it: the drawings are lost, or never matched what was built. The vessel on the wall is the one piece of evidence still standing, and it was chosen from that very figure. ASK THE OPERATOR FIRST. Whoever filled or refilled the system knows the real figure — from the meter, the filling station, or the maintenance log — and that figure beats any deduction. This tool is what you use when nobody knows, or to check a number that looks wrong. It gets the conversation moving; it does not close it. HOW. The sizing calculation is run backwards: a trial water content is fed to the EN 12828 sizing, the resulting vessel is compared with the one on site, and the trial is adjusted until they match. The formulas are never rewritten in reverse — the answer cannot contradict the direct calculation, because it is the same code. WHAT THE ANSWER IS WORTH. A vessel is picked from a catalogue range: a 200 L unit covers everything needing between 141 and 200 L. The result is therefore A RANGE, never a single figure. And an oversized vessel — common — will overstate the content. Compare the range with what you see on site; it does not replace looking. It also assumes the vessel was sized correctly in the first place. If it was not, the deduction inherits the mistake — which is itself worth knowing: a range far from what the installation plainly holds means the vessel is wrong, and that is a finding in its own right.