In one project the modules do not live apart: the heat loss calculation feeds heat pump sizing, radiant floor heating and ventilation, and an accepted client form feeds all four. Nothing moves without asking - every time, you see what comes in and what gets overwritten. This article describes which way the data flows, the module start screen, updates after a change in the source, and what the import leaves out on purpose.
Which way the data flows
Data flows as a tree, always one way:
- the client form - to the heat loss calculation (building data and the room list), to heat pump sizing (building parameters), to radiant floor heating (supply and return water temperatures, tubing), to ventilation (ventilation type, frost protection),
- the heat loss calculation - to heat pump sizing (building, rooms, heat loss), to radiant floor heating (rooms with their heat loss, temperature, type and story), to ventilation (rooms with their geometry).
The radiant floor heating and ventilation modules write nothing back to the heat loss calculation. When a module has two sources, it offers the richer one first: for radiant floor heating and ventilation, the rooms from the heat loss calculation; for the heat pump, the heat loss calculation.
Data from building documents read by the Algo assistant comes in by another route - Algo proposes values straight into the module's fields, and you confirm them. That is described in Algo, the AI assistant. Algo can also read a whole set of building plans and fill the heat loss calculation from them - rooms, building elements, windows and doors. How that works is in the heat loss calculation guide.
Every module stores and passes metric values, and every calculation stays metric, to EN 12831-1 and EN 1264. On an imperial account each module shows the same values in feet, ft², °F and Btu/h - so an import never changes a number, only how it is displayed.
The module start screen
A module that has no data yet opens on a start screen with the "Start with Algo", "I'll fill it in myself" and "Guide" buttons. In the heat loss calculation, heat pump sizing and ventilation, a line with the source sits under the buttons, with three figures from it. On an imperial account, for example: "Ready to bring in - Heat loss calculation: 7 rooms · 1,534 ft² heated · 28,662 Btu/h load" (142.5 m² and 8.4 kW on a metric account). The "Bring it into this module" button on that line brings in the data and opens the wizard. If a second source is also available, an "Also available" line with that source and its figures sits below, with a "Use this instead" button. "I'll fill it in myself" skips the import.
When there is nothing to bring in, the line says why and links to where you can change that:
- "This project has no heat loss calculation yet" - the button leads to the heat loss calculation,
- "N rooms still need completing" - the heat loss calculation is unfinished; "Finish the heat loss calculation",
- "The heat loss calculation needs corrections" - it has blocking issues; "Open the heat loss calculation",
- "The client sent the form back - accept it to bring the data in" - the form is waiting for your acceptance,
- "The client has not sent the form back yet" - the form is with the client.
On a free account the line shows totals; the heat loss of each room comes in with the full version of the project.
Updates after a change in the source
When the source changes after an import (you add a room in the heat loss calculation, for example), the module shows the "Heat loss calculation has changed" dialog the next time you open it, with the date of the previous import and a list of values: for fields, the current and the new value ("becomes"); for rooms, the counts of new, changed and removed ones. Values you edited yourself are marked "edited" with the warning "Your value will be overwritten". You check what to bring in ("Select all" / "Select none") and click "Bring in the ticked values". "Not now" postpones the question, and "Do not ask about this source" turns it off for this module.
You see the state of every source in the module settings under "Data sources": "up to date", "newer data available" or "declined", with the date of the last import and the "Bring in", "Bring in again" and "Restore" buttons (for a declined source). The "Clear data" button in a module also clears the remembered imports, so after clearing, the start screen with the source lines comes back.
Heat pump sizing and the calculated heat loss
In heat pump sizing, "Bring it into this module" brings in the heated area and the rooms (name, area, temperature) and stores each room's heat loss from the heat loss calculation. The heat pump sizing runs from that heat loss, not from the insulation class. The wizard has its usual four steps and every field stays editable. Bringing data in only adds: rooms added by hand stay, and the radiators and radiant floor heating entered in the rooms from the calculation stay too - only the name, area and temperature are overwritten. After changes in the heat loss calculation, the same "Heat loss calculation has changed" dialog works as in the other modules.
Older projects in which the heat pump was linked to the heat loss calculation switch to this way of working by themselves the first time you open them. If an older project has a different heat loss stored than the current calculation, the module shows the "The calculated heat loss has changed" dialog with the "Use the current load" and "Leave it as it is" buttons. Details in the article on heat pump sizing.
Radiant floor heating and rooms from the heat loss calculation
In radiant floor heating ("Underfloor heating" in the app), the rooms from the heat loss calculation come with their heat loss, temperature, type and story; the stories from the heat loss calculation are created automatically. After changes in the heat loss calculation the panel shows "The heat loss calculation has newer data" and the "Update data from the heat loss calculation?" dialog: the room data is overwritten with the heat loss results, rooms without loops can be moved to the right story, and rooms with drawn loops stay where they are. Manual changes in the overwritten rooms cannot be restored. How the module then uses each room's heat loss is in how to design radiant floor heating in HeatAlgo.
The heat loss calculation and ventilation: consistency checks
Ventilation reads the rooms from the heat loss calculation and writes nothing back. In turn, the heat loss calculation checks whether its losses agree with the designed ventilation: the ventilation type must be "Mechanical with heat recovery (MVHR)", the heat recovery efficiency assumed in the heat loss calculation is compared with the efficiency of the chosen heat recovery ventilator (HRV), and the supply and exhaust airflow in every room with the airflows from the ventilation module. The heat loss calculation shows the differences as remarks, with the values from both modules.
What the import leaves out on purpose
The import from the client form lists the skipped items with a reason - on the start screen, under the source line. The most common:
- a window or door with no matching room,
- hybrid ventilation - it has no equivalent in the heat loss calculation,
- a supply temperature given for a mixed system (the form also lists radiators, so the value may not be the radiant floor circuit's) or outside 68 °F-131 °F (20-55 °C),
- no usable temperature difference - then neither the supply nor the return temperature is imported,
- a tubing size not on the module's list,
- a range hood - the answer is about one room and the form does not say which,
- an open-combustion appliance - the form asks about an outdoor air supply, while the standard asks about drawing air from the room,
- declared airflows - ventilation derives them from the standard.
You enter everything skipped in the module by hand.
A HeatAlgo report follows EN 12831-1 and EN 1264, not ACCA Manual J, and is not accepted for permits or rebates.