Math & Numbers

Heating Load Calculator (Envelope Transmission + Infiltration)

Estimate the heating (heat-loss) load of a room by the simplified steady-state method. Envelope transmission loss Q_trans = Σ(A_i·U_i·ΔT) over surfaces entered one per line as 'area,U' (U in W/(m²·K)). Cold-air infiltration loss Q_inf = 0.018·ACH·V·ΔT (W), where 0.018 W·h/(m³·K) ≈ ρ·c_p/3600. Total load = Q_trans + Q_inf, optionally multiplied by a safety factor (default 1.0). ΔT = indoor - outdoor (heating, >0). Temperature in °C/K/°F (only differences matter), area in m²/ft².

json· JSON resultOpen tool

Quick start

Call this tool from your code in three languages.

cURL

curl -X POST 'https://api.elysiatools.com/en/api/tools/heating-load-calculator' \
  -H 'Content-Type: application/json' \
  -d '{"surfaces":"50, 0.5\n10, 1.8","areaUnit":"m2","indoorTemp":20,"outdoorTemp":-5,"tempUnit":"°C","volume":120,"ach":0.5,"safetyFactor":1.1,"decimalPlaces":2}'

API reference

Send a POST request with your inputs as JSON. File parameters require a separate upload first.

Endpoint

HTTP

POST https://api.elysiatools.com/en/api/tools/heating-load-calculator

Parameters

Name	Type	Required	Description
surfaces	textarea	Yes	One envelope surface per line as 'area,U-value'. U in W/(m²·K). Area in the selected Area Unit. Example line: 50, 0.5
areaUnit	select	No	—
indoorTemp	number	Yes	Indoor design (comfort) temperature, in the selected Temperature Unit.
outdoorTemp	number	Yes	Outdoor design (winter) temperature, in the selected Temperature Unit.
tempUnit	select

MCP integration

Add this tool to your Model Context Protocol server so AI agents can list and call it.

Server configuration

Add this block to your MCP client configuration:

mcp.json

{
  "mcpServers": {
    "elysiatools-heating-load-calculator": {
      "name": "heating-load-calculator",
      "description": "Estimate the heating (heat-loss) load of a room by the simplified steady-state method. Envelope transmission loss Q_trans = Σ(A_i·U_i·ΔT) over surfaces entered one per line as 'area,U' (U in W/(m²·K)). Cold-air infiltration loss Q_inf = 0.018·ACH·V·ΔT (W), where 0.018 W·h/(m³·K) ≈ ρ·c_p/3600. Total load = Q_trans + Q_inf, optionally multiplied by a safety factor (default 1.0). ΔT = indoor - outdoor (heating, >0). Temperature in °C/K/°F (only differences matter), area in m²/ft².",
      "baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=heating-load-calculator",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

List available tools

After connecting to the SSE endpoint, list the exposed tools:

tools/list

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

Call this tool

Invoke the tool by its id, passing arguments built from its parameters:

tools/call

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "heating-load-calculator",
    "arguments": {
  "surfaces": "50, 0.5\n10, 1.8",
  "areaUnit": "m2",
  "indoorTemp": 20,
  "outdoorTemp": -5,
  "tempUnit": "°C",
  "volume": 120,
  "ach": 0.5,
  "safetyFactor": 1.1,
  "decimalPlaces": 2
}
  }
}

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