{
  "slug": "greenhouse-heating",
  "title": "Greenhouse Heating Cost Calculator",
  "heading": "Greenhouse Heating Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/greenhouse-heating",
  "summary": "BTU load and seasonal heating cost for any glazing type.",
  "description": "Estimate the heat loss through greenhouse glazing at your design temperature difference, then price the season's fuel for propane, natural gas, or electric heat.",
  "formula": "BTU/hr = surface area × U-value × ΔT.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=greenhouse-heating",
  "inputs": [
    {
      "id": "area",
      "label": "Glazing surface area",
      "kind": "number",
      "hint": null,
      "default": 1400,
      "unit": "sq ft",
      "min": 10,
      "max": null
    },
    {
      "id": "uValue",
      "label": "U-value of glazing",
      "kind": "number",
      "hint": null,
      "default": 0.7,
      "unit": null,
      "min": 0.2,
      "max": 1.3
    },
    {
      "id": "inside",
      "label": "Target inside temp",
      "kind": "number",
      "hint": null,
      "default": 60,
      "unit": "°F",
      "min": 32,
      "max": null
    },
    {
      "id": "outside",
      "label": "Design outside temp",
      "kind": "number",
      "hint": null,
      "default": 20,
      "unit": "°F",
      "min": -40,
      "max": null
    },
    {
      "id": "hours",
      "label": "Heating hours per season",
      "kind": "number",
      "hint": null,
      "default": 2400,
      "unit": null,
      "min": 1,
      "max": null
    },
    {
      "id": "fuelPrice",
      "label": "Propane price",
      "kind": "number",
      "hint": null,
      "default": 2.9,
      "unit": "$/gal",
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "btuHr",
      "label": "Peak heat load (BTU/hr)",
      "format": "number",
      "hint": null,
      "primary": true
    },
    {
      "id": "cost",
      "label": "Season propane cost",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "gallons",
      "label": "Propane needed (gal)",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "seasonMmbtu",
      "label": "Season energy (MMBTU)",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "kwh",
      "label": "Equivalent kWh",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Glazing surface area: 1400 sq ft",
      "U-value of glazing: 0.7",
      "Target inside temp: 60 °F",
      "Design outside temp: 20 °F",
      "Heating hours per season: 2400",
      "Propane price: 2.9 $/gal"
    ],
    "outputs": [
      "Peak heat load (BTU/hr): 39,200",
      "Season propane cost: $1,929",
      "Propane needed (gal): 665",
      "Season energy (MMBTU): 51.7",
      "Equivalent kWh: 15,165"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter glazing surface area (sq ft).",
      "Enter u-value of glazing.",
      "Enter target inside temp (°F).",
      "Enter design outside temp (°F).",
      "Enter heating hours per season.",
      "Enter propane price ($/gal).",
      "Read your peak heat load (btu/hr) on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "area": 850,
        "uValue": 0.42,
        "inside": 36,
        "outside": 12,
        "hours": 1450,
        "fuelPrice": 1.74
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "area": 1400,
        "uValue": 0.7,
        "inside": 60,
        "outside": 20,
        "hours": 2400,
        "fuelPrice": 2.9
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "area": 2250,
        "uValue": 1.1199999999999999,
        "inside": 96,
        "outside": 32,
        "hours": 3850,
        "fuelPrice": 4.64
      }
    }
  ],
  "limitations": [
    "Estimates assume standard, average conditions — local rules, pricing, and materials vary.",
    "Results are rounded for readability; add a buffer before ordering, booking, or committing.",
    "Double-check anything with a real cost attached against a local quote."
  ],
  "faq": [
    {
      "q": "Why the 0.55 factor?",
      "a": "Peak load only occurs at the design low. Averaged across a season, actual consumption runs roughly half to 60% of continuous peak."
    },
    {
      "q": "How much does double poly help?",
      "a": "It roughly halves the U-value versus single layer — usually the cheapest heating upgrade available."
    }
  ],
  "related": [],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Greenhouse Heating Cost Calculator (https://www.revenuelab.fyi/toolbox/greenhouse-heating)"
}