Greenhouse Heating Cost Calculator

Calculate heating requirements and costs for your greenhouse

Unit system selection
Greenhouse Dimensions
Temperature Settings
Insulation & Heating System

R-Value: 1.43

Efficiency: 85%

Usage & Energy Cost
Advanced Assumptions

Fine-tune the safety factors applied for infiltration losses and equipment sizing headroom. The defaults (20% and 15%) match most greenhouses. Increase the values for drafty structures or decrease them for highly sealed designs.

Default 20% covers typical air leakage and thermal bridging.

Default 15% prevents heaters from running at full load continuously.

Heating Analysis

Enter your greenhouse details to calculate heating requirements and costs

Calculation Methodology

Heat Loss Formula

Heat Loss (BTU/hr) = Surface Area (ft²) × U-Factor × Temperature Difference (°F)

Where U-Factor represents thermal conductance (1/R-value)

Material U-Factors (BTU/hr/ft²/°F)

  • • Single Poly: 1.15 (R-0.87)
  • • Double Poly: 0.70 (R-1.43)
  • • 6mm Polycarbonate: 0.91 (R-1.10)
  • • 16mm Polycarbonate: 0.50 (R-2.00)
  • • Glass: 1.10 (R-0.91)

Assumptions & Safety Factors

  • • Infiltration safety factor: 20% (adjustable via Advanced Assumptions)
  • • Equipment sizing headroom: 15% (adjustable via Advanced Assumptions)
  • • Efficiency factors: Natural gas 85%, Propane 85%, Electric 100%, Oil 80%
  • • Surface area includes walls, roof, and end panels

Data Sources

  • • U-values from ASHRAE Handbook of Fundamentals
  • • Safety factors per NGMA Design Guidelines
  • • Equipment efficiency standards from AHRI
  • • Formula validated against NRCS High Tunnel Guidelines
Last updated: January 2025 | Accuracy: Typically within 10-15% of actual costs

Energy Saving Tips

Insulation

  • • Double-layer coverings
  • • Seal air leaks
  • • Insulated north wall
  • • Foundation insulation

Solar Gain

  • • South-facing orientation
  • • Thermal mass (water barrels)
  • • Clear south glazing
  • • Remove snow promptly

Management

  • • Programmable thermostat
  • • Zone heating
  • • Night curtains
  • • Heat only when needed

Explore Other Calculators

Why Calculate Greenhouse Heating Costs?

Heating often makes up 50–80 % of a winter greenhouse’s operating budget. Oversizing equipment wastes money, while undersizing risks crop loss. Our calculator reveals the precise BTUs you need, the right heater size and projected costs per day, month and season—so you can grow year‑round without nasty surprises.

Enter your greenhouse dimensions, covering type, local energy prices and target temperature. The tool factors in R‑values, air infiltration and system efficiency to produce realistic numbers you can trust.

Frequently Asked Questions

How accurate is the greenhouse heating cost calculator?

We use proven heat‑loss equations plus a 20 % buffer for air leaks. When you input precise dimensions and local rates, the estimate is usually within 10–15 % of real‑world fuel bills.

Can I use Celsius and metric units?

Yes—switch the Imperial/Metric toggle to convert every input and result between feet/°F and metres/°C instantly.

Which heater type is cheapest to run?

Natural gas generally provides the lowest cost per BTU, followed by propane and then electric. Enter your local prices above to compare exact costs.

How can I reduce greenhouse heating expenses?

Upgrade insulation, add thermal mass, seal gaps, use night curtains and install a programmable thermostat. The recommendations list after each calculation highlights personalised savings ideas.

Does the calculator work for hoop houses or tunnels?

Absolutely. Measure the hoop house's length, width and arch height, select 'Single Layer Polyethylene' as the covering, and run the calculation for a reliable estimate.