Greenhouse Heating
Estimate BTU output needed to heat a greenhouse.
About Greenhouse Heating
A rough greenhouse heat load scales with the floor area and the temperature difference between inside and outside, times an insulation factor. The right heater keeps plants above their cold threshold on the coldest nights without overspending on oversized equipment.
Formula
Greenhouse Heating
BTU/hr ≈ floor area x 60 x temperature difference
- temperature rise
- Target inside temperature minus outdoor low
Worked example
With the default values below, Greenhouse Heating returns Heat Needed of 720,000. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Floor areaminimum 0 sq ft
- 300 sq ft
- Temperature rise neededminimum 0 F
- 40 F
Results
- Heat Needed
- 720,000 BTU/hr
- Electrical Kilowatts
- 211.02 kW
Step by step
- 1Values used
- 2Greenhouse Heating
- 3Heat Needed= 720,000 BTU/hr
- 4Electrical Kilowatts= 211.02 kW
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Greenhouse Heating calculated?
BTU/hr ≈ floor area x 60 x temperature difference A rough greenhouse heat load scales with the floor area and the temperature difference between inside and outside, times an insulation factor.
Why does Greenhouse Heating matter?
The right heater keeps plants above their cold threshold on the coldest nights without overspending on oversized equipment.
What values do I need to enter?
This calculator takes 2 inputs: Floor area, Temperature rise needed. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.