Which Bio Green heater does your greenhouse need?
Enter your greenhouse and the coldest night you expect. Results always show imperial and metric.
Greenhouse size
Style
Covering How much heat escapes
Coldest night outside Your usual winter low
Keep inside at least
Outlets you can use
Heat needed—BTU/h
Heat needed—Watts
Floor area—
Glazed surface—
Temperature lift—
Recommended
Quick guide — frost-free (40°F / 4°C) on a 20°F / −7°C night, 6 mm twin-wall:
How it's calculated: glazed surface × heat-loss value of the covering × temperature lift. This is the standard sizing method used across the greenhouse industry. The result is the heat your greenhouse loses on the coldest night; most nights need far less, and the thermostat only runs the heater when needed.
| Heater | Output | Greenhouse up to |
|---|---|---|
| Palma · 120 V | 750 / 1,500 W 2,560 / 5,120 BTU/h |
≈ 120–130 sq ft ≈ 11–12 m² |
| Phoenix · 240 V | 1,000 / 1,800 / 2,800 W 3,412 / 6,142 / 9,554 BTU/h |
≈ 215 sq ft ≈ 20 m² |