About this calculator

How-to: enter greenhouse footprint, height, glazing type and the temperature you want to hold overnight during the coldest month. Peak heat loss Q = U × A × ΔT, where A is total envelope area and U is the glazing U-value (glass 6.0 W/m²K, twin-wall PC 3.0, single poly 6.5, ETFE double 2.8). Annual heat ≈ heating degree-hours × U × A ÷ 1000.

Frequently asked questions

Do I need to add ventilation losses?

Yes for a full model — typical infiltration is 0.5–1.5 air changes per hour. This tool sizes on conduction only, then applies a 20% oversize factor which usually covers infiltration in a well-built house.

Are thermal screens worth it?

Almost always. A single aluminised screen cuts night heat loss by 35–45% and pays back in 2–4 years at current EU gas prices.

Heat pump for a greenhouse?

Air-source heat pumps struggle below −5 °C. Ground-source or water-source (river / borehole) with buffer tanks work well and pair with off-peak electricity tariffs.

What does the Greenhouse Climate & Heating Requirement Calculator do?

Peak heat loss (kW) and annual heating energy (kWh) for a horticultural greenhouse — sizes the boiler/heater and estimates the fuel bill for glass, twin-wall polycarbonate or single-poly houses. How-to: enter greenhouse footprint, height, glazing type and the temperature you want to hold overnight during the coldest month. Peak heat loss Q = U × A × ΔT, where A is total envelope area and U is the glazing U-value (glass 6.0 W/m²K, twin-wall PC 3.0, single poly 6.5, ETFE double 2.8). Annual heat ≈ heating degree-hours × U × A ÷ 1000.

Is the Greenhouse Climate & Heating Requirement Calculator free to use?

Yes. Every calculator on Calcurly.com is free, works in your browser without sign-up, and can be embedded on your own website.

How accurate is the Greenhouse Climate & Heating Requirement Calculator?

Results are calculated in real time using industry-standard formulas. Treat the output as a well-informed estimate — always cross-check with local regulations, product datasheets, or a qualified agriculture & farming professional before committing to a purchase or a job.

What inputs does the Greenhouse Climate & Heating Requirement Calculator need?

Enter values for: Length (m), Width (m), Ridge height (m), Eave height (m), Glazing, Night set-point (°C). Sensible defaults are pre-filled where possible so you can start with a single change.

Can I embed the Greenhouse Climate & Heating Requirement Calculator on my own website?

Yes — copy the iframe snippet at the bottom of this page, or use the Embed Generator to customise the size. The embedded version stays in sync with the live calculator on Calcurly.com.