Use this greenhouse heating water requirement calculator to turn operational assumptions into a clear planning estimate. Enter the measurements from your project, field, or greenhouse, then review the main result alongside the supporting totals. The calculator keeps the formula visible so you can check units, compare scenarios, and understand exactly which assumptions drive the answer.
The flow rate sizes circulation; it should not be interpreted as daily water consumption in a closed hydronic system.
Final pump, pipe, boiler, and expansion-system sizing should be checked by a qualified greenhouse heating designer.
A 500,000 BTU/h delivered load, 20°F temperature drop, and 90% effectiveness requires about 55.6 GPM. Over 12 hours, 40,000 gallons circulate through the closed loop.
The result changes directly with the quantities in the formula. Change one field at a time to see which operating assumption has the largest effect on flow.
Use the units printed beside each field. Convert measurements before entering them when a different unit is shown, because the built-in constants assume the displayed units.
Run separate scenarios for each period or operating condition, then add the applicable totals. A single blended input can hide important peaks and delays.
No. It includes only the losses, efficiency factors, or allowances shown in the input panel. Add separate allowances for conditions not represented.
Actual performance can differ because of measurement error, weather, equipment condition, work sequencing, material variability, and the quality of the assumptions entered.
| Output | Use |
|---|---|
| GPM | Hydronic circulation estimate |
| Daily volume | Total loop circulation |