Propane use planning for plant protection
Propane burn rate links heat demand to fuel planning for gardens and greenhouses. When you enter a heater load in BTU per hour, the calculator converts it to gallons and pounds of propane consumed. This helps growers compare heaters, schedule refills, and avoid temperature swings during frost events, cold starts, or extended cloudy periods.
Understanding ratings and efficiency inputs
BTU ratings can describe appliance input or delivered heat output. If you only know the required heat to hold a target temperature, efficiency converts that output to fuel input. For label ratings, choose input mode so the burn calculation reflects the stated consumption. This separation improves estimates across radiant tubes, portable convection heaters, and open-flame burners, where delivered heat varies.
Energy content and unit conversions
The energy content of propane is typically near 91,600 BTU per gallon, while density is about 4.24 pounds per gallon. Using both values allows the tool to report results in gallons per hour, pounds per hour, and daily totals. If you work with cylinder sizes in pounds, the density makes the tank runtime estimate consistent across cylinder and bulk supply options.
Runtime estimates for cylinders and tanks
Runtime depends on usable fuel, not the tank nameplate alone. A 20 pound cylinder filled to 80 percent contains about 16 pounds of propane, which is roughly 3.77 gallons. Dividing usable gallons by gallons per hour gives expected operating hours. For multiple heaters, total BTU scales linearly, so runtime drops proportionally. Use the estimate to decide whether you need a spare cylinder, manifolded tanks, or a larger storage plan.
Cost control, verification, and safe operation
Adding price per gallon or per pound turns consumption into budget numbers. Hourly and daily cost support seasonal forecasting and project costing for plant protection. Review results as ranges, because wind, ventilation, insulation, and thermostat cycling change duty cycle. Track actual refill intervals, then adjust efficiency or load assumptions for your site. Maintain equipment, check regulators, verify leak-free connections, and monitor clearances and airflow. For safety, keep cylinders upright, protect hoses from abrasion, and never run unvented heaters indoors without ventilation and CO alarms at all.
1) Should I choose heat output or input rating?
Use input rating when you have the appliance label BTU. Use heat output when you know required delivered heat, then enter an efficiency to estimate fuel.
2) Why is 80% fill common for cylinders?
Propane expands with temperature. Leaving vapor space improves safety and reduces the chance of pressure issues during warming conditions.
3) My runtime seems short. What could cause that?
High ventilation, wind, poor insulation, and continuous operation increase demand. Also confirm you entered the correct BTU value and the correct number of heaters.
4) Can I estimate cycling thermostats accurately?
Treat results as a full-load baseline. If your heater runs 50% of the time, multiply burn rate and cost by 0.5 for a practical average.
5) What propane BTU and density values should I use?
Defaults work for most planning. If you have supplier data, you can enter local values to match delivered fuel quality and temperature conditions.
6) Does altitude affect propane consumption?
Burners may derate at altitude and require different orifices. Your fuel use follows the adjusted BTU input needed to achieve the same heating outcome.