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Heating, gas & water calculators

Keep warm and supplied off-grid. Size a heater from your van or cabin's heat loss, estimate diesel and gas use, compare insulation, and plan fresh water and rainwater collection.

BTU to watts converterConvert BTU/h, watts, kW, kcal/h, horsepower and tons of cooling.Diesel heater fuel consumption calculatorDiesel per hour and per night, tank life and battery use of a diesel air heater.Propane tank and gas bottle calculatorHow long a propane or butane bottle lasts on a heater, hob or fridge.Van, caravan and cabin heat loss calculatorHeat loss in watts and BTU, and the heater size you need.Insulation R-value and U-value calculatorR-value (metric and US) and U-value for common insulation materials.Water tank capacity calculatorTank volume in litres and gallons, and how many days your water lasts.Rainwater harvesting calculatorRainwater you can collect from a roof per year and month.Water heating time and energy calculatorTime, kWh and battery Ah to heat water with an element, kettle or immersion.

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