Boiler water heater

Boiler - calculate time and power supply of water heating in water tank.
You can switch to mode by radiobuttons:
- calculate time of water heating in hours and minutes
- calculate power requirement in kW
- you can check "F/US Gallon" for input data in °F instead of Celsia degree and volume of tank in US gallons instead litres

Description:
- input temperature of water (minimum +5°C or +41°F)
- output temperature at what temperature the water warmed want (maximum +100°C or +212°F)
- efficiency in % .. what is the efficiency of the device (90% - very good thermal insulation , 10% very poor thermal insulation of tank)
- volume ... volume of tank in liters or U.S. gallons = 3.78541178 liters
- energy input .... appliance power in kW (wattage appliances of device)

Example:
In tank is 21 gallons (volume) of water 41°F (input). We need to warm up water to 131°F (output).
Heating element have power 2 kW (energy input).
How long time will it take?
- you have to check box "°F/US Gallon" (if using US units)
- put data into correct edit fields
- pres OK