# How can we calculate the power of a heating element?

• Bhisma Thapa
In summary, this person is asking for advice on how to safely build a pressure cooker that can heat water to a boiling point.

#### Bhisma Thapa

To be more specific, if i have to heat water 300l of water in one hour. What should the power of a heating coil?

Bhisma Thapa said:
To be more specific, if i have to heat water 300l of water in one hour. What should the power of a heating coil?
Welcome to the PF.

What are the starting and final temperatures? Do you need to boil it, or just heat it to a warmer temperature?

berkeman said:
Welcome to the PF.

What are the starting and final temperatures? Do you need to boil it, or just heat it to a warmer temperature?
Starting temp will be at room temperature.I need it for boiling.

Bhisma Thapa said:
Starting temp will be at room temperature.I need it for boiling.
This calculator will help you figure out how much energy and power are required to heat your water from room temperature to just short of boiling:

https://bloglocation.com/art/water-heating-calculator-for-time-energy-power

After that, it depends on whether you want to actually boil off the water, or keep it boiling for some period of time. Also, unless your container is perfectly insulated, you will lose some energy to the surroundings...

Can you say more about the application?

Bhisma Thapa and Asymptotic
Bhisma Thapa said:
What should the power of a heating coil?
Power is the rate of energy flow. You must deliver energy at a rate greater than the heat loss by all processes over all temperatures.
How quickly do you need to heat the water?
How well insulated is the tank?

berkeman said:
This calculator will help you figure out how much energy and power are required to heat your water from room temperature to just short of boiling:

https://bloglocation.com/art/water-heating-calculator-for-time-energy-power

After that, it depends on whether you want to actually boil off the water, or keep it boiling for some period of time. Also, unless your container is perfectly insulated, you will lose some energy to the surroundings...

Can you say more about the application?
Thanks.
It will be used like a pressurized electrical cooker.

Bhisma Thapa said:
It will be used like a pressurized electrical cooker.

Be careful and very vigilant about safety. It takes only one mistake to turn a pressure cooker into a bomb able to kill everyone in the room.

jim hardy and berkeman
Bhisma Thapa said:
It will be used like a pressurized electrical cooker.
anorlunda said:
Be careful and very vigilant about safety. It takes only one mistake to turn a pressure cooker into a bomb able to kill everyone in the room.
Agreed.

@Bhisma Thapa -- please send me a private message (click on my avatar and select "Start a Conversation") to explain your technical background and your project in detail. This thread will remain locked until we can figure out the level of danger in your project. Thank you.

jim hardy