Question

At winter design conditions, a house is projected to lose heat at a rate of 70000 Btu/h. The internal heat gain from people, lights, and appliances is estimated to be 6000 Btu/h. If this house is to be heated by electric resistance heaters, determine the required rated power of these heaters in kW to maintain the house at constant temperature.

Answer 1

The power to maintain constant temperature is 18.56kW

Step-by-step explanation:

Given

`Heat\ Loss = 70000\ Btu/h`

`Heat\ Gain = 6000\ Btu/h`

Required

Determine the power to maintain constant temperature

The power to maintain a constant temperature is the difference between heat loss and gain

i.e.

`Power = |Heat\ Loss - Heat\ Gain|`

This gives:

`Power = |70000\ Btu/h - 6000\ Btu/h|`

`Power = |64000\ Btu/h|`

`Power = 64000\ Btu/h`

Convert Btu/h to kW

`1 Btu/h = 0.00029 kW`

So:

`Power = 64000\ * 0.00029\ kW`

`Power = 18.56kW`

Hence;

The power to maintain constant temperature is 18.56kW