The work needed to evaporate water from washed clothes in a well-isolated room at 75°F can be calculated using the formula Q = m h_{fg}, where Q is the energy required, m is the mass of water, and h_{fg} is the latent heat of vaporization. Additionally, to account for the initial temperature of the water, the sensible heat must be included in the calculation: q = m h_{fg} + m c_{p} ΔT, where c_{p} is the specific heat and ΔT is the temperature change from 75°F to 212°F. This comprehensive approach allows for accurate estimations of energy requirements for evaporation and can be used to compare costs between line drying and using an electric dryer.
PREREQUISITESStudents studying thermodynamics, homeowners considering energy-efficient laundry options, and anyone interested in the physics of evaporation and energy consumption.
edgepflow said:The energy required is the mass of water multiplied by the laten heat of vaporization:
Q = m h_{fg}
Q = energy required
m = mass of water
h_{fg} = latent heat of vaporization
If you want to estimate how long it will take to evaporate naturally, search for "swimming pool evaporation equation."
The sensible heat can be included as follows:phinds said:No, he said it starts off at 75 degrees. Surely that has to be taken into account. I mean, it CAN'T take the same amount of energy to evaporate water at 1 degree above freezing as to do it to water at 1 degree below boiling.