I think about energy efficiency a lot, so my question of the moment is... when is the best time to do laundry? For me, my laundry consists of machine wash and machine dry.
Washer Efficiency
With the wash, the question is when is the best time to use a pretty much fixed amount of water and energy. I think that's when electricity production is at its most efficient, which is at night and on weekends. That's because the energy companies use their most efficient electricity generators 24 hours a day, but add less efficient generators as load increases.
Dryer Efficiency
With the dryer, the question is when is it easiest for the dryer to remove moisture. I think that's during low-humidity times. Dryers draw in air to work their magic, so the more dry the air is, the more quickly the laundry will dry.
Also, note again that dryers suck in air, and exhaust warm moist air outside. During extremely cold or hot weather, a heating system or air conditioning system will need to heat or cool this new outside air. It's good to minimize this expense too. Therefore, it is best to avoid doing laundry during very hot or very cold weather.
Conclusion
So I try to do laundry on dry nights and weekends. If it is particularly hot, cold, or damp outside, I'll put off laundry for another day.
Washer Efficiency
With the wash, the question is when is the best time to use a pretty much fixed amount of water and energy. I think that's when electricity production is at its most efficient, which is at night and on weekends. That's because the energy companies use their most efficient electricity generators 24 hours a day, but add less efficient generators as load increases.
Dryer Efficiency
With the dryer, the question is when is it easiest for the dryer to remove moisture. I think that's during low-humidity times. Dryers draw in air to work their magic, so the more dry the air is, the more quickly the laundry will dry.
Also, note again that dryers suck in air, and exhaust warm moist air outside. During extremely cold or hot weather, a heating system or air conditioning system will need to heat or cool this new outside air. It's good to minimize this expense too. Therefore, it is best to avoid doing laundry during very hot or very cold weather.
Conclusion
So I try to do laundry on dry nights and weekends. If it is particularly hot, cold, or damp outside, I'll put off laundry for another day.