16
votes
10answers
6k views

Is it more economical to use hot water before boiling or to bring cold water to a boil?

Since the arrival of our newborn, we have been using the stove to boil water in order to sterilize the nipples, bottles and rings. Which got me thinking, is it more economical to start off using hot ...
0
votes
1answer
462 views

is there a solar passive water condenser (from humid air) design anywhere? [closed]

i've looked around and i found only two related designs: active electric water condenser. solar passive water still (that distill dirty water) not quite what i was looking for...