These days, humans have gotten all fancy-schmancy with their gas and electric water heaters. Heck, some are even using heat pumps to do the work as efficiently as possible. [HowToLou] got back to ...

For the purpose of making a hot tub, any style can suffice. The process of insulating will need to be adjusted if you go with ...

Designed to use biomass that might otherwise be wasted, such as wood, twigs, or other agricultural ... they can also be used to provide a large amount of hot water to something like an off-grid ...