climate change

A This Old House segment where Richard Trethewey installs a heat exchanger that uses waste heat from a central air conditioner to heat a swimming pool.

Dean Friedman's near-hour-long introduction to synthesis, covering the building blocks of sound and the controls on a synthesizer. He slowly adjusts knobs so viewers hear what each parameter does.

A woodworker shows how his table saw accident happened, why it happened and how to avoid a similar one. He describes severe hand lacerations from a blade contact.