heating

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.

This Old House's Ross Trethewey explains MERV filter ratings and how air filtration works, then shows how to build a localized DIY air filter, including a box fan with multiple filters.

Matt Risinger demonstrates a blower door test on a house, using a fan to measure air leakage and find where air gets in and out. It shows how the test reveals the quality of the build.

James Hoffmann demonstrates his AeroPress technique with a short recipe: 11g of coffee, 200g of just-boiled water, a 2-minute immersion, then a press. He explains why he skips rinsing, preheating and inverting.