This article is based on Ross Trethewey’s energy comparison sheet for fuels at select efficiencies and costs. All tables and their respective data belong to him. Ross Trethewey is the founder and lead engineer of TE2 Engineering and has served as the Home Technology Expert on “This Old House.” You can find a PDF file […]

This topic came up because I was testing out the new MR45 digital recovery machine. That machine goes off by itself when it hits a 20″ Hg vacuum. It's a cool feature, but it is good to know when that level of vacuum is overkill and when it's not enough according to EPA requirements. You […]

Ever since Nikola Tesla invented the modern induction motor, we have been struggling with varying the speed of motors efficiently and reliably. The trouble in the HVAC industry is that there are several different types of technologies in play, and they can easily get confused. ECM (electronically commutated motor) In residential and light commercial HVAC, […]