John Dalton was an English chemist and physicist born in 1766. He was born into a Quaker family of tradesmen, though he and his brother became teachers early in life. His family bought a Quaker school in Kendal, where he and his brother taught around 60 students.  Dalton separated from the church as a young […]

This article was written by HVAC contractor and Building Science Whiz, Michael Housh. Thanks, Michael! For a while, I’ve fallen into this camp where I feel Manual J overshoots heating loads. First off, I would like to say that Manual J is only as good as the information you give it, but we often run […]

Go to your truck, pick up a contactor, and look at it closely. You may find some interesting ratings you never noticed—things like terminal ambient temperature ratings and torque specs. One reading you may overlook is the RES AMPACITY of the contactor or relay. The RES rating is the RESISTIVE LOAD AMPACITY (amperage capacity) or rating. […]