You may not know this, but the HVAC School podcast began before the website. When I started the podcast, I never intended to create a website, but there was more demand for quick tech tips than the podcast could hold. So, we started hvacrschool.com. In the same way, I never set out to create a […]

Have you ever seen a low-voltage transformer like the one shown above? It has multiple input (primary) taps for a good reason. It is common to find three-phase and single-phase equipment rated to operate on both 240v and 208v power. That is because three-phase power can either be 208v leg to leg when the building […]

Back in the “good old days,” controls were all analog and mechanical; that simply means they acted in a directly connected and variable manner based on a change in force. Both pneumatic (air pressure) and hydraulic (fluid pressure) systems are examples of mechanical or analog controls. When the pressure increases or decreases on a particular […]