This article is written by one of the smartest guys I know online, Neil Comparetto. Thanks, Neil! Recently, I posted a question in the HVAC School Group on Facebook that went like this: “When designing a residential duct system, what friction rate do you use?” As of writing this, only one answer was correct according […]

A 40VA transformer is rated for 40 VA or volt-amps on the secondary. For a typical 24 volt secondary, this is simply using Watt's law to calculate amperage. (For more information on Watt's or Ohm's laws, please check out this article HERE.) 40 ÷ 24 = 1.666666 ∞ (round up to 1.67 already) So, you […]

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 […]