Tech Tips

The Four Ps of IAQ I’m not the first, second, or probably even the thirty-second person to write about improving indoor air quality problems using the four Ps approach. It’s a well-known thought process in the building science community—not sure if that’s the case in HVAC circles. The first P is for pollutants. In this […]

Most of the laws we refer to in air conditioning and refrigeration are pretty obvious and practical. Dalton’s law of partial pressures is no exception. John Dalton observed that the air pressure was equal to the added pressures of each gas that make up air. That means that the pressure and density of air can […]

This tech tip is a quick one on the difference between wiring universal condenser fan motors and why brown + white is the same wire as white. This one seems to confuse even experienced technicians, but it’s actually very simple once you see it. Now, keep in mind that wire colors ACTUALLY MEAN NOTHING, but […]

For those of you who use the MeasureQuick app for system diagnosis and performance testing, you may have noticed the “fan efficacy” results and wondered what it is. It is simply the CFM output of the system divided by the wattage used by the blower. It is only for the blower motor and has nothing […]

I’ve been reading a book called Cool: How Air Conditioning Changed Everything, and it got me interested once again in the history of air conditioning and refrigeration. Like many things, the people who are credited with “inventing” are the ones dogged enough to make an idea commercially successful, not the idealists forever tucked away in the […]

Photo Courtesy of Emerson What is Cascade refrigeration? “Cascade refrigeration” is a term you will hear more and more over the coming years, and while some of the systems may be very complex, the concept is actually pretty simple. Some refrigerants are well-suited for high and medium-temperature applications, and some are better suited for lower-temp […]

We all know (or should know) that venting refrigerant is a big no-no and can result in trouble from the EPA. There are many other potential violations, but two of them can easily occur if you aren’t thinking ahead at the disposal of mercury and oil. Mercury is found in fairly large quantities in the […]

There was a story that came out recently based on an ASHRAE study performed by David Yuill from the University of Nebraska. The study appeared to indicate that condenser coil cleanliness makes no difference on system performance and efficiency. Those of us who have worked in the field know that coil cleaning matters because most […]

Today’s tech tip is a video put out by my friend Brad Hicks from the HVAC in SC YouTube Channel. Thanks, Brad! Seal boots to prevent raccoon leaks. Ok, this has nothing to do with raccoons, but I like that photo. Whenever you are installing duct boxes (also called boots or cans) in an aftermarket […]