#duct leakage

Tech Tips:

The temperature of the refrigerant in the evaporator coil can really help us with diagnostics, but we need to know the targets we’re aiming for if we want to get the most out of it as a troubleshooting tool. If we take the return air temperature and subtract 35 degrees from that number, we get […]

Improving Humidity Control on the Cheap

This tech tip was submitted by Steve Rogers, the current president of The Energy Conservatory (TEC). Steve has been on the podcast several times in the past and is a valued contributor to HVAC School. Thanks, Steve! As summer approaches, HVAC technicians all over the US are preparing for those difficult conversations with occupants about […]

Where Do I Measure Delta T?

Over time, I’ve seen people use just about every type of temperature-measuring device in just about every location imaginable. From drilling tiny holes into rooftop unit panels to sticking a K-type wire into a piece of flex duct (I don’t remember why), I’ve done it all. Coming up through the trade, I’ve been TOLD to […]

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Real training for HVAC ( Heating, Ventilation, Air Conditioning and Refrigeration) Technicians. Including recorded tech training, interviews, diagnostics and general conversations about the trade.

In this short episode, Bryan talks about the situations when permits are not needed to install HVAC/R (or HVAC/R-related) components.

A few codes are universal in residential HVAC, including the International Residential Code (IRC) and the International Mechanical Code (IMC). The local municipality, also known as the authority having jurisdiction (AHJ), chooses which codes to adopt.

You do not need a permit to install plug-in, cord-connected appliances. However, you need UL-listed plugs. You can also replace plugs without needing a permit, but the ratings need to be correct. Anything less than 25v that doesn’t put out more than 50 watts of energy also doesn’t require a permit. Thermostats and many IAQ accessories, including UV lights, fall into this category.

Portable heating and ventilation appliances, including space heaters and portable cooling units or dehumidifiers, also don’t require permits. Evaporative or “swamp” coolers also don’t need a permit for installation. Self-contained units with 10 pounds or less of refrigerant and are actuated by motors with