Hvac School - For Techs, By Techs

In this short podcast, Bryan talks about the hidden cost of killing radiant load, especially when it comes to installing radiant barriers in attics.  We sometimes get service calls about ducts sweating when they never used to sweat. If there are no problems with the system (i.e., the refrigerant charge, static pressure, airflow, supply air temperature, and blower speeds are all good), this type of situation can be a head-scratcher. Ask a customer if they've made any changes to the attic or equipment since the last service call, and there's a great chance they'll say something about adding a radiant barrier to keep the attic cooler. Ducts pick up heat from the surfaces in the attic. Radiant heat can come from the sun, but visible light isn't required for radiation to happen, and it can occur between objects. A radiant barrier prevents solar heat absorbed by the roof decking from radiating onto attic surfaces, but it doesn't change the dew point. When attic surfaces are cooler and the cool air passes through, t