Residential steam and warm air system components are introduced, along with methods of piping and duct layout. Maintenance, troubleshooting, replacement, alteration, and total system designs are emphasized to help the student learn the various concepts involved. Students must be simultaneously enrolled in HVAC224M. Prerequisite: HVAC114M, HVAC115M, HVAC119M, HVAC120M, HVAC134M, HVAC135M.