Safety Standards & Certification
Refrigerant Handling Certification: EPA 608 Study Guide
What EPA 608 Certification Is and Why It Matters EPA Section 608 certification is a federal requirement for any technician who maintains,…
HVAC ENCYCLOPEDIA
In-depth articles on every HVAC system, component, and concept. Browse by topic or search below.
Safety Standards & Certification
HVAC Safety: Electrical Hazards and Refrigerant Handling
HVAC work ranks among the most hazardous occupations in the construction and service trades. Technicians routinely encounter voltages capable of causing fatal…
Cooling & Refrigeration
Cooling Tower Operation and Maintenance
What Is a Cooling Tower? A cooling tower is a heat rejection device that transfers waste heat from a building or industrial…
System Design & Sizing
Psychrometrics for HVAC Technicians: Reading the Chart
What Is Psychrometrics and Why Does It Matter? Psychrometrics is the study of the thermodynamic properties of moist air. For HVAC technicians,…
Airflow Ducts & Filtration
Fan Laws: How Airflow, Pressure, and Power Relate
What Fan Laws Are and Why They Matter Fan laws are a set of proportional relationships that predict how changes in fan…
Refrigerants & EPA
Refrigerant Recovery: Procedures, Equipment, and Regulations
What Is Refrigerant Recovery and Why Does It Matter? Refrigerant recovery is the process of removing refrigerant from an HVAC/R system and…
Airflow Ducts & Filtration
HVAC Filter Types: Fiberglass, Pleated, Electrostatic Compared
HVAC filters serve two essential functions: protecting heating and cooling equipment from debris and removing airborne particles that affect indoor air quality.…
Cooling & Refrigeration
Indoor Coil Icing: Why Your AC Freezes and How to Fix It
Indoor coil icing occurs when the evaporator coil inside an air conditioning system drops below 32°F (0°C) and moisture from indoor air…
Commercial & Specialty
Rooftop Units (RTU): Commercial HVAC Equipment Guide
A rooftop unit (RTU) is a self-contained HVAC system designed for outdoor installation, typically on the roof of a commercial building. RTUs…
System Design & Sizing
HVAC for New Construction: Design Considerations
Designing an HVAC system for new construction is fundamentally different from retrofitting an existing building. In new construction, every decision about the…
Components & Equipment
Compressor Failure: Diagnosis, Causes, and Prevention
The Role of the Compressor in HVAC Systems The compressor is the mechanical heart of every air conditioning and refrigeration system. It…
Heating Systems
Combustion Analysis: Testing Gas Appliance Efficiency
Combustion analysis is the systematic measurement and evaluation of flue gas products from gas-fired appliances to determine operating efficiency, verify safe operation,…