The HVAC Knowledge Base

HVAC ENCYCLOPEDIA

In-depth articles on every HVAC system, component, and concept.

Diagram: Cooling Tower Operation and Maintenance
Encyclopedia

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 process to the atmosphere through the evaporation of water. Cooling tower…

Diagram: Psychrometrics for HVAC Technicians: Reading the Chart
Encyclopedia

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, it is one of the most essential branches of applied scie…

Diagram: Fan Laws: How Airflow, Pressure, and Power Relate
Encyclopedia

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 speed or air density affect three critical performance variables: airflow, press…

Diagram: Rooftop Units (RTU): Commercial HVAC Equipment Guide
Encyclopedia

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 house all major components in a single cabinet: compresso…

Diagram: HVAC for New Construction: Design Considerations
Encyclopedia

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 building envelope, mechanical systems,…

Diagram: Compressor Failure: Diagnosis, Causes, and Prevention
Encyclopedia

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 pressurizes refrigerant vapor, driving the thermodynamic cyc…