Best Practice Guide

Glossary

Introduction

Planning an Energy Program

Funding and Approval

Lighting

Building Envelope

Central HVAC System

Distributed Generation

Demand Response

Commissioning

Procurement Policy

Water Use

Education

Energy Efficiency in Telecommuting

Resources and Appendices

Lessons Learned

Best Practice Guide Glossary

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DIRECT EXPANSION (refrigeration) Return to list of terms

Any system that, in operation between an environment where heat is absorbed (heat source) and an environment into which unwanted heat is directed (heat sink) at two different temperatures, is able to absorb heat from the heat source at the lower temperature and reject heat to the heat sink at the higher temperature. The cooling effect is obtained directly from a fluid called a refrigerant that absorbs heat at a low temperature and pressure, and transfers heat at a higher temperature and higher pressure.

Source: California Energy Commission