Maintaining commercial HVAC economizers – Part 1

Introduction

Economizers bring in outside air for ventilation and for free cooling.  However outside air may be too warm or too humid to offer free cooling or very cold.  Additional outside air that must be conditioned increases the cooling and/or heating load on the building.  Economizers that are properly designed, maintained and set can save significant amounts of energy. However economizers that are not functional, leaking, have sensors out of calibration or miss-set can have large energy penalties.  Maintaining economizers is critical to their function and to their impact on energy use.

This document sets out some basic information about commercial HVAC air-side economizers as well as an expanded maintenance checklist.  See: Maintaining commercial HVAC economizers – Part 2 for specific step-by-step economizer performance testing designed to be compatible with price sensitive commercial maintenance contracts. Please Press "Read More"

Maintaining commercial HVAC economizers – Part 2

Introduction

Economizers bring in outside air for ventilation and for free cooling.  However outside air may be too warm or too humid to offer free cooling or very cold.  Additional outside air that must be conditioned increases the cooling and/or heating load on the building.  Economizers that are properly designed, maintained and set can save significant amounts of energy. However economizers that are not functional, leaking, have sensors out of calibration or miss-set can have large energy penalties.  Maintaining economizers is critical to their function and to their impact on energy use.

This document sets out some specific step-by-step economizer performance testing designed to be compatible with price sensitive commercial maintenance contracts.  See: Maintaining commercial HVAC economizers – Part 1 for basic information about commercial HVAC air-side economizers as well as an expanded maintenance checklist.

Minimal visual inspection tasks (common to all economizers)

1.      Visually inspect the integrity and conditions of economizer components and wiring.

a.       Inspect wiring and wiring connections including the main economizer connection is plugged in, all wires connected to sensors, actuators and controllers

b.      Inspect components for excess corrosion, wear, and mechanical problems such as linkages and economizer hardware.

c.       Check eyebrow / economizer hood and filter assembly for proper sealing, and inspect integrity of moisture screen (bird Screen)

Please Press "Read More"