Public Services and Procurement Canada Mechanical Design Guidelines

PSPC Mechanical Design Guidelines (PDF 591Kb)

MD 15116: 2006 Computer Room Air-conditioning Systems

Guidelines for Building Owners, Design Professionals, and Maintenance Personnel

Engineering and Technical Services

Advisory and Practices (Professional Services)
Professional and Technical Service Management
Real Property Branch
Public Services and Procurement Canada
Place du Portage, Phase III, 8A1-101
11 Laurier Street, Gatineau QC K1A 0S5

ISBN 0-662-43596-6

Public Information

All rights reserved. No part of this book may be reproduced by photocopying, recording, or any other means, or stored, possessed, or transmitted in or by any computer of other systems without prior written permission.

Public Services and Procurement Canada, Canada is pleased to present the Mechanical Design Guideline MD 15116: 2006 "Computer Room Air Conditioning Systems.

Computer rooms form an integral part of most federal buildings, and very often, they perform "mission critical" function, handling sensitive data on a 24/7 basis. As a result computer room air conditioning systems differ from general office air-conditioning systems in many significant ways. The cooling load is much higher and the requirements for temperature and humidity control are much stricter than for general purpose office buildings. The air conditioning systems requires a much higher level of reliability, as a breakdown in computer room air conditioning systems could lead to disruption of essential services and major economic losses. In addition, computer room air conditioning systems require greater flexibility to accommodate future changes. In most cases, control of computer room operation is independent of the rest of the building.

The objective of this document is to provide general guidance for the design and operation of mechanical systems for computer rooms, server rooms, Local Area Network (LAN) rooms, telecom equipment rooms and data centers. It provides guidance for the design requirements, estimation of cooling loads, selection of computer room mechanical equipment, and, the proper commissioning of the mechanical systems. This guideline is intended for use in new projects as well as for the retrofits of existing buildings.

This document has been developed by the Mechanical and Maintenance Engineering group, National Capital Area (NCA), in consultation with specialists and engineering professionals from throughout the regions. A previous version of this guideline was published in the 1980's but it is now obsolete due to rapid evolution of computer technology and an exponential increase in computer room equipment density. Many of the design techniques that were prevalent in the 80s are no longer applicable today.

One problem with many computer room air conditioning systems is simultaneous humidification and dehumidification, due to condensation in the cooling coils. This imposes an energy penalty on the cooling system. The present guideline addresses this issue, and suggests using only "dry coil" operation for maximum energy savings. Application of these guidelines will also improve equipment reliability, and minimize computer system failures.

It is important that clients, property managers, engineers, and, maintenance personnel be familiar with the contents of this document, so that they can apply the guidelines in a consistent manner for PSPC projects throughout Canada.

We encourage you to use this guideline whenever Computer Room Air Conditioning Systems are being planned, or where existing facilities require upgrades.

For more information regarding this guideline, please email



This document has been developed by the Mechanical and Maintenance Engineering group of Professional and Technical Programs, Architectural and Engineering Resources Directorate, Real Property Branch, Public Services and Procurement Canada.


Corrections, recommendations, suggestions for modifications or additional information and instructions that will improve this document are invited. For this purpose the attached form entitled "Request for change to this manual" may be used and mailed or faxed to the address shown. E-mail or other forms of electronic transmission may also be used for this purpose.


Any area of conflict between this document and the project brief / request for proposals shall be brought to the attention of the Project Manager as soon as it is noted.

MD15116: 2006
Computer Room Air Conditioning
Request for changes

Engineering and Technical Services
Advisory and Practices (Professional Services)
Professional and Technical Services
Real Property Branch
Public Works and Government Services Canada
Place du Portage, Phase III, 8A1-101
11 Laurier Street, Gatineau QC K1A 0S5

Type of change suggested:

Details of suggested changes:

If necessary, photocopy relevant page(s) of this manual and attach to this sheet. Page: Chapter: Paragraph no.:

Details of suggested changes:

(Use additional sheets if necessary)

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Table of contents

Chapter 1—Introduction

Chapter 2—Design Requirements

Chapter 3—Design Cooling Loads

Chapter 4—Computer Room Air Conditioning Equipment

Chapter 5—Measurements During Commissioning

Chapter 6

Chapter 7

Appendix A—Supplementary Material

Appendix B—Fire Protection Systems

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