Edge Computing: Considerations for Reliable Operation (ASHRAE TC 9.9 Technical Bulletin)

Overview

This technical bulletin explains that edge computing deployments carry a different environmental risk from conventional data centres. IT equipment in outdoor or semi-controlled enclosures can be exposed to cold, humid, dusty or polluted air when a door is opened for servicing. The bulletin discusses how this may affect equipment reliability and the manufacturer's warranty, and it proposes practical countermeasures.

The text runs through warranties, enclosure design, servicing practices, monitoring and site selection. Figures 3a to 3d show that opening an enclosure door can let in air that bypasses filtration. The moment of servicing should therefore be treated as a distinct and critical environmental condition, separate from steady-state operation.

The recommendations are concrete. The IT supplier's warranty environmental limits should be checked and the enclosure designed to the narrowest of them. For temperature change during servicing, the ASHRAE guideline is restated: 20 C in an hour and no more than 5 C in any 15 minutes. Technicians are advised to monitor IT inlet temperature and humidity in real time throughout servicing.

Being a short bulletin, it offers no detailed calculation method or numeric design tables, and it should be read alongside ASHRAE Thermal Guidelines, 5th edition. The overall message is that edge site design must account for servicing conditions as well as normal operation.

Key points

1. Opening an edge enclosure door can admit cold, humid, dusty or polluted air that bypasses filtration.
2. Check the IT supplier's warranty environmental limits and design the enclosure to the narrowest specification.
3. Temperature change guideline: 20 C in an hour and no more than 5 C in any 15 minutes.
4. Technicians should monitor IT inlet temperature and humidity in real time during servicing.
5. The bulletin covers warranties, enclosure design, servicing practices, monitoring and site selection.
6. Read it together with ASHRAE Thermal Guidelines, 5th edition.

Using it in design

• Add vestibule or servicing-condition checks to the edge enclosure template.
• Make a real-time IT inlet temperature and relative humidity sensor a standard component of the template.
• Add a servicing-weather warning to the operations checklist, with a rule to postpone servicing in unsuitable weather.
• Add a check comparing the enclosure's environmental limits with the warranty limits of the selected IT equipment.

Who should read it

Engineers who design, build and operate edge and distributed sites, and field service teams.

Related standards

• ASHRAE Thermal Guidelines 5th ed.

Publication details

Authors

ASHRAE TC 9.9

Publisher

ASHRAE

Year

2020

Document number

TC 9.9 Technical Bulletin (Sep 2020)

Document language

English

Source type

Standard

Access

Free to read

Licence

Copyright retained; citation only — the publisher’s terms apply to the original document

Citation