Ashrae 90.4 Pdf [work] -
| Feature | ASHRAE 90.1 | ASHRAE 90.4 | | :--- | :--- | :--- | | | Commercial buildings (offices, malls, hotels) | Data centers & Telco facilities | | Compliance Path | Prescriptive (insulation R-values, window U-factors) | Performance-based (MLC & ELC) | | Cooling Focus | Comfort cooling (people) | Process cooling (servers) | | Operating Schedule | Assumes variable occupancy (nights/weekends off) | Assumes 8,760 hours/year continuous operation |
To meet ASHRAE 90.4 requirements, engineers and designers can choose between three distinct compliance pathways:
ASHRAE 90.4 establishes the minimum energy efficiency requirements for the of data centers. It is a performance-based standard, meaning it sets efficiency targets to be met rather than prescribing specific equipment or design choices. ashrae 90.4 pdf
While summaries and interpretations are valuable, :
The MLC allowance can be very tight for small facilities because overhead doesn't scale linearly. Solution: The standard allows a "simplified approach" using packaged equipment with listed efficiencies. | Feature | ASHRAE 90
Aligning your data center design with ASHRAE 90.4 offers several major advantages beyond simple code compliance:
The latest edition can be purchased directly from ASHRAE at www.ashrae.org or by contacting ASHRAE Customer Service: Solution: The standard allows a "simplified approach" using
The measures the losses within the power distribution chain. It calculates the energy lost as electricity travels from the utility service entrance down to the IT racks. The ELC is split into three segments:
"Come on," Elias muttered, hitting 'refresh' on the simulation software. The data populated the spreadsheet, but the glaring red text at the bottom remained: FAILED - Mechanical Systems Efficiency below Standard.
He tried the official ASHRAE website. He navigated to the standards section, but the purchase price for the official document was steep, and his firm’s expense approval process took three days. He didn't have three days. He had hours.
: This calculates the sum of all power required for cooling, fans, pumps, and heat rejection equipment, divided by the total IT equipment power. Compliance factors vary by ASHRAE Climate Zone .