Alex Hall

This particular clients 24/7 critical central operations centre was served by CRAC units (precisions critical cooling systems). These systems appeared to have been originally installed to serve an IT / equipment room which was eventually converted to the current permanently occupied operations centre space.

To address ongoing comfort complaints by the operations centre operators, ACHall reviewed the existing installation, provided rectification upgrade options / costings and ultimately designed / supplied and installed the new replacement systems to address the existing comfort issues.

Project:
Client: 
HVAC Installation:

Project Details:

 

Operations centre HVAC Upgrade
Undisclosed
ACHall Airconditioning

Works comprised the replacement of existing CRAC systems with new comfort AC systems and all associated ductwork, air distribution systems and controls.

AC Halls engineering team confirmed that the existing system is of a typical equipment room cooling system configuration, relying on central precision HVAC systems, underfloor cooling air distribution to limited outlets within the space, and high level return air.  Of particular note was that:

"The current configuration does not assist in achieving even air distribution easily and is not the greatest in achieving an even space temperature gradient both vertically and horizontally throughout the space".

"The existing system provides floor level supply air at greater than space -3degC temperatures and is therefore unsuitable for the current space use and not in accordance with UFAD (underfloor displacement system) industry practice"

"Floor supply air grilles with high velocity airflows do little to mitigate draft and noise issues"

Conceptual designs were prepared by ACHall and presented for discussion along with project costings. A final design approach was adopted based on achieving a draft free space with temperature control and reduced noise conditions within the allocated project budget and program.

AC Halls engineered final solution comprised of the following key design elements:

  1. A dedicated system independent of the existing chiller plant (given that the operation centre operates 24/7).
  2. A reversed air distribution system approach (high level SA, low level RA) as standard DX systems are not easily modified to providing leaving air temp control (required to achieve a UFAD approach) with key focus on reusing existing floor and wall diffuser / grille openings.
  3. Careful diffuser selection (adjustable for commissioning) to ensure optimum air throw and distribution in consideration of the space parameters and a high level side wall throw configuration. Given the critical nature of the space, AC HAll worked with Holyoake Industries who assisted with grille selection and air pattern and air distribution modelling.
  4. Low noise AC system selections to minimise the perceived plant breakout and airborne noise levels by the operators.
  5. Utilising standard high quality manufacture comfort systems to allow for faster equipment procurement and short lead times necessary to meet the program.

The project has since which been completed successfully.