Data Center Critical Cooling System Upgrade

Challenge:

Quantum Engineering Company was asked to decide what to do with the waste heat discharged by the spot coolers.  Options included discharging the air above the ceiling and allowing the central AHU’s and Chillers to address the heat (Options 1 & 2) or other options involved ducting the air to the perimeter, removing glass windows, installing temporary weather protection, and utilizing outside air to cool the spot cooler condensers (Options 3 & 4).

Project Approach:

In order to implement the project while minimizing loss of redundancy and loss of capacity, the decision was made to deploy temporary air cooled spot coolers while the existing cooling units were replaced one at a time.

Project Statistics:

Data Center: Approximately 2400 SF

Location:  Mid-Rise Office Building / 3rd Floor

Critical Load at Beginning of Project:  80kW

Cooling Capacity at Beginning of Project:  34 Tons / 119 kW

Cooling Capacity after Completion of Project:  65 Tons / 228 kW

Recommendation:

The final recommendation was to utilize outside air due to the very high costs associated with operating the large central station air handling units and central chilled water plant that would otherwise be disabled during off-hours (Option 3)

If you are interested in seeing the detailed analysis please review the comparison matrix below.

Temporary Cooling Options Matrix

College of William & Mary President’s House Restoration

Challenge:

Quantum Engineering Company was asked to recommend the best mechanical systems option while being sensitive to the building’s fabric and considering the Campus utility and Local utility options.

Project Statistics:

Originally Constructed:  1740’s

Use:  Residence for President of College: R-3

Height:  3-stories plus basement

Area:  Basement : 2128 SF

1st Floor: 2093 SF

2nd Floor: 2093 SF

3rd Floor: 1575 SF

Total: 7889 SF

Source of Heating: Campus Steam System

Source of Cooling:   Local Air-Cooled Chiller (Option 1)

Geothermal Based System (Option 2)

Campus Chilled Water System  (Option 3)

HVAC Distribution Type: Utilize Fan Coil Units (Option 1)

Utilize Central AHU’s (Option 2)

Utilize Central AHU’s VAV (Option 3)

Utilize High Velocity AHU’s (Option 4)

Source of Electric Power: Fed from adjacent Wren Building

Source of Natural Gas: New utility service (directional bore) to serve back-up generator located in garage

Research:

We conducted detailed field investigations to identify prior intrusions and identify extents of original fabric.

Analysis:

We prepared a list of possible mechanical system options and identified advantages and disadvantages of each option.

Quantum Engineering provided the following option matrices and then met with the owner and all stakeholders including facilities staff, maintenance staff, restoration architects, and historic campus advocate. If you are interested in seeing the detailed analysis please review the HVAC system comparison matrices below.

Recommendation:

The selected system type was a hybrid solution that best met the needs of the house and minimized intrusion on the historic fabric.  A high velocity (Unico) system was selected for the 3rd floor, a conventional constant volume, hot water, chilled water system was selected for the lower floors.  A local chiller was provided due to the disruption of trenching that would have been required for connection to the Campus chilled water system.  The heating system was connected to the Campus system since the infrastructure was already nearby.

HVAC System Comparison Matrices (PDF)

Location:  Williamsburg, VA