Colorado College
OP-3: Building Design and Construction

The Robson Arena new building project completed in 2021 included a total building and parking garage area of 269,227 square feet located on a site area of 160,033 square feet.

Building Envelope and Landscape:

· The building exterior envelope is very sustainable, using energy efficient low-emissivity windows with automatic interior window shades for sun control, durable brick mass and durable stucco applied to the exterior walls, and minimal 6-inch thick insulated durable metal stud walls. The exterior envelope will have perforated metal sun screens wrapping around the building to cut glare and solar gain through windows (example photo below). The R-40 insulated roof is covered with a very sustainable “cool” white/highly reflective DuroLast PVC roof membrane. The roof membrane underlayment is upgraded to a very hard sheet-board system that is designed to prevent large hail damage or damage from mounting a PV solar system. The roof was designed to be PV solar ready for installing non-penetrating PVC heat weldable anchors for mounting PV solar rack systems. Conduits are already installed from the roof to the lower level cabinets in the electrical meter service room for net-metering connections. There is a plan to install solar PV energy storage batteries to be used for electrical demand peak shaving as an operating cost reduction measure.

· The Robson landscape and plant materials are designed to be low water usage other than a small grass area in a tree grove on the south side of the parking garage to be more friendly and compatible with the residential area landscape along Dale Street.

· There is a unique sustainable underground rainwater runoff retention and filter system installed in the southeast corner of the Robson Arena and parking garage. It sort of resembles a multiple row sewage septic system leach field which allows water to leach into the ground soils to reduce runoff.

Building Energy Use:

· Robson has a proposed 20.2% energy usage savings over a baseline system from ASHRAE 90.1-2010.

o The proposed energy use site intensity is 83.6 kBtu/ft² for Robson as opposed to a baseline system of 104.9 kBtu/ft².

o For comparison purposes Honnen (previous Hockey Rink) has a 4 year average of over 300 kBtu/ft².

· The HVAC system is comprised of central VAV air handling units with variable speed supply fans and energy recovery wheels. Heating hot water is provided from the campus high temperature hot water loop and is distributed to the building through a shell and tube heat exchanger and pumps with variable speed drives to modulate pump speed and maintain a minimum required differential pressure in the system.

· Cooling is provided from the campus chilled water loop and is distributed to the building by pumps with variable speed drives to modulate pump speed and maintain a minimum required differential pressure in the system. To support the additional cooling load of the arena, a new 400 ton water cooled chiller is being installed at the Central Plant. This new chiller will be coupled with two (2) existing 800 ton chillers to improve overall campus plant efficiency by converting the plant to a variable speed condenser water system and allowing a wider capacity range especially during fall and spring seasons when campus chilled water loads are low. The new 400-ton chiller has variable speed compressors and is capable of variable flow across both the chilled water and condenser water barrels.

· Dehumidification units with desiccant and energy recovery wheels are provided to maintain temperature and humidity in the ice bowl area.

· The ice system in the arena is provided by three (3) 40-ton water cooled chillers. The ice system also utilizes heat rejection from the chillers to heat the sub floor of the ice bowl to prevent freezing. In addition, during the winter season heat will be rejected from the ice chillers to the campus chilled water loop to support VRF systems in Tutt Library, Palmer Hall, Spencer and Cutler. This rejected heat will serve as the heat sink for the VRF condensing units in these buildings.

· Domestic hot water is provided from four (4) condensing water heaters operating in parallel to increase efficiency. Plumbing fixtures were selected as low flow to reduce indoor water consumption across the arena.

· Lighting in the arena is provided from dimmable LED fixtures to reduce electrical usage.

· Enhanced commissioning services are being provided for work at the Arena and the Central Plant chiller addition. These services are critical in ensuring the HVAC, ice, plumbing, electrical and envelope systems perform according to the Architect and Engineer’s design specifications. The commissioning agent was brought on early in design and is an integral team member all the way through building turnover. All systems will be put through functional performance testing to verify compliance with design documents, including the envelope which will have air barrier testing, IR thermography and air/water barrier testing of window systems.

· The building will be PV ready with electrical conduits installed for future installation of PV arrays on the arena and parking garage.

Colorado College Facility Design Guidelines Manual 2014, Rev. Nov. 21:
https://www.coloradocollege.edu/offices/facilities/plan-design-ops-maint/Facility-Design-Guidelines-Manual-Rev.-11-5-21.pdf

Facility Life-Cycle Design Guidelines for Sustainability, Rev 3-16-17:
https://www.coloradocollege.edu/offices/facilities/energy-management/FACILITY-LIFE-CYCLE-DESIGN-GUIDELINES-FOR-SUSTAINABILITY-Rev.-11-05-21.pdf