Boulder Community Health Center West Medical Building: Five Years of Guardian Hybrid Vacuum IG™ Success
Boulder Community Health Center West Medical Building
Five years of Guardian Hybrid Vacuum IG™ success
Lafayette, United States | August 20, 2024Located in the evolving area of East Boulder County, Boulder Community Health Center West Medical Building in Lafayette, Colorado is home to an eye clinic and ambulatory surgery center. The surgery center consists of two operating rooms and an area for retinal laser procedures. The building has accommodations for 4-5 medical practices.
Busy attending to their patients, the occupants don’t know their place of business is a valuable location for an important advancement in building construction: Vacuum insulated glass (VIG) technology. Guardian Glass’ collaboration with Boulder Associates led the architecture firm to specify 318 Guardian Hybrid Vacuum IG™ windows for the nearly 30,000 sf facility3. Completed in 2019, this building was the first new construction project to install Guardian Hybrid Vacuum IG windows, which combine the performance of Guardian Vacuum IG™ and the additional benefits of a traditional IGU.
‘The New Kid’ Braves a Brutal Environment
This area of Colorado is known for significant temperature fluctuations and abundant sunshine. That combined with the architect’s commitment to environmental stewardship meant Boulder Associates had a unique challenge to balance the two, making this project an ideal test site for an innovative, energy-efficient design.
To align with the client's goals of stable interior temperatures and year-round energy efficiency, the architect collaborated closely with the Guardian Vacuum IG team during this pilot project for the energy-efficient glazing prototype.
How VIG Works
Guardian Vacuum IG design seals two glass panes airtight, creating a vacuum in the space between the two panes. Guardian Hybrid Vacuum IG combines the performance of Guardian Vacuum IG with the additional benefits of a traditional IGU. With no air or gas between the panes, heat and cold have no medium by which to transfer, helping the unit deliver performance that exceeds a typical insulating glass unit4:
- Thermal: While a double pane Guardian Vacuum IG unit with a second-surface low-E coating – also known as a hybrid vacuum insulated glass – has an R-value of around R-4, hybrid vacuum insulated glass that incorporates a second Low-E coating boasts an impressive R-16, making its overall insulation comparable to that of a wall.
- Acoustic: Outdoor-indoor transmission class (OITC) is the typical measurement used to account for acoustic performance of an exterior facade as it emphasizes acoustic performance in the low to mid frequency ranges (i.e. noise from aircraft, trains, and automobiles). The higher the OITC rating, the greater the sound resistance the glazing will offer. In a typical thermally broken aluminum window system, the OITC improves from 26 for a double pane IGU to 31 for the same window system with Guardian Hybrid Vacuum IG.
Hybrid Improves Healthcare Built Environment
The architect specified Guardian Hybrid Vacuum IG windows for the building because of the product’s superior thermal insulation performance. Reducing the transfer of heat or cold through the glass helps deliver stable room temperatures and better energy efficiency to the building when comparing with standard double IGU configurations. Guardian Hybrid Vacuum IG units also deliver sound insulation to help contribute to a quiet indoor environment not polluted by external noise.
The Guardian Hybrid Vacuum IG units for the Boulder Community Health Center West Medical Building feature Guardian SunGuard™ SNX 62/27 low-E coating on surface 4. SunGuard SNX 62/27 low-E coated glass helps the building achieve energy-saving performance while balancing light transmission and reflectivity. The south, west and east elevation units also have SunGuard SNX 62/27 coating on surface 2 to further support the building’s energy efficiency.
Thermal performance of Guardian Hybrid Vacuum IG products compared to other glazing options for Guardian SunGuard™ SNX 62/27 low-E coating (glass thickness for all options is 4mm. Double pane, triple pane and hybrid options include a 12.7mm spacer with Argon):
Five Years In, People Prefer a Window Seat
Five years after installation, each window was evaluated with thermal imaging equipment.
Inside temperature of a Guardian Hybrid Vacuum IG unit and a traditional double pane unit installed after the original Guardian Hybrid Vaccum IG window was vandalized:
Images taken at 6:30am, overcast, 33°F (0.6° C) outside temperature. Inside temperature was 64°F (17.8° C) in unoccupied space.
The Guardian Hybrid Vacuum IG surface temperature is 5⁰F (2.8° C) warmer the traditional IG (interior temperature of the building was 64⁰F).
Analysis of all the windows in the building revealed that one of the Guardian Vacuum IGTM units failed, giving the installation a 99.7% success rate (314/315), which is consistent with traditional IG installations. When analyzed, the failed VIG had a diminished insulative performance comparable to the traditional IG, but did not completely lose its vacuum.
Property manager and occupant interviews revealed the employees were very pleased with their comfort levels regarding temperature and acoustics:
- Employees noted their offices were remarkably quiet, despite the building's location adjacent to a busy road.
- Workstations by the windows were highly sought-after.
- The property manager has not received any complaints related to the performance of the windows, compared to complaints from nearby buildings where draft affected occupant comfort.
- No one commented on noticing the micro-spacers characteristic of vacuum insulated glass.
The Next Frontier: Tempered VIG
"Having been available for over two decades, vacuum insulated glass has established its presence in the market; however, the advent of tempered VIG marks a revolutionary shift,” says Blush. “The thermal performance of tempered VIG, offering R-values twice that of its non-tempered counterpart, coupled with its enhanced strength, paves the way for its application in the commercial sector. This technology is poised to help reduce energy consumption and concurrently diminish the operational and embodied carbon footprint of the built environment." 5
Companies involved
ARCHITECT: Boulder Associates
GLAZIER: Steel City Glass LLC
1 Walls typically have a value between R13 - R23 depending on location, code, and age of the building.
2 Inside temperature of a Guardian Hybrid Vacuum IGTM unit was 62°and a traditional double pane unit was 57°. Images taken at 6:30 a.m. in April 2024, overcast, 33°F outside temperature. Inside temperature was 64°F in unoccupied space. See images above.
3 There are windows on the building that are not composed of Guardian Vacuum IG. That includes the corner windows that are butted together, glass doors, and any window that were broken and replaced.
4 Typical IGU makeup: The commercial construction standard in North America is a 1" insulating glass unit that consists of two ¼" lites of glass separated by a ½" Argon cavity.
5 Embodied carbon claims are based on comparing glass components of a 6mm/4mm/4mm Guardian Hybrid Vacuum IG versus the glass components of a 6mm/6mm/6mm triple IG. A VIG with 4mm glass can be used in place of a triple IG with 6mm glass due to the VIG’s enhanced mechanical strength.
6 Guardian Vacuum IG and Hybrid Vacuum IG units are certified by the Insulating Glass Certification Council (IGCC) confirming the long-term durability of both products. (IGCC #4909, #4910). Guardian Hybrid Vacuum IG units for this project were produced in a Guardian Glass pilot facility.