Case Study
Pennsylvania Health Care Facility – Reducing Operational Carbon
FreMarq Innovations was requested to provide input to a Midwest architectural firm on how Zero•Net™ products could help improve the insulating quality of an existing wall façade at a hospital in Pennsylvania. Due to a successful and established relationship on previous projects, the architects were aware of how FreMarq could provide value that other manufacturers could not.
Overview
In the initial approach, the architect evaluated leaving the existing glazing in place. The currently installed window’s poor thermal performance and condensation issues would be addressed by upgrading and upsizing the building’s mechanicals. Using this solution as a baseline, the design team investigated many alternative window replacement and glazing options. After much research and deliberation, the architect selected two options to be analyzed further for performance improvement.
Project Specs:
Exterior Temperature of 10°F
Interior Temperature of 75°F
Interior Relative Humidity of 40%
Assembled U Factor of Glazing Must be Max 0.37
Framing
Zero•Net™ PW2500 Pressure Wall (Curtain Wall)
Traditional Curtain Wall
The Study
This case study of a health care facility in Pennsylvania involved the renovation of a 31,800 square foot area on the 7th floor, consisting of 3,400 square feet of strip and punched windows. Original construction of the facility was in 1987 with a window-to-wall ratio of approximately 2:3. During the winter months, the hospital was experiencing occupant discomfort and problematic condensation, resulting in the need to renovate the exterior walls. After analyzing the existing conditions and the contract documents from the original build, it was determined that the existing glazing has an assembled U-value of 0.59
Option 1 – Traditional Curtain Wall
Using a 1” insulated glass in a traditional curtain wall that can achieve an assembled U factor of 0.37, meeting current code and providing a significant improvement over the existing glazing. However, after running a dew point analysis, this option would require radiant heat ceiling panels at each window opening to avoid condensation (Figure 1).
Option 2 – Zero•Net™ PW2500
Placing the same glass from option #1 into the FreMarq Zero-Net FW2500 window achieved an assembled U-factor of 0.28. This exceeded the code dramatically and when running a dew point analysis, the warmer interior frame temperatures eliminated the need for radiant heat panels above each window opening (Figure 2).
Project Collaborators
1. FreMarq Innovations provided thermal simulations and images, dew point analysis, details of the existing conditions of both options 1 and 2, and pricing of both options 1 and 2.
2. Leach Wallace Associates, the consulting engineer, provided the mechanical recommendations for the existing envelope and glazing option, using the information provided by FreMarq. The environmental conditions were provided by the owner.
3. The architectural firm provided the analysis and details of the existing conditions, as well as recommendations and details needed to bring the existing condition of the envelope up to current code. This included insulating the existing stone panels. The architects also created and presented the information for the owner.
Design Team Recommendation
Thermal simulations and dew point analyses were run using Therm 7.4 and Windows 7.4. The results were provided to Leach Wallace Associates for determining the mechanical requirements for each option, along with the costs (savings) as compared to the baseline. The architects and Leach Wallace Associates, both separate entities from FrēMarq Innovations, concluded that Option 2 was the most logical choice in terms of performance and cost. The ownership group concurred.
Medical Center – Cost Savings Analysis
Savings compared to existing glazing
- Values provided by Leach Wallace Associates. Air handling initial cost assumed at $25/CFM and radiant panel initial cast assumed at $470/LF.
- Values provided by Leach Wallace Associates. Two factors: fan energy savings and decreased airflow capacity both due to improved envelope.
- Reduced energy consumption due to improved window performance only. Amount is based on 2016 energy cost for year 1 with no increase in energy cost over the next 25 years. Value based on 3,400s square feet of glazing.